Dynactin-dependent cortical dynein and spherical spindle shape correlate temporally with meiotic spindle rotation in Caenorhabditis elegans.

Oocyte meiotic spindles orient with one pole juxtaposed to the cortex to facilitate extrusion of chromosomes into polar bodies. In Caenorhabditis elegans, these acentriolar spindles initially orient parallel to the cortex and then rotate to the perpendicular orientation. To understand the mechanism of spindle rotation, we characterized events that correlated temporally with rotation, including shortening of the spindle in the pole-to pole axis, which resulted in a nearly spherical spindle at rotation. By analyzing large spindles of polyploid C. elegans and a related nematode species, we found that spindle rotation initiated at a defined spherical shape rather than at a defined spindle length. In addition, dynein accumulated on the cortex just before rotation, and microtubules grew from the spindle with plus ends outward during rotation. Dynactin depletion prevented accumulation of dynein on the cortex and prevented spindle rotation independently of effects on spindle shape. These results support a cortical pulling model in which spindle shape might facilitate rotation because a sphere can rotate without deforming the adjacent elastic cytoplasm. We also present evidence that activation of spindle rotation is promoted by dephosphorylation of the basic domain of p150 dynactin

Trust and temporality in participatory research

This paper argues that trust cannot be taken for granted in long-term participatory research and promotes greater consideration to conceptualizing the trusting process as fluid and fragile. This awareness by researchers can reveal to them how the passing of time shapes and reshapes the nature of trusting relationships and their constant negotiation and re-negotiation. The paper draws together literature from different disciplines on the themes of trust, temporality and participatory research and outcomes from interviews and workshops undertaken for The Trust Map project to focus on two key moments that reveal the fragility of trust. These are the subtlety of disruption and trust on trial and trust at a distance. We discuss how trust was built over time through processes of interaction that were continually tested, incremental and participatory

Impairment of Nonverbal Recognition in Alzheimer Disease: A Pet O-15 Study

OBJECTIVE: To characterize deficits in nonverbal recognition memory and functional brain changes associated with these deficits in Alzheimer disease (AD). METHODS: Using O-15 PET, we studied 11 patients with AD and 17 cognitively intact elders during the combined encoding and retrieval periods of a nonverbal recognition task. Both task conditions involved recognition of line drawings of abstract shapes. In both conditions, subjects were first presented a list of shapes as study items, and then a list as test items, containing items from the study list and foils. In the titrated demand condition, the shape study list size (SLS) was adjusted prior to imaging so that each subject performed at approximately 75% recognition accuracy; difficulty during PET scanning in this condition was approximately matched across subjects. A control task was used in which SLS = 1 shape. RESULTS: During performance of the titrated demand condition, SLS averaged 4.55 (+/-1.86) shapes for patients with AD and 7.53 (+/-4.81) for healthy elderly subjects (p = 0.031). However, both groups of subjects were closely matched on performance in the titrated demand condition during PET scanning with 72.17% (+/-7.98%) correct for patients with AD and 72.25% (+/-7.03%) for elders (p = 0.979). PET results demonstrated that patients with AD showed greater mean differences between the titrated demand condition and control in areas including the left fusiform and inferior frontal regions (Brodmann areas 19 and 45). CONCLUSIONS: Relative fusiform and inferior frontal differences may reflect the Alzheimer disease (AD) patients' compensatory engagement of alternate brain regions. The strategy used by patients with AD is likely to be a general mechanism of compensation, rather than task-specific

Community Conversational: Supporting and Capturing Deliberative Talk in Local Consultation Processes

The development of platforms for community decision- making has been of growing interest to the HCI community, yet the ways technology might be woven into traditional consultation processes has been under-studied. We conducted fieldwork at consultation events where residents were invited to discuss and map assets related to their neighbourhoods to inform community decision-making. The fieldwork highlighted problems with equality, turn taking, the evidencing and elaborating on opinions by residents, and challenges related to capturing and documenting the events. We developed Community Conversational—a hybrid table- top game and digital capture and review platform—in response to these issues. Community Conversational was designed to provide a flexible structure to consultation events related to ‘place’, and support the production, capture and review of deliberative ‘talk’ to support decision-making. We study how the platform was used in two consultation events, and discuss the implications of capturing and evidencing local people’s opinions for the accountability of decision- makers and community organisations