Sexually mediated phenotypic variation within and between sexes as a continuum structured by ecology: The mosaic nature of skeletal variation across body regions in Threespine stickleback (Gasterosteus aculeatus L.).

Ecological character displacement between the sexes, and sexual selection, integrate into a convergent set of factors that produce sexual variation. Ecologically modulated, sexually mediated variation within and between sexes may be a major contributor to the amount of total variation that selection can act on in species. Threespine stickleback (Gasterosteus aculeatus) display rapid adaptive responses and sexual variation in many phenotypic traits. We examined phenotypic variation in the skull, pectoral and pelvic girdles of threespine stickleback from two freshwater and two coastal marine sites on the Sunshine Coast of British Columbia, Canada, using an approach that avoids a priori assumptions about bimodal patterns of variation. We quantified shape and size of the cranial, pectoral and pelvic regions of sticklebacks in marine and freshwater habitats using 3D geometric morphometrics and an index of sexually mediated variation. We show that the expression of phenotypic variation is structured in part by the effects of both habitat marine vs freshwater and the effects of individual sites within each habitat. Relative size exerts variable influence, and patterns of phenotypic variation associated with sex vary among body regions. This fine-grained quantification of sexually mediated variation in the context of habitat difference and different anatomical structures indicates a complex relationship between genetically inferred sex and environmental factors, demonstrating that the interplay between shared genetic background and sexually mediated, ecologically based selective pressures structures the phenotypic expression of complex traits.

Bone remodeling and cyclical loading in maxillae of New Zealand white rabbits (Oryctolagus cuniculus).

Mammalian feeding behaviors are altered when mechanically challenging (e.g., tough, stiff) foods require large bite forces or prolonged mastication. Bony responses to high bite forces are well-documented for the mammalian skull, but osteogenesis due to cyclical loading, caused by repetitive chewing, is more poorly understood. Previous studies demonstrate that cyclical loading results in greater bone formation in the rabbit masticatory apparatus and in substantial Haversian remodeling in primate postcrania. Here we assess the relationship between cyclical loading and remodeling in the rabbit maxilla. Twenty male New Zealand white rabbits (Oryctolagus cuniculus) were raised on either an overuse or control diet (10 per group) for 48 weeks, beginning at weaning onset. The control group was raised on a diet of rabbit pellets (E = 29 MPa, R = 1031 J/m2 ), whereas the overuse group ate rabbit pellets and hay, which has high stiffness (E = 3336 MPa) and toughness (R = 2760 J/m2 ) properties. Hay requires greater chewing investment (475 chews/g) and longer chewing durations (568 s/g) than pellets (161 chews/g and 173 s/g), therefore causing cyclical loading of the jaws. Remodeling was measured as osteon population density (OPD), percent Haversian bone (%HAV), and osteon cross-sectional area (On.Ar). The only significant difference found was greater On.Ar in the alveolar region of the maxilla (p < 0.001) in the overuse group. The hypothesis that cyclical loading engenders Haversian remodeling in the developing maxilla is not supported. The continuation of modeling throughout the experimental duration may negate the need for remodeling as newly laid bone tends to be more compliant and resistant to crack propagation.

Transitioning out of prognostic talk in discussions with families of hospice patients at the end of life: A conversation analytic study.

OBJECTIVE: To examine transitions out of prognostic talk in interactions between clinicians and the relatives and friends of imminently dying hospice patients. METHODS: Conversation analysis of 20 conversations between specialist palliative care clinicians and the families of imminently dying patients in a hospice. RESULTS: Following the provision and acknowledgement of a prognostic estimate, clinicians were able to transition gradually towards making assurances about actions that could be taken to ensure patient comfort. When families raised concerns or questions, this transition sequence was extended. Clinicians addressed these questions or concerns and then pivoted to action-oriented talk, most often relating to patient comfort. CONCLUSION: In conversations at the end of life, families and clinicians used practices to transition from the uncertainty of prognosis to more certain, controllable topics including comfort care. PRACTICE IMPLICATIONS: In a context in which there is a great deal of uncertainty, transitioning towards talk on comfort care can emphasise action and the continued care of the patient and their family.

Managing uncertainty and references to time in prognostic conversations with family members at the end of life: A conversation analytic study.

BACKGROUND: When patients are likely to die in the coming hours or days, families often want prognostic information. Prognostic uncertainty and a lack of end-of-life communication training make these conversations challenging. AIM: The objective of this study is to understand how clinicians and the relatives/friends of patients at the very end of life manage uncertainty and reference time in prognostic conversations. DESIGN: Conversation analysis of audio-recorded conversations between clinicians and the relatives/friends of hospice inpatients. SETTING/PARTICIPANTS: Experienced palliative care clinicians and relatives/friends of imminently dying hospice inpatients. Twenty-three recorded conversations involved prognostic talk and were included in the analysis. RESULTS: Requests for prognostic information were initiated by families in the majority of conversations. Clinicians responded using categorical time references such as 'days', allowing the provision of prognostic estimates without giving a precise time. Explicit terms such as 'dying' were rare during prognostic discussions. Instead, references to time were understood as relating to prognosis. Relatives displayed their awareness of prognostic uncertainty when requesting prognostic information, providing clinicians with 'permission' to be uncertain. In response, clinicians often stated their uncertainty explicitly, but presented evidence for their prognostic estimates, based on changes to the patient's function previously discussed with the family. CONCLUSION: Prognostic uncertainty was managed collaboratively by clinicians and families. Clinicians were able to provide prognostic estimates while being honest about the related uncertainty, in part because relatives displayed their awareness of uncertainty within their requests. The conversation analytic method identified contributions of both clinicians and families, and identified strategies based on real interactions, which could inform communication training.

Communication between healthcare professionals and relatives of patients approaching the end-of-life: A systematic review of qualitative evidence.

BACKGROUND: Effective communication between healthcare professionals and relatives of patients approaching the end-of-life is vital to ensure patients have a 'good death'. To improve communication, it is important to first identify how this is currently being accomplished. AIM: To review qualitative evidence concerning characteristics of communication about prognosis and end-of-life care between healthcare professionals and relatives of patients approaching the end-of-life. DESIGN: Qualitative systematic review (PROSPERO registration CRD42017065560) using thematic synthesis. Peer-reviewed, English language articles exploring the content of conversations and how participants communicated were included. No date restrictions were applied. Quality of included studies was appraised using the Joanna Briggs Institute Critical Appraisal Checklist for Qualitative Research. DATA SOURCES: An electronic database search of CINAHL, MEDLINE, PsycINFO and EMBASE was performed. RESULTS: Thirty-one papers were included. Seven themes were identified: highlighting deterioration; involvement in decision-making, post-decision interactional work, tailoring, honesty and clarity, specific techniques for information delivery and roles of different healthcare professionals. Varied levels of family involvement in decision-making were reported. Healthcare professionals used strategies to aid understanding and collaborative decision-making, such as highlighting the patient's deterioration, referring to patient wishes and tailoring information delivery. Doctors were regarded as responsible for discussing prognosis and decision-making, and nurses for providing individualized care. CONCLUSION: Findings suggest training could provide healthcare professionals with these strategies to improve communication. Interventions such as question prompt lists could help relatives overcome barriers to involvement in decision-making. Further research is needed to understand communication with relatives in different settings and with different healthcare professionals.