Is big best? Queen size, usurpation and nest closure in a primitively eusocial sweat bee (Lasioglossum malachurum).

For primitively eusocial insects in which a single foundress establishes a nest at the start of the colony cycle, the solitary provisioning phase before first worker emergence represents a risky period when other, nestless foundresses may attempt to usurp the nest. In the primitively eusocial sweat bee Lasioglossum malachurum (Hymenoptera, Halictidae), spring foundresses compete for nests which are dug into hard soil. Nest-searching foundresses (‘floaters’) frequently inspected nests during this solitary phase and thereby exerted a usurpation pressure on resident queens. Usurpation has been hypothesised to increase across the solitary provisioning phase and favour closure of nests at an aggregation, marking the termination of the solitary provisioning phase by foundresses, before worker emergence. However, our experimental and observational data suggest that usurpation pressure may remain constant or even decrease across the solitary provisioning phase and therefore cannot explain nest closure before first worker emergence. Levels of aggression during encounters between residents and floaters were surprisingly low (9% of encounters across 2 years), and the outcome of confrontations was in favour of residents (resident maintains residency in 94% of encounters across 2 years). Residents were significantly larger than floaters. However, the relationship between queen size and offspring production, though positive, was not statistically significant. Size therefore seems to confer a considerable advantage to a queen during the solitary provisioning phase in terms of nest residency, but its importance in terms of worker production appears marginal. Factors other than intraspecific usurpation need to be invoked to explain the break in provisioning activity of a foundress before first worker emergence.

A numerical approach to C-14 wiggle-match dating of organic deposits: best fits and confidence intervals

14C wiggle-match dating (WMD) of peat deposits uses the non-linear relationship between 14C age and calendar age to match the shape of a sequence of closely spaced peat 14C dates with the 14C calibration curve. A numerical approach to WMD enables the quantitative assessment of various possible wiggle-match solutions and of calendar year confidence intervals for sequences of 14C dates. We assess the assumptions, advantages, and limitations of the method. Several case-studies show that WMD results in more precise chronologies than when individual 14C dates are calibrated. WMD is most successful during periods with major excursions in the 14C calibration curve (e.g., in one case WMD could narrow down confidence intervals from 230 to 36 yr).

Breast is Best? Reasons Why Mothers Decide to Breastfeed or Bottlefeed their Babies and Factors Influencing the Duration of Breastfeeding.

Breastfeeding is known to confer benefits, both in the short term and long term, to the child and also to the mother. Various health-promotion initiatives have aimed to increase breastfeeding rates and duration in the United Kingdom over the past decade. In order to assist in these endeavours, it is essential to understand the reasons why women decide whether to breastfeed and the factors that influence the duration of breastfeeding. This study reports breastfeeding initiation and duration rates of mothers participating in the Growth, Learning and Development study undertaken by the Child Health & Welfare Recognised Research Group. Although this study cannot provide prevalence data for all mothers in Greater Belfast, it can provide useful information on trends within particular groups of the population. In addition, it examines maternally reported reasons for choosing to breastfeed and for breastfeeding cessation. The likelihood of mothers initiating breastfeeding is influenced by factors such as increased age, higher educational attainment and higher socio-economic grouping. The most common reason cited for breastfeeding is that it is “best for baby”. Returning to work is the most important factor in influencing whether mothers continued to breastfeed. Women report different reasons for cessation depending on the age of their child when they stopped breastfeeding. This information should inform health-promotion initiatives and interventions.

The postmodernist war on evidence-based practice

In this paper, we examine the war of words between those who contend that health care practice, including nursing, should primarily be informed by research (the evidence-based practice movement), and those who argue that there should be no restrictions on the sources of knowledge used by practitioners (the postmodernists). We review the postmodernist interventions of Dave Holmes and his colleagues, observing that the postmodernist style to which they adhere, which includes the use of continental philosophy, metaphors, and acerbic delivery, tends to obscure their substantive arguments. The heated nature of some responses to them has tended to have the same effect. However, the substantive arguments are important. Five main postmodernist charges are identified and discussed. The first argument, that the notion of ‘best evidence’ implies a hierarchical and exclusivist approach to knowledge, is persuasive. However, the contention that this hierarchy is maintained by the combined pressures of capitalism and vested interests within academia and the health services, is less well founded. Nevertheless, postmodernist contentions that the hierarchy embraced by the evidence-based practice movement damages health care because it excludes other forms of evidence that are needed to understand the complexity of care, it marginalizes important aspects of clinical knowledge, and it fails to take account of individuals or their experience, are all seen to be of some merit. However, we do not share the postmodernist conclusion that this adds up to a fascist order. Instead, we characterize evidence-based practice as a necessary but not sufficient component of health care knowledge.

Best of the old alongside the new: training for part-time youth workers

Set against the dearth of published research into the effectiveness of youth leadership training programmes, the present study describes how a comprehensive evaluation model was utilised to evaluate one such programme in Northern Ireland over a 3-year period. The training welds together a traditional curriculum approach and a competence-based methodology to provide an integrated experience for the part-time youth worker participants (n = 128). Self-completion questionnaires and follow-up interviews with a random sample of these youth workers and their supervisors were used to collect data. Outcomes suggest that the synthesis of these two training strategies is not only effective in meeting the learning needs of youth workers, but also leads to identifiable improvements in the range and quality of youth work programmes available to young people