ASSESSMENTS AND DECISIONS IN METELLINA-SEGMENTATA (ARANEAE, METIDAE) - EVIDENCE OF A PHEROMONE INVOLVED IN MATE GUARDING

Assessments and decision-making underlying the initiation of mate guarding in a common web-building spider, Metellina segmentata, are examined in a series of field and laboratory studies. Adult males do not build webs but wander in search of females and mating opportunities. Adult males then wait at the edge of the webs of females and guard them prior to courtship and mating. Guarded females were heavier, larger and carried more mature eggs than solitary females. An active process of information gathering is apparent from introductions of males to the webs of females. Males make accurate assessments about female quality, even in the absence of the resident female. Cues involving web architecture are not used. Males may assess pheromonal cues on the web of the female in deciding whether to guard or abandon a female.

On the Qualitative Comparison of Decisions Having Positive and Negative Features

Making a decision is often a matter of listing and comparing positive and negative arguments. In such cases, the evaluation scale for decisions should be considered bipolar, that is, negative and positive values should be explicitly distinguished. That is what is done, for example, in Cumulative Prospect Theory. However, contrary to the latter framework that presupposes genuine numerical assessments, human agents often decide on the basis of an ordinal ranking of the pros and the cons, and by focusing on the most salient arguments. In other terms, the decision process is qualitative as well as bipolar. In this article, based on a bipolar extension of possibility theory, we define and axiomatically characterize several decision rules tailored for the joint handling of positive and negative arguments in an ordinal setting. The simplest rules can be viewed as extensions of the maximin and maximax criteria to the bipolar case, and consequently suffer from poor decisive power. More decisive rules that refine the former are also proposed. These refinements agree both with principles of efficiency and with the spirit of order-of-magnitude reasoning, that prevails in qualitative decision theory. The most refined decision rule uses leximin rankings of the pros and the cons, and the ideas of counting arguments of equal strength and cancelling pros by cons. It is shown to come down to a special case of Cumulative Prospect Theory, and to subsume the “Take the Best” heuristic studied by cognitive psychologists.

Who makes prescribing decisions in hospital inpatients?:An observational study

Errors involving drug prescriptions are a key target for patient safety initiatives. Recent studies have focused on error rates across different grades of doctors in order to target interventions. However, many prescriptions are not instigated by the doctor who writes them. It is important to clarify how often this occurs in order to interpret these studies and create interventions. This study aimed to provisionally quantify and describe prescriptions where the identity of the decision maker and prescription writer differed.

Energy: lessons from devolution

Geraint Ellis and Richard Cowell explain the findings of the ‘Delivering renewable energy under devolution’ project, including some reasons for Scotland’s lead.

The UK has seen massive increases in renewable energy since 1998, with installed capacity growing from 2,600 MW to 12,300 MW in 2011. This has coincided with devolution and it is within Northern Ireland, Scotland and Wales that the greatest increases have been seen.

As devolved administrations now host half of the UK’s renewable energy capacity, their policies are critical to achieving the broader UK targets. This also provides a fascinating insight into what sort of approach works best, and why. This has been the focus of a two-year study, funded by the Economic and Social Research Council, involving universities from across the UK, which indicates that Scotland is leading the way on renewable energy.

All devolved governments have offered significant support to renewable energy but have different degrees of powers in relation to energy. Scotland’s success seems to be based on the centrality of energy issues to current political aspirations, particularly the SNP, but also has cross-party support. The research suggests that the consensus on the importance of renewable energy amongst élite interests in Scotland helps to explain why Scottish governments have been empowered and enabled to make robust use of the powers available.

As it has achieved successful growth in the sector, this too helps cultivate credibility among key business interests and gives increased leverage to its position in policy discussions with the UK Government. Scotland has been more consistent over time in presenting the expansion of renewable energy as a national economic agenda, rather than just an environmental or rural development agenda. The availability of larger, windy, but relatively less contested sites for onshore wind in Scotland has meant that more projects went through central consenting procedures rather than local planning authorities. Its enhanced support for wave and tidal power technologies is also notable. These political conditions have been harder to find in the rest of the UK, making progress a little more uncertain.

Northern Ireland has used its powers (which are more extensive than Scotland’s) to facilitate small-scale renewables and bio-fuel processes, with its liberalised planning regime offering an initial boost to expanding capacity.

This has contrasted with the position in Wales, which has least control over energy but the Welsh Government has adopted a more innovative approach to strategic spatial zoning; this appears to have pulled in a larger volume of onshore wind development interest than could be expected in a comparable region of England. A downside of the Welsh approach appears to be the fact that the concentration of these wind projects in these zones has triggered public opposition and political conflict.

It therefore appears that the powers available to the devolved governments do not seem to determine which country has been able to make greatest headway, with broader political commitments being more significant. Despite this, the research does not conclude that the actions and activities undertaken by the devolved governments are necessarily the most important factors in shaping the development of renewable energy in the UK. This is because devolution is still a relatively new dimension of energy governance in the UK and decisions affecting key drivers for renewable energy investment are still made mainly in Westminster, with the Treasury exercising close budgetary control. In all areas of the UK, grid capacity expansion remains slow to achieve. The major growth in offshore wind to date has been driven mainly by Westminster and cross-UK bodies with the most significant capacity growth being in English territorial waters.