DYMOND: DYnamic MOtif-NoDes Network Generative Model

Motifs, which have been established as building blocks for network structure, move beyond pair-wise connections to capture longer-range correlations in connections and activity. In spite of this, there are few generative graph models that consider higher-order network structures and even fewer that focus on using motifs in models of dynamic graphs. Most existing generative models for temporal graphs strictly grow the networks via edge addition, and the models are evaluated using static graph structure metrics -- which do not adequately capture the temporal behavior of the network. To address these issues, in this work we propose DYnamic MOtif-NoDes (DYMOND) -- a generative model that considers (i) the dynamic changes in overall graph structure using temporal motif activity and (ii) the roles nodes play in motifs (e.g., one node plays the hub role in a wedge, while the remaining two act as spokes). We compare DYMOND to three dynamic graph generative model baselines on real-world networks and show that DYMOND performs better at generating graph structure and node behavior similar to the observed network. We also propose a new methodology to adapt graph structure metrics to better evaluate the temporal aspect of the network. These metrics take into account the changes in overall graph structure and the individual nodes' behavior over time.Comment: In Proceedings of the Web Conference 2021 (WWW '21

Team Cognition for Coordinated Decision-Making during Hurricane Harvey: A Case Study from Interviews with Responding Commanders

PresentationTo protect and assist threatened populations and infrastructures in response to natural and man- made disasters, emergency responders from diverse backgrounds collectively work as ad hoc teams. However, responders’ coordinated decision-making in real-time has not been adequately addressed in terms of team cognition. Here team cognition is a binding mechanism that produces coordinated behaviors among responders (adapted from Fiore & Salas, 2004). We are particularly interested in cognition of an incident management team (IMT), an ad hoc strategic decision-making team of command-level responders co-located at the incident command post of major incidents such as Hurricane Harvey. To develop and provide an incident action plan to subordinate branch directors in the field, an IMT continuously manages information based on incoming cues from outside, following a cyclical planning process. Interestingly, an IMT is a team of functional sub-teams, and each sub-team is also a team of functional units. The purpose of this on-going case study is to investigate the role of team cognition for coordinated real-time decision-making in emergency response, through a case study of a recent disaster, Hurricane Harvey. During the interviews with subject matter experts (SMEs, i.e., responding commanders worked during Hurricane Harvey), we asked how responding commanders as a cognitive system-of-systems (or a team-of-teams) continuously made coordinated decisions, especially in terms of communication and information management. In a prior work, a P∙D∙A (Perceive∙Diagnose∙Adapt) model, a theoretical interactionist model of team cognition in emergency response, was proposed as a proof-of-concept that depicts nonlinear, interdependent, and dynamic interactions observed within and among three functional sub-teams of a planning team of an IMT at a simulated incident command post (Moon, Son, Sasangohar, Peres, & Neville, 2018). Through interviews with SMEs, this case study is expected to validate the P∙D∙A model

Predictors of Hospital Readmissions for People with Chronic Conditions

Background: Hospital readmissions remain prominent in health care. Functional, cognitive, and environmental factors predict hospital readmissions but may not be thoroughly measured or addressed prior to discharge. Method: In this cross-sectional study, people hospitalized with chronic conditions completed measures of self-care function, functional cognition, occupational competence, and environmental impact. They also participated in a phone call or medical records review to identify hospital readmissions within 30 days of discharge. In a group session, occupational therapists who work in acute care completed acceptability, appropriateness, and feasibility measures for the standardized assessments administered to hospital participants. Results: Occupational competence and functional cognition were significant predictors of hospital readmissions. Therapists rated the Activity Measure of Post-Acute Care (AM-PAC) as the most acceptable, appropriate, and feasible measure for acute care. Conclusions: Occupational competence and functional cognition are predictors of hospital readmissions in people with chronic conditions. Occupational therapists in acute care should consider supplementing current evaluation practices with standardized measures of functional cognition and occupational competence to identify client needs objectively and initiate post-acute referrals that help clients discharge home successfully. Standardized measures, such as the AM-PAC may be feasible in acute care. Further research on the efficacy of standardized measures in this setting is needed

Predictors of Occupational Competence in People Hospitalized with Chronic Conditions

Background: Chronic diseases limit participation in meaningful daily activities, roles, and routines, which can negatively impact occupational competence, a sense of self, and life satisfaction, especially when hospitalization is required to manage disease symptoms. Standardized measures of occupational competence and related functional, cognitive, and environmental factors may enhance occupational therapists’ ability to identify potential barriers to and make targeted recommendations for self- and health management in the community. Method: This cross-sectional study investigated occupational competence in patients hospitalized with chronic conditions. The participants completed measures of occupational competence, values, self-care function, environmental impact, and functional cognition while hospitalized. Results: The participants (n = 51) reported moderate to high levels of occupational competence. The overall regression model was significant. Values, self-care function, and environmental impact were significant predictors of occupational competence. Conclusion: Values, self-care function, and environmental impact predict occupational competence in people hospitalized with chronic conditions. Occupational therapists should incorporate standardized measures of occupational competence, values, self-care function, and environmental impact into current evaluation practices to support recommendations for follow-up care and community supports. Future research should include a larger sample that is more representative of an occupational therapy caseload and incorporate alternative measures of functional cognition to better measure this construct

Two-Stage Passive Vibration Isolator

The design and testing of a structural system were implemented to hold the optics of the planned Space Interferometry Mission (SIM) at positions and orientations characterized by vibrational translation and rotation errors of no more than a few nanometers or a few milliarcseconds, respectively. Much of the effort was devoted to a test bed for verifying the predicted behavior of a vibration- isolation structural subsystem working together with an active control system for positioning and orienting the SIM optics. There was considerable emphasis on the vibration-isolation subsystem, which was passive and comprised two stages. The main sources of vibration were six reaction wheels in an assembly denoted the "backpack." The first vibration-isolation stage consisted of hexapod isolator mounts - one for each reaction wheel - characterized by a natural vibration frequency of 10 Hz. The second stage was a set of three beams, disposed between the backpack and the structure that held the SIM optics, that were flexured such that they transmitted only bending loads, with a natural vibrational frequency and damping of about 5 Hz and 4 percent, respectively. Preliminary test results were presented and characterized as demonstrating the effectiveness of the two-stage vibration-isolation design

Long-term trends in invertebrate-habitat relationships under protected and fished conditions

Few studies examine the long-term effects of changing predator size and abundance on the habitat associations of resident organisms despite that this knowledge is critical to understand the ecosystem effects of fishing. Marine reserves offer the opportunity to determine ecosystem-level effects of manipulated predator densities, while parallel monitoring of adjacent fished areas allows separating these effects from regional-scale change. Relationships between two measures of benthic habitat structure (reef architecture and topographic complexity) and key invertebrate species were followed over 17years at fished and protected subtidal rocky reefs associated with two southern Australian marine reserves. Two commercially harvested species, the southern rock lobster (Jasus edwardsii) and blacklip abalone (Haliotis rubra) were initially weakly associated with habitat structure across all fished and protected sites. The strength of association with habitat for both species increased markedly at protected sites 2years after marine reserve declaration, and then gradually weakened over subsequent years. The increasing size of rock lobster within reserves apparently reduced their dependency on reef shelters as refuges from predation. Rising predation by fish and rock lobster in the reserves corresponded with weakening invertebrate-habitat relationships for H. rubra and sea urchins (Heliocidaris erythrogramma). These results emphasise that animal-habitat relationships are not necessarily stable through time and highlight the value of marine reserves as reference sites. Our work shows that fishery closures to enhance populations of commercially important and keystone species should be in areas with a range of habitat features to accommodate shifting ecological requirements with ontogenesis

Beam tests of a large-scale TORCH time-of-flight demonstrator

The TORCH time-of-flight detector is designed to provide particle identification in the momentum range 2-10 GeV/c over large areas. The detector exploits prompt Cherenkov light produced by charged particles traversing a 10 mm thick quartz plate. The photons propagate via total internal reflection and are focused onto a detector plane comprising position-sensitive Micro-Channel Plate Photo-Multiplier Tubes (MCP-PMT) detectors. The goal is to achieve a single-photon timing resolution of 70 ps, giving a timing precision of 15 ps per charged particle by combining the information from around 30 detected photons. The MCP-PMT detectors have been developed with a commercial partner (Photek Ltd, UK), leading to the delivery of a square tube of active area 53 $\times$ 53mm$^2$ with a granularity of 8 $\times$ 128 pixels equivalent. A large-scale demonstrator of TORCH, having a quartz plate of dimensions 660 $\times$ 1250 $\times$ 10 mm$^3$ and read out by a pair of MCP-PMTs with custom readout electronics, has been verified in a test beam campaign at the CERN PS. Preliminary results indicate that the required performance is close to being achieved. The anticipated performance of a full-scale TORCH detector at the LHCb experiment is presented.Comment: 12 pages, 7 figures, Paper submitted to Nuclear Instruments & Methods in Physics Research, Section A - Special Issue VCI 201