Heat shock proteins (HSP) are essential for intracellular protein folding during stress and protect cells from denaturation and aggregation cascades that can lead to cell death. HSP genes are regulated at the transcriptional level by heat shock transcription factor 1 (HSF1) that is activated by stress and binds to heat shock elements in HSP genes. The activation of HSF1 during heat shock involves conversion from an inert monomer to a DNA binding trimer through a series of intramolecular folding rearrangements. However, the trigger for HSF1 at the molecular level is unclear and hypotheses for this process include reversal of feedback inhibition of HSF1 by molecular chaperones and heat-induced binding to large non-coding RNAs. Heat shock also causes a profound modulation in cell signaling pathways that lead to protein kinase activation and phosphorylation of HSF1 at a number of regulatory serine residues. HSP genes themselves exist in an accessible chromatin conformation already bound to RNA polymerase II. The RNA polymerase II is paused on HSP promoters after transcribing a short RNA sequence proximal to the promoter. Activation by heat shock involves HSF1 binding to the promoter and release of the paused RNA polymerase II followed by further rounds of transcriptional initiation and elongation. HSF1 is thus involved in both initiation and elongation of HSP RNA transcripts. Recent studies indicate important roles for histone modifications on HSP genes during heat shock. Histone modification occurs rapidly after stress and may be involved in promoting nucleosome remodeling on HSP promoters and in the open reading frames of HSP genes. Understanding these processes may be key to evaluating mechanisms of deregulated HSP expression that plays a key role in neurodegeneration and cancer.

An economic anylysis was made to determine the cost of fish production in the floodplains at Daudkandi Upazilla in Comilla district during the period form January to April, 2007. Survey method was followed to collect data from 20 floodplain aquaculture projects. The projects record books and personal interviews of the NGOs and Fisheries officers were the main instruments of data collection. Statistical tools such as: range, mean, standard deviation and percentage were employed for analysis of data. The Cobb-Douglas production function model was used to estimate the values of co-efficients and related statistics of production function of fish culture in floodplains. Out of eleven explanatory variables, seven co-efficients had positive sign while only four co-efficients showed negative sign. The co-efficients bearing positive sign i.e., embankment construction, nursery and land lease, fertilizer and lime, fingerlings, feed, labor and staff wages and miscellaneous cost made positive impact on the farm income, while the co-efficients having negative sign i.e., area of floodplain, Office management, compensation and harvesting and marketing cost decreased the farm income. Summation of the production co-efficients i.e., return to scale (∑bi) was found 1.023 which implies that per one taka investment in floodplain fish culture will give rise to a profit of Tk. 1.02. The value of R 2 was found 0.892, which means that the variations in farm income could be explained to the extent of 89.2% by the included variables. The remaining 10.8% variations could not be accounted for by the multiple regression analysis. Average fish production in the selected floodplains was 2920.43 kg/ha of which production of cultured fish and indigenous fish was 2697.35 and 223.08 kg/ha respectively. The cost of fish production, total return and net income were estimated Tk. 1,153,08.55, 1,76,385.49 and 61,076.94 /ha. respectively. Benefit cost ratio was found 1.53.

With a view to get a pen picture about the trend and extent of quality changes and as well as shelf life of the head off and head on shrimp (Macrobrachium rosenbergii, De Man, 1879), the present study have been carried out . Quality changes have been measured by application of sensory score evaluation and changes in chemical indices such as Total Volatile Nitrogen (TVN) value, pH and level of moisture at different time interval and Total Bacterial Count (TBC) at 15 o C during the study period. The results of the sensory score evaluation indicates that the shrimp quality decreased to the limits of acceptability at 12th days of ice storage. The head off shrimp kept slight better than corresponding head on shrimps. The bacterial counts determined at 15 o C have been found to increase from 10 3 -10 7 and 10 4 -10 8 cfu/gm for head off and head on shrimp respectively at the limit of acceptability. The moisture level increased from initial 78.85gm% to final 83.80gm% (head off) & 79.0gm% to 84.0gm% (head on) and pH value increases from 7.1 to 8.1 during the whole period of iced preservation . Both head off and head on shrimp remained in acceptable condition for up to 12 and 14 days of storage respectively while the quality of fish deteriorates and become unacceptable. The bacterial count corresponding to unacceptable condition ranges from 10 8 -10 9 cfu/gm fish sample. The TVN value corresponding to rejection condition were 45-50mg N/100gm fish sample.

Wheat (Triticum aestivum L.) was planted as winter crop using raised bed and conventional planting system with four N levels at Regional Wheat Research Station, Rajshahi (latitude 28°75′ N and longitude 92°58′ E), during November to March in 2002 and 2003 to study N content in grain and straw, uptake of total nitrogen, N use efficiency, fertilizer recovery percentage and grain yield. The highest N content in grain and straw were obtained from bed planting system with Shatabdi at 150% N treatment. Maximum total N uptake by the plants was found in bed elevation as compared to conventional planting system. The highest N use efficiency was observed at N zero treatment as compared to applied N levels. Shatabdi noticed highest N use efficiency among the crop varieties. The maximum fertilizer recovery percentage was noted in Shatabdi under bed planting system. The highest grain yield (2,555 kg/ha) was produced from bed planting system. Significantly the highest grain yield (2,929 kg/ha) was found in Shatabdi. The highest grain yield (3,746 kg/ha) was found when 150% N was applied. In bed planting system, the highest grain yield (3,323 kg/ha) was produced when 150% N was applied. The lowest grain yield (1,177 kg/ha) was obtained in zero N treatment. Among the varieties, Shatabdi was the best performer in bed planting system due to maximum nitrogen and protein content in grain and straw, maximum N use efficiency and fertilizer recovery percentage.