Geometry, packing, and evolutionary paths to increased multicellular size.

The evolutionary transition to multicellularity transformed life on earth, heralding the evolution of large, complex organisms. Recent experiments demonstrated that laboratory-evolved multicellular "snowflake yeast" readily overcome the physical barriers that limit cluster size by modifying cellular geometry [Jacobeen et al., Nat.

Cellular packing, mechanical stress and the evolution of multicellularity.

The evolution of multicellularity set the stage for sustained increases in organismal complexity. However, a fundamental aspect of this transition remains largely unknown: how do simple clusters of cells evolve increased size when confronted by forces capable of breaking intracellular bonds? Here we show that multicellular snowflake yeast clusters fracture due to crowding-induced mechanical stress. Over seven weeks (~291 generations) of daily selection for large size, snowflake clusters evolve to increase their radius 1.

Impact of post-traumatic hypersomnia on functional recovery of cognition and communication.

Primary Objective: To assess aspects of cognition and communication, in response to the treatment of post-traumatic hypersomnia and mood disturbance.

Research Design: A single case study; pre-post intervention.

Methods And Procedures: The participant was a male with severe TBI and cognitive-communication impairments, who subsequently developed sleep and mood disturbance and excessive daytime sleepiness.

Family caregivers' support needs after brain injury: a synthesis of perspectives from caregivers, programs, and researchers.

There is a dearth of support for family members who assume caregiving responsibilities following acquired brain injury (ABI). This qualitative study broadens the understanding of ABI caregiver support needs through data triangulation from multiple interview sources across different settings. Thirty-nine caregivers across urban and rural settings in Ontario participated in focus groups.

Family interventions after acquired brain injury and other chronic conditions: a critical appraisal of the quality of the evidence.

Family caregivers of individuals with acquired brain injury (ABI) and other chronic disabilities typically experience long-term adjustment difficulties within the entire family system. Interventions to assist parents and spouses are rare, and for siblings and offspring even more so. Among the few existing interventions, only a very small number have been evaluated in any scientifically sound manner for effectiveness in alleviating stress and burden.