Complexity of mental geometry for 3D pose perception.

Biological visual systems rely on pose estimation of 3D objects to navigate and interact with their environment, but the neural mechanisms and computations for inferring 3D poses from 2D retinal images are only partially understood, especially where stereo information is missing. We previously presented evidence that humans infer the poses of 3D objects lying centered on the ground by using the geometrical back-transform from retinal images to viewer-centered world coordinates. This model explained the almost veridical estimation of poses in real scenes and the illusory rotation of poses in obliquely viewed pictures, which includes the "pointing out of the picture" phenomenon. Here we test this model for more varied configurations and find that it needs to be augmented. Five observers estimated poses of sloped, elevated, or off-center 3D sticks in each of 16 different poses displayed on a monitor in frontal and oblique views. Pose estimates in scenes and pictures showed remarkable accuracy and agreement between observers, but with a systematic fronto-parallel bias for oblique poses similar to the ground condition. The retinal projection of the pose of an object sloped wrt the ground depends on the slope. We show that observers' estimates can be explained by the back-transform derived for close to the correct slope. The back-transform explanation also applies to obliquely viewed pictures and to off-center objects and elevated objects, making it more likely that observers use internalized perspective geometry to make 3D pose inferences while actively incorporating inferences about other aspects of object placement.

Fall Trajectories in Older Men: Trajectories of Change by Age and Predictors for Future Fall Risk.

BACKGROUND: Very little is known about specific trajectories or patterns of falls over time. Using the well-characterized cohort of the Osteoporotic Fractures in Men Study (MrOS), we classified individuals by fall trajectories across age and identified predictors of group assignment based on characteristics at baseline. METHODS: Using an analysis sample of 5976 MrOS participants and 15 years of follow-up data on incident falls, we used group-based trajectory models (PROC TRAJ in SAS) to identify trajectories of change. We assessed the association of baseline characteristics with group assignment using one-way analysis of variance (ANOVA) and chi-square tests. Multivariable logistic regression was used to analyze the outcome of the high risk fall trajectory groups compared to the low risk groups. RESULTS: Changes in rates of falls were relatively constant or increasing with five distinct groups identified. Mean posterior probabilities for all five trajectories were similar and consistently above 0.8 indicating reasonable model fit. Among the five fall trajectory groups, two were deemed high risk, those with steeply increasing fall risk and persistently high fall risk. Factors associated with fall risk included body mass index, use of central nervous agents, prior history of diabetes and Parkinson's disease, back pain, grip strength, and physical and mental health scores. CONCLUSIONS: Two distinct groups of high fall risk individuals were identified among five trajectory groups, those with steeply increasing fall risk and persistently high fall risk. Statistically significant characteristics for group assignment suggest that future fall risk of older men may be predictable at baseline.

Needs of family caregivers of hospitalised adults with dementia during care transitions: a qualitative study in a US Department of Veterans Affairs Hospital.

OBJECTIVE: To identify the needs of caregivers of hospitalised adults with dementia in the hospital and during care transitions. DESIGN: Pragmatic qualitative inquiry with semi-structured interviews. SETTING: Michael E. DeBakey Veterans Affairs Medical Center in Houston, Texas, USA. PARTICIPANTS: 12 family caregivers (family member (n=11); friend (n=1)) and 15 health professionals (hospital medicine physicians (n=4), inpatient nurse case managers (n=2), social workers (n=4), outpatient geriatrics providers (n=2), a primary care provider (n=1), geriatric psychiatrists (n=2)) were interviewed. Caregivers were recruited while their care recipient was hospitalised and were interviewed at least 2 weeks after the care recipient was discharged from the hospital. Health professionals were eligible for the study if they provided care to patients with dementia in the inpatient or outpatient setting. RESULTS: Four recommendations emerged from the analysis: (1) engage caregivers as partners in the care team, (2) provide dementia-specific information and training, (3) connect caregivers to home and community-based services and (4) provide care navigation and support for the caregiver posthospitalisation. CONCLUSIONS: Hospital care transitions are challenging for caregivers of hospitalised adults living with dementia. Care transition interventions designed to support caregivers with tailored, dementia-specific information and services are needed.

Greater Covid-19 vaccine uptake among enrollees offered health and social needs case management: Results from a randomized trial.

OBJECTIVE: To investigate Covid-19 vaccination as a potential secondary public health benefit of case management for Medicaid beneficiaries with health and social needs. DATA SOURCES AND STUDY SETTING: The CommunityConnect case management program for Medicaid beneficiaries is run by Contra Costa Health, a county safety net health system in California. Program enrollment data were merged with comprehensive county vaccination records. STUDY DESIGN: Individuals with elevated risk of hospital and emergency department use were randomized each month to a case management intervention or usual care. Interdisciplinary case managers offered coaching, community referrals, healthcare connections, and other support based on enrollee interest and need. Using survival analysis with intent-to-treat assignment, we assessed rates of first-dose Covid-19 vaccination from December 2020 to September 2021. In exploratory sub-analyses we also examined effect heterogeneity by gender, race/ethnicity, age, and primary language. DATA COLLECTION AND EXTRACTION METHODS: Data were extracted from county and program records as of September 2021, totaling 12,866 interventions and 25,761 control enrollments. PRINCIPAL FINDINGS: Approximately 58% of enrollees were female and 41% were under age 35. Enrollees were 23% White, 12% Asian/Pacific Islander, 20% Black/African American, and 36% Hispanic/Latino, and 10% other/unknown. Approximately 35% of the intervention group engaged with their case manager. Approximately 56% of all intervention and control enrollees were vaccinated after 9 months of analysis time. Intervention enrollees had a higher vaccination rate compared to control enrollees (adjusted hazard ratio [aHR]: 1.06; 95% confidence interval [CI]: 1.02-1.10). In sub-analyses, the intervention was associated with stronger likelihood of vaccination among males and individuals under age 35. CONCLUSIONS: Case management infrastructure modestly improved Covid-19 vaccine uptake in a population of Medicaid beneficiaries that over-represents social groups with barriers to early Covid-19 vaccination. Amidst mixed evidence on vaccination-specific incentives, leveraging trusted case managers and existing case management programs may be a valuable prevention strategy.