Adoption and continued use of mobile contact tracing technology: multilevel explanations from a three-wave panel survey and linked data.

Objective: To identify the key individual-level (demographics, attitudes, mobility) and contextual (COVID-19 case numbers, tiers of mobility restrictions, urban districts) determinants of adopting the NHS COVID-19 contact tracing app and continued use overtime.

Design And Setting: A three-wave panel survey conducted in England in July 2020 (background survey), November 2020 (first measure of app adoption) and March 2021 (continued use of app and new adopters) linked with official data.

Participants: N=2500 adults living in England, representative of England's population in terms of regional distribution, age and gender (2011 census).

Stability patterns and trophic structure in a Delaware Bay plankton community.

Using qualitative loop analysis we have extended our examination of a Delaware Bay plankton community to include an investigation of the roles played by the various entities (population, guild or nutrient) in the community. In an entity removal exercise, we used stability relationships as a probe into community structure. Six types of stability change are possible as a result of entity removal from the system: stable to stable (s-->s); stable to unstable (s-->u); stable to disconnected (s-->d); unstable to stable (u-->s); unstable to unstable (u-->u); unstable to disconnected (u-->d).

Stability-complexity relationships within models of natural systems.

Drawing on the qualitative loop analysis models prepared by Lane for a Delaware Bay plankton community, we evaluated 12 systems that ranged from 14 to 18 entities (population, guild or nutrient). Our approach was to study models of extended trophic biotic communities and examine the stability-complexity issue not only as it exists between systems (the traditional approach) but also with respect to the entities and relationships within a given system. We found no statistically significant inverse relationship for stability and complexity between systems.

The potential for community level evaluations based on loop analysis.

In this paper we present results obtained with a computer simulation in which a community, described by Levins in his presentation of loop analysis (Levins, R., 1975, Evolution in communities near equilibrium, in: Ecology and Evolution of Communities, M.L.

DNA metabolism during infection of Anacystis nidulans by cyanophage AS-1. VII. UV-induced alterations of the AS-1/A. nidulans lytic cycle.

In order to interfere specifically with either the host of phage DNA metabolism and separate the effects of new phage DNA synthesis from the effects of host cell breakdown and PIL-DNA formation, UV irradiation of either the host, A. nidulans, or intact phage AS-1, prior to infection was utilized. Several conclusions were reached.