Rats cannot have been intermediate hosts for Yersinia pestis during medieval plague epidemics in Northern Europe

The commonly accepted understanding of modern human plague epidemics has been that plague is a disease of rodents that is transmitted to humans from black rats, with rat fleas as vectors. Historians have assumed that this transmission model is also valid for the Black Death and later medieval plague epidemics in Europe. Here we examine information on the geographical distribution and population density of the black rat (Rattus rattus) in Norway and other Nordic countries in medieval times. The study is based on older zoological literature and on bone samples from archaeological excavations. Only a few of the archaeological finds from medieval harbour towns in Norway contain rat bones. There are no finds of black rats from the many archaeological excavations in rural areas or from the inland town of Hamar. These results show that it is extremely unlikely that rats accounted for the spread of plague to rural areas in Norway. Archaeological evidence from other Nordic countries indicates that rats were uncommon there too, and were therefore unlikely to be responsible for the dissemination of human plague. We hypothesize that the mode of transmission during the historical plague epidemics was from human to human via an insect ectoparasite vector.     

Rational Goals for the Urban Environment: A Swedish Example

In Sweden, the government's aim to create sustainable urban environments is expressed through the environmental quality objective “A good built environment”. The objective embraces seven sub-goals and is designed to guide central, regional and local authorities’ planning towards urban sustainability. However, for objectives concerning the urban environment, such as the Swedish objective “A good built environment”, to form a solid basis for decision-making, two types of rationality (functionality) conditions ought to be met. First, the objectives should guide and motivate those who are responsible for their implementation. This is applicable when the goals satisfy the criteria of precision, evaluability, approachability and motivity. Second, when the goals are parts of larger goal systems, the goal systems should be coherent. Using the objective “A good built environment” as an empirical basis, this article gives a few examples of how environmental goals can fail to guide and motivate action towards improved urban sustainability.     

Early medieval origins of iron mining and settlement in central Sweden: multiproxy analysis of sediment and peat records from the Norberg mining district

The historical Norberg mining district in central Sweden with its shallow, easily accessible iron ores figures prominently in the earliest documents from the 14th century concerning mining or metallurgy. This 1000-km² district is considered to be one of the first areas in Sweden exploited for iron ores and, in fact, Europe’s oldest known blast furnace, Lapphyttan, is located in the Norberg district about 10 km from the mines in the village of Norberg (Norbergsby). Earlier archaeological excavations suggest the furnace was in operation as early as the 11th or 12th century (870 and 930 ¹⁴C yr BP), and a number of other sites in the district have been dated to the 13th–15th centuries. Here, we have analyzed two lake sediment records (Kalven and Noren) from the village of Norberg and a peat record from Lapphyttan. The Lapphyttan peat record was radiocarbon dated, whereas the sediment from Kalven is annually laminated, which provides a fairly precise chronology. Our pollen data indicate that land use in the area began gradually as forest grazing by at least c. AD 1050, with indications of more widespread forest disturbance and cultivation from c. 1180 at Lapphyttan and 1250 at Kalven. Based on ²⁰⁶Pb/²⁰⁷Pb isotope ratios in Kalven’s varved sediment record, there is an indication of mining or metallurgy in the area c. 960, but likely not in immediate connection to our sites. Evidence of mining and metallurgy increases gradually from c. 1180 when there is a decline in ²⁰⁶Pb/²⁰⁷Pb ratios and an increase in charcoal particles at Lapphyttan, followed by increasing inputs of lithogenic elements in Noren’s sediment record indicating soil disturbance, which we attribute to the onset of mining the iron ore bodies surrounding Noren. From AD 1295 onwards evidence of mining and metallurgy are ubiquitous, and activities accelerate especially during the late 15th century; the maximum influence of Bergslagen ore lead (i.e., the minimum in ²⁰⁶Pb/²⁰⁷Pb isotope ratios) in both Kalven and Noren occurs c. 1490–1500, when also varve properties change in Kalven and in Noren sharp increases occur in the concentrations of a range of other ore-related metals (e.g., arsenic, cadmium, copper, iron, lead, mercury and zinc). From the 15th century onwards mining and metallurgy are the dominant feature of the sediment records.     

Climate in the eastern Mediterranean,and adjacent regions,during the past 6000 years – A review

The eastern Mediterranean, with its long archaeological and historical records, provides a unique opportunity to study human responses to climate variability. We review paleoclimate data and reconstructions from the region with a focus on the last 6000 years. We aim to provide an up-to-date source of information on climate variability and to outline present limitations and future opportunities. The review work is threefold: (1) literature review, (2) spatial and temporal analysis of proxy records, and (3) statistical estimation of uncertainties in present paleoclimate reconstructions (temperature, °C). On a regional scale the review reveals a wetter situation from 6000 to 5400 yrs BP (note: all ages in this paper are in calibrated years before present (i.e. before 1950), abbreviated yrs BP, unless otherwise stated). This is followed by a less wet period leading up to one of fully-developed aridity from c. 4600 yrs BP. There is a need for more high-resolution paleoclimate records, in order to (i) better understand regional patterns and trends versus local climate variability and to (ii) fill the gap of data from some regions, such as the Near East, Greece and Egypt. Further, we evaluate the regional occurrence of a proposed widespread climate event at 4200 yrs BP. This proposed climate anomaly has been used to explain profound changes in human societies at different locations in the region around this time. We suggest that although aridity was widespread around 4200 yrs BP in the eastern Mediterranean region, there is not enough evidence to support the notion of a climate event with rapidly drying conditions in this region.