På terskelen til den «levende natur» – landskapsarkitekten Knut Ove Hillestads virke i NVE 1963–1990
- Side: 71-92
- Publisert på Idunn: 2010-04-13
- Publisert: 2010-04-13
Den norske landskapsarkitekten Knut Ove Hillestad var ansatt ved Norges Vassdrags- og Elektrisitetsvesen, NVE, i årene 1963–1991. I denne perioden ledet han utformingen av landskap etter vassdragsutbygging. Hans rettesnor for denne virksomheten var å etterlate såkalt «levende natur», natur som hadde vært utsatt for menneskelige inngrep, men som var artsrik og reproduktiv. Artikkelen vil ta for seg hvordan denne tankegangen ble til, hvordan den ble utbredt og hvordan den ble institusjonalisert. Et sentralt tema i den forbindelse er Hillestads overgang fra å være utøver av én profesjon til å koordinere en prosjektorganisasjon, hvor mange logikker skulle forenes.
Were medieval plagues the same disease as modern plague?
In his book The Black Death Transformed, the historian Samuel Cohn claims that the epidemic disease described in Western European historical sources from AD 1347 to the mid-17th century under the name pestis and similar terms must have been a disease other than the modern plague that reached Hong Kong in 1894. The disease was shown to be caused by the bacterium Yersinia pestis, and, some years later, the most likely transmission route was found to be from the black rat to humans via the rat flea Xenopsylla cheopis. Cohns main arguments are that: 1) there is a complete lack of evidence of the involvement of rats and rat fleas in late-medieval/early-modern plagues, and 2) the speed of transmission is different. Medieval plagues spread rapidly, whereas the spread of modern plague has been slow. However, during the past ten years scientists have found traces of Yersinia pestis DNA in dental pulp from medieval plague victims. It has also recently been shown that fleas other than Xenopsylla cheopis can be efficient transmitters of plague. The obvious candidate in all northern European countries is the human flea Pulex irritans, which in earlier times could be found in large numbers, and not just in beds, but also in thick layers of clothing. This has led to the conclusion that: 1) most or all late medieval and early modern «plague» epidemics were caused by Yersinia pestis, 2) few if any of the historical European plague epidemics involved rats as intermediate host. The mode of transmission was from human to human via an insect vector. Pulex irritans may have been the most important arthropod vector in Europe prior to the late 19th century, but other ectoparasites (other fleas, lice, etc.) could also have been involved.