People versus Power: The Geopolitics of Kaptai Dam in Bangladesh

This paper examines the impacts of the Kaptai dam, in the Chittagong Hill Tracts of Bangladesh, on the tribal communities of that area. Kaptai dam is the only hydropower source in Bangladesh, with an installed capacity of 230 MW; about 5% of the electricity consumed in the country is produced there. When the dam was built in 1962, some 100 000 people were displaced and few of them received adequate compensation. Recently, the Power Development Board (PDB) of Bangladesh has announced a plan to install two new 50 MW units that will bring the capacity of the dam to 330 MW. This plan will cause the reservoir water level to rise and may take away about 7500 ha of the fringe land, which the tribal people use for rice cultivation during the April-August period each year. As before, the PDB has not discussed this plan with the potentially affected tribal groups, who are concerned about losing the fringe land and an important source of income. The paper discusses the original displacement issue and this recent development in the light of the geopolitical history of this region. It attempts to present an objective analysis of these issues and views held by various concerned parties. It then proposes a scheme for managing the Kaptai reservoir based on a participatory approach that will ensure both economic efficiency and social equity.     

Direct esterification of fatty acids with phenylalkanols by using dicyclohexylcarbodiimide

A mild one‐pot esterification method of fatty acids with alcohols at room temperature is described. The reaction of undec‐10‐enoic acid (I) with 1‐phenylethanol in the presence of N,N'‐di‐cyclohexylcarbodiimide and 4‐(N,N‐dimethylamino)pyridine gave 1'‐phenylethyl undec‐10‐enoate in quantitative yield. Similar reactions were also carried out with (Z)‐octadec‐9‐enoic acid, (Z)‐12‐hydroxyoctadec‐9‐enoic and (Z)‐9‐hydroxyoctadec‐12‐enoic acids. In addition, compound (I) was allowed to react with diphenyl methanol to form its corresponding ester. The structure elucidation of the prepared esters is based on the elemental analysis and spectral data (IR, ¹H‐ and ¹³C‐NMR, MS).     

Trifostigmanoside I,an Active Compound from Sweet Potato,Restores the Activity of MUC2 and Protects the Tight Junctions through PKCα/β to Maintain Intestinal Barrier Function

Sweet potato (Ipomoea batata) is considered a superfood among vegetables and has been consumed for centuries. Traditionally, sweet potato is used to treat several illnesses, including diarrhea and stomach disorders. This study aimed to explore the protective effect of sweet potato on intestinal barrier function, and to identify the active compounds of sweet potato and their underlying mechanism of action. To this purpose, bioactivity-guided isolation, Western blotting, and immunostaining assays were applied. Interestingly, our bioactivity-guided approach enabled the first isolation and identification of trifostigmanoside I (TS I) from sweet potato. TS I induced mucin production and promoted the phosphorylation of PKCα/β in LS174T human colon cancer cells. In addition, it protected the function of tight junctions in the Caco-2 cell line. These findings suggest that TS I rescued the impaired abilities of MUC2, and protected the tight junctions through PKCα/β, to maintain intestinal barrier function.     

Inhibition of Mild Steel Corrosion Using l-Histidine and Synergistic Surfactants Additives

The corrosion inhibition behavior of nitrogen-containing amino acid l-Histidine (LHS) on mild steel in 0.1 M H₂SO₄ solution in the temperature range of 30-60 °C was studied by weight loss measurements, and potentiodynamic polarization measurements. The effect of the addition of very small concentration of surfactants, sodium dodecyl sulfate (SDS), and cetyltrimethyl ammonium bromide (CTAB), respectively on the corrosion inhibition behavior of LHS was also studied. The surface morphology of the corroded steel samples was evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). LHS significantly reduces the corrosion rates of mild steel, with the maximum inhibition efficiency (IE) being 71.09% at 30 °C in the presence of 500 ppm of LHS. The IE of LHS is synergistically increased in the presence of SDS and CTAB. The SEM and AFM photographs show a clearly different surface morphology in the presence of additives. LHS alone and in combination with surfactants obeys Langmuir adsorption isotherm from the fit of the experimental data of all concentration and temperature studied. The calculated thermodynamic parameters for adsorption reveal strong interaction between the inhibitors and the mild steel surface, and suggest physical adsorption. The results obtained by potentiodynamic polarization measurements are consistent with the results of the weight loss measurement. LHS acts more anodic than cathodic inhibitor.     

Actin Isovariant ACT7 Modulates Root Thermomorphogenesis by Altering Intracellular Auxin Homeostasis

High temperature stress is one of the most threatening abiotic stresses for plants limiting the crop productivity world-wide. Altered developmental responses of plants to moderate-high temperature has been shown to be linked to the intracellular auxin homeostasis regulated by both auxin biosynthesis and transport. Trafficking of the auxin carrier proteins plays a major role in maintaining the cellular auxin homeostasis. The intracellular trafficking largely relies on the cytoskeletal component, actin, which provides track for vesicle movement. Different classes of actin and the isovariants function in regulating various stages of plant development. Although high temperature alters the intracellular trafficking, the role of actin in this process remains obscure. Using isovariant specific vegetative class actin mutants, here we demonstrate that ACTIN 7 (ACT7) isovariant plays an important role in regulating the moderate-high temperature response in Arabidopsis root. Loss of ACT7, but not ACT8 resulted in increased inhibition of root elongation under prolonged moderate-high temperature. Consistently, kinematic analysis revealed a drastic reduction in cell production rate and cell elongation in act7-4 mutant under high temperature. Quantification of actin dynamicity reveals that prolonged moderate-high temperature modulates bundling along with orientation and parallelness of filamentous actin in act7-4 mutant. The hypersensitive response of act7-4 mutant was found to be linked to the altered intracellular auxin distribution, resulted from the reduced abundance of PIN-FORMED PIN1 and PIN2 efflux carriers. Collectively, these results suggest that vegetative class actin isovariant, ACT7 modulates the long-term moderate-high temperature response in Arabidopsis root.     

Development of iron oxide and titania treated fly ash based ceramic and its bioactivity

The increasing accumulation of fly ash from thermal power plants poses a major problem to the environment. The present work reflects the novel utilization of this profusely available industrial waste in the form of an antibacterial hard ceramic material by treating fly ash with ferric oxide (Fe₂O₃) and titania (TiO₂) during sintering process at 1600 °C. The developed material shows more than 90% bacterial reduction against both Gram-positive and Gram-negative bacteria. The mechanism of their antibacterial action was studied by transmission electron microscopy (TEM) image analysis of the bacterial cross-section. The developed ceramic material acquires hardness due to the enhancement of the natural mullite content in the matrix. The mullite content and the crystallinity of mullite have shown their increasing trend with increasing concentration of the metal oxide during sintering process. A maximum of ~ 37% increase in mullite was obtained for 7% w/w Fe₂O₃ and TiO₂. Metal oxide lowered the activation energy of the reaction and enhanced the reaction rate of alumina (Al₂O₃)–silica (SiO₂) to form mullite which increases the hardness. The study highlights novel utilization of fly ash as a hard ceramic antibacterial product (bioceramics) for both structural and hygiene applications in an eco-friendly way.     

Sustainable Development through Groundwater Management: A Case Study on the Barind Tract

Since its birth in 1985, the Barind Multi-purpose Development Project (BMDP) has become a model of a sustainable rural development project in Bangladesh. The project maintains technical soundness by ensuring a high level of water use efficiency and a minimum well spacing. The project runs on full operating and maintenance cost recovery basis, which is achieved through an innovative prepaid water coupon system and the associated command area development scheme. Its governance structure is democratic and participatory. The project has several environmental enhancement programmes such as water conservation, homestead and social forestry, promotion of integrated pest control, and farmers' training. In addition, it has adopted an integrated planning approach that incorporates extending rural electrification, building rural infrastructure and an array of other support programmes. As a result, the BMDP has emerged as a model of sustainable groundwater-based rural development initiative in Bangladesh.