The community sample is made up
The Human HGF / Hepatocyte Growth Factor Protein sample is made up of 45 randomly selected compounds in occupied lands belonging to the Tangaltong clan. This clan was chosen for the sample population because its families were the earliest to settle in the area first occupied by the community in the Tangale hills (Gwani, 1999); it is also the only clan sub-divided into two sub-clans, making it more complex in social organization compared with the other clans. It therefore comprises the most number of families, totaling 29 . These families are spread across three urban towns (Billiri, Bare, and Komta) and surrounding village settlements (Kure, 1987; Mela, 2004). Billiri serves as the administrative headquarters of the local government area (LGA) and the location of the government-provided prototype units. The first set of prototype units, Pro I, consists of 20 single-bedroom duplex bungalows situated a few meters away from A345. The concrete units, constructed in the 1980s, are part of a national housing scheme implemented in most of the LGAs of Nigeria. These were not occupied by the Tangale community and remain abandoned. The second set of units (Pro II) is also constructed in concrete, and consists of three-bedroom bungalows with servants\' quarters at the rear. These are found in some towns across the north east region of Nigeria. Four of such houses were constructed in Billiri, also along A345 (Fig. 1). Three of these units were abandoned and left unoccupied, whereas one was modified and occupied (Pro II mod).
Discussion and implication of findings
Recommendations for further research
Introduction The Sahara, from the Neolithic era, has always been an area of great change. Man has adapted and persisted through the centuries to guarantee its survival within the climatic constraints of southern Algeria. The climate has been the foremost environmental factor that influenced the evolution of vernacular settlements and building design. It is well known that southern Algeria is one of the most arid lands of the world. The prevailing outdoor environmental conditions that influence inhabitants comfort are mainly of four types: high temperatures and intense solar radiation; high glare from direct and reflected sunlight; dust storms, mainly in the afternoons; in some regions with cold winters, cold winds in the winter season; low annual rainfall, torrential rain causing severe floods. In general the south of Algeria has a typical desert climate with variations between seasons and between day and night temperatures. The climate is hot and dry during the summer with cold nights and mild days during the winter. The rainfall occurs mainly in winter (few days per year) and the relative humidity is low especially during the summer. Wind is the main factor for the desert topography. Sandstorms occur during certain times of the year, usually in March and April. Regarding the Sirocco, it occurs at an average of 10 days/year during the period from May to September months. Protection against the devastating effects of wind on the inhabitants has become a major problem to deal with. The use of screens and obstacles is one of responses. Under these harsh conditions and inhospitable surroundings the vernacular settlements survive using passive means to provide comfort of inhabitants as demonstrated by Bouchair and Dupagne (2003) and Bouchair (2004). In addition to the use of climate responsive buildings, people adapt their behavior and activities to the diurnal or seasonal climate changes: the internal migration from one time of day to another, or from one season to another, between parts of the house or areas that provide more comfortable indoor conditions. It should be kept in mind that the body loses radiant heat according to its surface temperature. For a comfortable, normally dressed adult, the weighted average temperature of the bare skin and clothed surfaces is about 27°C. In still air at a temperature near skin temperature, radiant exchange is the principal form of heat exchange between the body and its environment. The MRT affects the rate of radiant heat loss from the body. Since the surrounding surface temperatures may vary widely, the MRT is a weighted average of all radiating surface temperatures within line of sight. It can be calculated as follows: MRT=∑(Tθ)/360, where T is the surface temperature and θ the surface exposure angle (relative to occupant) in degrees.