Nectar-foraging behavior of Euglossine bees (Hymenoptera: Apidae) in urban areas

Plasmodium of Physarum polycephalum is a single cell visible by unaided eye. During its foraging behavior the cell spans spatially distributed sources of nutrients with a protoplasmic network. Geometrical structure of the protoplasmic networks allows the plasmodium to optimize transfer of nutrients between remote parts of its body, to distributively sense its environment, and make a decentralized decision about further routes of migration. We consider the ten most populated urban areas in United Kingdom and study what would be an optimal layout of transport links between these urban areas from the "plasmodium's point of view". We represent geographical locations of urban areas by oat flakes, inoculate the plasmodium in Greater London area and analyze the plasmodium's foraging behavior. We simulate the behavior of the plasmodium using a particle collective which responds to the environmental conditions to construct and minimize transport networks. Results of our scoping experiments show that during its colonization of the experimental space the plasmodium forms a protoplasmic network isomorphic to a network of major motorways except the motorway linking England with Scotland. We also imitate the reaction of transport network to disastrous events and show how the transport network can be reconfigured during natural or artificial cataclysms. The results of the present research lay a basis for future science of bio-inspired urban and road planning.

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Management of minor ailments in primary schoolchildren in rural and urban areas

Child Care Health and Development ◽

10.1046/j.1365-2214.1996.787787.x ◽

1996 ◽

Vol 22 (3) ◽

pp. 167-174

Author(s):

J A Cantrill ◽

B Johannesson ◽

M Nicholson ◽

P R Noyce

Keyword(s):

Urban Areas ◽

Rural And Urban Areas ◽

Rural And Urban ◽

Primary Schoolchildren ◽

Minor Ailments

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Cannabis use in Switzerland: The role of attribution of drug use to friends, urbanization and repression 1The study was supported by the Swiss Federal Office of Public Health (Bundesamt für Gesundheit BAG) Grant 316.96.5980.

Swiss Journal of Psychology ◽

10.1024//1421-0185.60.2.99 ◽

2001 ◽

Vol 60 (2) ◽

pp. 99-107 ◽

Cited By ~ 7

Author(s):

Holger Schmid

Keyword(s):

Drug Use ◽

Urban Areas ◽

Hierarchical Linear Model ◽

Cannabis Use ◽

School Aged Children ◽

Structural Variables ◽

Hbsc Study ◽

Nationally Representative ◽

Highly Correlated ◽

Individual Use

Cannabis use does not show homogeneous patterns in a country. In particular, urbanization appears to influence prevalence rates, with higher rates in urban areas. A hierarchical linear model (HLM) was employed to analyze these structural influences on individuals in Switzerland. Data for this analysis were taken from the Switzerland survey of Health Behavior in School-Aged Children (HBSC) Study, the most recent survey to assess drug use in a nationally representative sample of 3473 15-year-olds. A total of 1487 male and 1620 female students indicated their cannabis use and their attributions of drug use to friends. As second level variables we included address density in the 26 Swiss Cantons as an indicator of urbanization and officially recorded offences of cannabis use in the Cantons as an indicator of repressive policy. Attribution of drug use to friends is highly correlated with cannabis use. The correlation is even more pronounced in urban Cantons. However, no association between recorded offences and cannabis use was found. The results suggest that structural variables influence individuals. Living in an urban area effects the attribution of drug use to friends. On the other hand repressive policy does not affect individual use.

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