Did they talk their way out of Africa?

Corballis suggests that fully vocal communication was invented by modern humans between 170,000 and 50,000 years ago. Because this new form of communication did not require hand gestures, he wondered whether this may have facilitated the development of lithic manufacture. I cast doubt on this interesting notion but offer an enhanced version that may have more potential.

Sustainable development, rolled-out neoliberalism and sustainable communities

Recent contributions by geographers on the relationships between states and citizens have documented the rise of rolled-out neoliberalism. Development agendas are, it is argued, increasingly dominated by the principles of market-driven reforms, social inequality, and a drive towards enhancing the economic competitiveness of the supply side of the economy. However, at the same time, a parallel set of discourses has emerged in the development literature which argues that it is principles of sustainable development that have, in practice, become dominant. The emphasis is, instead, on democratic empowerment, environmental conservation, and social justice. This paper examines the relationships between these ostensibly very different interpretations of contemporary development with an assessment of one of the Labour government's most ambitious planning agendas-the publication in February 2003 of the document Sustainable Communities: Building for the Future. The proposals are promoted as a "step change" in the planning system with a new emphasis on tackling shortages of housing in the South East and reviving the economy of the Thames Gateway area. The paper assesses the different ways in which such programmes can be interpreted and argues that contemporary development practices in countries such as Britain are constituted by a hybridity of approaches and rationalities and cannot be reduced to simple characterisations of rolled-out neoliberalism or sustainable development.

Self-activation and out-group contrast

It has been suggested that higher in-group identifiers primed with an out-group stereotype show contrastive behavioral responses because they activate the in-group, social-self. However, priming the personal-self can lead to contrastive judgments. We investigated whether personal self-activation was also evident for higher identifiers primed with an out-group. An experiment demonstrated that higher identifiers primed with an out-group showed faster responses to self-words than higher identifiers primed with the in-group. This findings suggest that the personal-self is also activated for higher identifiers primed with an out-group, and this self-activation may underlie their contrastive responding.

Environmental control for layers

Light patterns have less effect on numbers of eggs laid by current stocks than on those of forty years ago, but the principles have not changed. Ovarian activity is stimulated by increasing photoperiods and suppressed by decreasing photoperiods. The light pattern used during rearing can still have large effects on age at 50% lay, even for modern stocks. Early sexual maturity maximises egg numbers but gives smaller eggs. Late maturity maximises egg size at the expense of numbers. The relationship between egg output (g/hen d) and age at first egg is curvilinear, with maximum yield occurring in flocks maturing in about the centre of their potential range. Fancy patterns of increasing daylength after maturity are probably not justified. A flock held on a constant 14h day will lay as many eggs as one given step up lighting. Intermittent lighting saves about 5% of feed consumption with no loss of output, provided that the feed has adequate amino acid content to allow for the reduced feed intake. Producers with light-proof laying houses should be taking advantage of intermittent lighting. The recommended light intensity for laying houses is still 10 lx, although the physiological threshold for response to changes in photoperiod is closer to 2 lx. Very dim (0.05 lx) light filtering into blacked out houses will not stimulate the hypothalamic receptors responsible for photo-sexual responses, but may affect the bird's biological clock, which can alter its response to a constant short photoperiod. Feed intake shows a curvilinear dependence on environmental temperature. At temperatures below the panting threshold, performance can be maintained by adjusting the feed so as to maintain an adequate intake of critical amino acids. Above the panting threshold, the hen is unable to take in enough energy to maintain normal output. There is no dietary modification which can effectively offset this problem. Diurnally cycling temperatures result in feed intake and egg production equivalent to that observed under a constant temperature equal to the mean of the cycle. When the poultry house is cooler at night than by day, it helps to provide light so that the birds can feed during the cooler part of the cycle.