A Covering Tour Model for Planning Mobile Health Care Facilities in SuhumDistrict, Ghama

The provision of adequate primary health care in developing countries is often troublesome. The problem is to provide a sufficient number of facilities to be geographically accessible, yet few enough to be properly stocked and staffed. In many less developed countries accessibility problems are exacerbated by extensive rainy seasons in which travel is only possible on paved roads. Using the covering tour model we investigate the use of mobile facilities to resolve this dilemma in Suhum District, Ghana. The model minimizes a mobile facility's travel while serving all population centers within range of a feasible stop. Computational results show that in the rainy season the model cannot provide full coverage; over six percent of the population is beyond a covering distance of eight kilometers. In the dry season, 99 percent of the population can be served by a tour at a covering distance of seven kilometers.Beyond a distance of four kilometers, the dry season problem becomes a trade-off between the distance traveled by healthcare patrons and mobile facilities. These results illustrate the importance of flexibility of mobile systems: if accessibility cannot be provided in all seasons it may still be provided at favorable times of the year.     

Recovery of DNA from archaeological insect remains: first results,problems and potential

We report the recovery of short fragments of PCR amplifiable ancient DNA from exoskeletal fragments of the grain weevil Sitophilus granarius (L.) extracted from Roman and medieval deposits in Northern England. If DNA preservation in archaeological insect remains is widespread then many applications in the spheres of evolutionary studies and archaeology can be conceived, some of which are outlined.     

The Linkage of Data Describing Overlapping Geographical Units

Abstract

This article examines advanced ages at death in a historical population in northern Sweden between 1780 and 1900. The source material used is a set of data files from the Demographic Data Base at Umeå University supplemented with the search tool Indiko. The belief that the Sami died at very old ages was tested, and life tables and values of remaining life expectancies at older ages were calculated. The information of the age at death was analysed using a model containing four levels of certainty. The analysis reveals that the Sami did not live to extreme ages. The analysis also reveals large differences between the parishes concerning extreme longevity and correctness of age at death.