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Pattern sampling (Whiteside and Williams 1975) was employed to study the population changes, habitats and spatial arrangements (pattern) of littoral cladocera in Lake Itasca, Minnesota during 1974. Population dynamics of the 19 most abundant species of chydorids had changes similar to other populations studied in north—temperate lakes. All species had either spring or fall maxima, or both, a mid—summer low in numbers. Population trends were the same for vegetative and mud habitats. In a comparison of Chara vs. mud habitat we found Chydorus piger, Leydigia leydigi, Alona quadrangularis, Pleuroxus aduncus, and Alona circumfibriata to live mainly in littoral mud. Kruzia latissima, Camptocerus rectirostris and Chydorus faviformis were most restricted to the vegetative habitat, while other species were more ubiquitous. Pielou's (1974) terms describing pattern, phase, mosaic, grain, and intensity are discussed. We redefined intensity as describing the visual effect of density. The changes of intensity accompanying changes in density typified 1974 patterns, while no changes in the other parameters were evident. Preliminary experiments exploring the behavior of chydorids suggest that visual stimuli are very important in directing movements, followed by tactile and chemical clues.

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Motivation: The data that put the ‘evidence’ into ‘evidence-based medicine’ are central to developments in public health, primary and hospital care. A fundamental challenge is to site such data in repositories that can easily be accessed under appropriate technical and governance controls which are effectively audited and are viewed as trustworthy by diverse stakeholders. This demands socio-technical solutions that may easily become enmeshed in protracted debate and controversy as they encounter the norms, values, expectations and concerns of diverse stakeholders. In this context, the development of what are called ‘Data Safe Havens’ has been crucial. Unfortunately, the origins and evolution of the term have led to a range of different definitions being assumed by different groups. There is, however, an intuitively meaningful interpretation that is often assumed by those who have not previously encountered the term: a repository in which useful but potentially sensitive data may be kept securely under governance and informatics systems that are fit-for-purpose and appropriately tailored to the nature of the data being maintained, and may be accessed and utilized by legitimate users undertaking work and research contributing to biomedicine, health and/or to ongoing development of healthcare systems.Results: This review explores a fundamental question: ‘what are the specific criteria that ought reasonably to be met by a data repository if it is to be seen as consistent with this interpretation and viewed as worthy of being accorded the status of ‘Data Safe Haven’ by key stakeholders’? We propose 12 such criteria.Contact: paul.burton@bristol.ac.uk

Current models of protecting human subjects create a zero-sum game of privacy versus data utility. We propose shifting the paradigm to techniques that facilitate trust between researchers and participants.

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Summary1. The wide range in incubation periods among bird species has puzzled biologists for decades, because an extended egg-phase increases time-dependent mortality of the eggs. 2. We investigated a recently proposed mechanistic explanation inspired by life-history theory, suggesting that adults may increase their own survival by reducing nest attentiveness, the percentage of daytime spent incubating eggs, in exchange for reduced offspring (egg) survival due to a longer incubation period. Incubation behaviour and egg temperatures ( T egg ) of 14 bird species in the humid lowland tropics were studied to test the hypothesis that lower nest attentiveness and reduced T egg cause longer incubation periods. 3. Increased nest attentiveness correlated with higher average T egg . However, neither nest attentiveness nor average T egg was associated with the length of the incubation period. Longer off-bouts resulted in lower T egg , but neither number of off-bouts nor off-bout length was associated with incubation period. In addition, we reanalysed a previously published negative association between T egg and incubation period based on literature data from temperate passerine birds using a larger data set and found no significant correlation. 4. In conclusion, our results do not support the hypothesis that longer incubation periods are caused by reduced nest attentiveness and corresponding lower T egg .

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