Pinpointing baobab (Adansonia digitata [Linn. 1759]) population hotspots in the semi-arid areas of Tanzania

The impact of unsustainable land-use conversions, changes in climate and anthropogenic activities on abundance and distribution of baobab populations was assessed in semi-arid regions of Tanzania. Baobabs were sampled in plots of 1 km long and a 50 m wide, which were carried out in 337 grids located in different land-use types. Transects for each land-use type were located using a stratified random sampling technique to compare baobab population variations and occurrences in semi-arid areas of Tanzania. Baobab density was found to be highest in strictly protected areas and the lowest density in unprotected areas, suggesting that anthropogenic activities coupled with local management practices within land-uses may be influencing its viability in semi-arid areas. In species like this, with less and slow recruitment rate, it takes a long time to bring the population to recovery when substantial disturbance and overutilisation have reduced the populations to certain levels. Thus, increased human and climate change pressures on land are likely to drive the species to extinction in these fragmented populations.     

The Fixation of Tissues Vitally Stained with Trypan Blue

The following fixative is recommended for tissues vitally stained with trypan blue: Chloroform, 2 parts; absolute ethyl alcohol, 2 parts; glacial acetic acid, 1 part; mercuric chloride to the point of saturation.

The tissue should be fixed 1 to 2 hours; transferred to 95% ethyl alcohol for 12 hours; to absolute alcohol for 12 to 24 hours; to a mixture of absolute alcohol and xylol for 1/2 hour, and finally to xylol, before embedding in paraffin. Cedar oil may be used for clearing in the place of xylol; in that case the tissues should be transferred from absolute alcohol to a mixture of absolute alcohol and cedar oil for 24 hours before placing in cedar oil alone.

Various counterstains can be used; Mayer's carmalum is excellent.     

Cholesterol metabolism in mice models of genetic hypercholesterolemia

Journal of Physiology and Biochemistry - Monogenic familial hypercholesterolemia is characterized by impaired cellular uptake of apolipoprotein B containing lipoproteins. However, its consequences...