The Even and Odd Supersymmetric Hunter - Saxton and Liouville Equations

It is shown that two different supersymmetric extensions of the Harry Dym equation lead to two different negative hierarchies of the supersymmetric integrable equations. While the first one yields the known even supersymmetric Hunter - Saxton equation, the second one is a new odd supersymmetric Hunter - Saxton equation. It is further proved that these two supersymmetric extensions of the Hunter - Saxton equation are reciprocally transformed to two different supersymmetric extensions of the Liouville equation.Comment: typos corrected and references added. To appear in Phys.Lett

Target-searching on the percolation

We study target-searching processes on a percolation, on which a hunter tracks a target by smelling odors it emits. The odor intensity is supposed to be inversely proportional to the distance it propagates. The Monte Carlo simulation is performed on a 2-dimensional bond-percolation above the threshold. Having no idea of the location of the target, the hunter determines its moves only by random attempts in each direction. For lager percolation connectivity $p\gtrsim 0.90$, it reveals a scaling law for the searching time versus the distance to the position of the target. The scaling exponent is dependent on the sensitivity of the hunter. For smaller $p$, the scaling law is broken and the probability of finding out the target significantly reduces. The hunter seems trapped in the cluster of the percolation and can hardly reach the goal.Comment: 5 figure

Firewood, food and niche construction : the potential role of Mesolithic hunter-gatherers in actively structuring Scotland's woodlands.

Over the past few decades the potential role of Mesolithic hunter–gatherers in actively constructing their own niches, through the management of wild plants, has frequently been discussed. It is probable that Mesolithic hunter–gatherers systematically exploited specific woodland resources for food and fuel and influenced the ‘natural’ abundance or distribution of particular species within Mesolithic environments. Though there has been considerable discussion of the pollen evidence for potential small-scale human-woodland manipulation in Mesolithic Scotland, the archaeobotanical evidence for anthropogenic firewood and food selection has not been discussed in this context. This paper assesses the evidence for the active role of Mesolithic hunter–gatherer communities in systematically exploiting and managing woodlands for food and fuel in Scotland. While taphonomic factors may have impacted on the frequency of specific species in archaeobotanical assemblages, it is suggested that hunter–gatherers in Mesolithic Scotland were systematically using woodland plants, and in particular hazel and oak, for food and fuel. It is argued that the pollen evidence for woodland management is equivocal, but hints at the role of hunter–gatherers in shaping the structure of their environments, through the maintenance or creation of woodland clearings for settlement or as part of vegetation management strategies. It is proposed that Mesolithic hunter–gatherers may have actively contributed to niche construction and that the systematic use of hazel and oak as a fuel may reflect the deliberate pruning of hazel trees to increase nut-yields and the inadvertent – or perhaps deliberate – coppicing of hazel and oak during greenwood collection

WHY CAN HUNTER-GATHERER GROUPS BE ORGANIZED SIMLARLY FOR RESOURCE PROCUREMENT, BUT THEIR KINSHIP TERMINOLOGIES ARE STRIKINGLY DISSIMILAR: A CHALLENGE FOR FUTURE CROSS-CULTURAL RESEARCH

Cross-cultural research involves explanatory arguments framed at the meta-level of a cohort of societies, each with its own historical development as an internally structured and organized system. Historically, cross-cultural research on hunter-gatherer groups initially was in accord with the general anthropological interest in determining the ideational basis for differences in systems of social organization, but more recent work has shifted emphasis to the phenomenal level of factors affecting the mode of adaptation to an external environment. This has left a major lacuna in our understanding of the reasons for cross-cultural differences among ideational systems such as kinship terminologies in hunter-gatherer societies. I address this lacuna in this article through cross-cultural comparison of hunter-gatherer kinship terminologies at an ideational, qualitative level. The means for so doing is first worked out using the kinship terminology of the Hadza, an East African hunter-gather group. Next, comparison of the Hadza and their kinship terminology with two other hunter-gatherer groups prominent in the anthropological literature, along with their kinship terminologies, makes evident a major disjunction between, on the one hand, the similarity of hunter-gatherer societies at the phenomenal level of activities such as food procurement and, on the other hand, striking differences among the same groups at the ideational level of the structural organization of their kinship terminologies. The reason for the striking differences between the ideational and the phenomenal levels is not immediately evident and remains a topic to be addressed in future cross-cultural research