Progress towards low carbon fuels in the Pacific – prospects and challenges

The use of first generation biofuels in the Pacific has been receiving increasing attention recently. Apart from their contribution to the global emissions reduction effort, they provide the region with one of the most available means of reducing dependence on costly fossil fuel imports. If implemented properly, an indigenous biofuels production programme can contribute to social and economic development, improve energy access as well as providee a valuable means for satisfying the region’s emissions reduction obligations. The challenges with first generation biofuels such as ethanol and vegetable oil-derived fuels are well known. The two main issues commonly aired are the food versus energy debate and the costs of production. The region however offers important advantages not available elsewhere that allows one to reconsider these alternative fuel candidates. These include favourable climate and the apparent availability of marginal land where feedstock such as jatropha and pongamia can thrive. Recent technological advantages in fuel conversion is now stimulating new interest in the potential of these biofuels for the region. However, the successful realization of a biofuels industry for the region must seek answers for some of the barriers to its development that have become increasingly obvious recently. This chapter discusses the present status and future prospects of ethanol and biodiesel as possible transportation and power generation fuels for the region. The range of indigenously available feedstock, including sugar juice, molasses, cassava, for ethanol and coconut oil, pongamia and jatropha for biodiesel are considered, and the possibilities of the commercial realization of hydrotreated vegetable oils (HVO) explored. Barriers to the successful development of a biofuels industry are considered and possible solutions evaluated

Flavin adenine dinucleotide causes oligomerization of acetohydroxyacid synthase from black Mexican sweet corn cells

AbstractAcetohydroxyacid synthase activity is stabilized and stimulated by flavin adenine dinucleotide. Flavin adenine dinucleotide was found to cause aggregation of acetohydroxyacid synthase from the dimeric to a tetrameric form. The different aggregation states of the enzyme have differential sensitivities to inhibition by branched chain amino acids as well as by imazapyr, an imidazolinone herbicide. These observations indicate that flavin adenine dinucleotide is of structural as well as of functional importance for the plant acetohydroxyacid synthase enzyme

Impact of dephasing on non-equilibrium steady-state transport in fermionic chains with long-range hopping

Quantum transport in a non-equilibrium setting plays a fundamental role in understanding the properties of systems ranging from quantum devices to biological systems. Dephasing -- a key aspect of out-of-equilibrium systems -- arises from the interactions with the noisy environment and can profoundly modify transport features. Here, we investigate the impact of dephasing on the non-equilibrium steady-state transport properties of non-interacting fermions on a one-dimensional lattice with long-range hopping ($\sim \frac{1}{r^\alpha}$). We show the emergence of distinct transport regimes as the long-range hopping parameter $\alpha$ is tuned. In the short-range limit ($\alpha \gg 1$), transport is diffusive, while for the long-range limit ($\alpha \sim \mathcal{O}(1)$), we observe a super-diffusive transport regime. Using the numerical simulation of the Lindblad master equation, and corroborated with the analysis of the current operator norm, we identify a critical long-range hopping parameter, $\alpha_c \approx 1.5$, below which super-diffusive transport becomes evident that quickly becomes independent of the dephasing strength. Interstingly, within the super-diffusive regime, we find a crossover from logarithmic to power-law system-size dependence in the non-equilibrium steady-state resistance when $\alpha$ varies from $\alpha \leq 1$ to $\alpha \lesssim 1.5$. Our results, thus, elucidate the intricate balance between dephasing and unitary dynamics, revealing novel steady-state transport features.Comment: Comments are welcom

FIRST AMONG EQUALS: A COMPARATIVE STUDY OF THE EFFECT OF HYDROCHLOROTHIAZIDE AND CHLORTHALIDONE ON RECENTLY DIAGNOSED HYPERTENSIVES

Objective: Thiazide diuretics have been the first choice to treat stable, uncomplicated, essential hypertension; hydrochlorothiazide (HCTZ) beingthe most preferred. Another thiazide, chlorthalidone is available since long and is reported to be equally efficacious if not better in treating primaryhypertension.Aim: To compare the efficacy and safety of HCTZ and chlorthalidone in the management of primary essential hypertension.Methods: We compared these two drugs in a randomized, single-blinded, intention to treat study. Participants with essential hypertension receivedeither chlorthalidone 12.5 mg OD or HCTZ 25 mg OD for a period of 12-week. The results were compared on the basis of 12 hourly ambulatoryblood pressure (BP) monitoring; fortnightly record of serum potassium, and failure of treatment (i.e., the need of additional antihypertensive drugor incrementation in the dose of thiazides).Results: Out of 114,44 in chlorthalidone group and 39 in HCTZ group completed our study. There was a significant mean fall in BP by −11.89/−9.86in the morning time and by −11.12/−7.56 in the evening time in group H receiving HCTZ 25 mg OD. In chlorthalidone group, this mean fall was by−16.45/−12.38 in the morning time and by −15.73/−10.86 in the evening time. After 12 weeks, night time BP control was better in chlorthalidonegroup (127.91±5.01) than HCTZ (132.67±5.19) (p=0.001). Both drugs decreased serum potassium levels, but this decrease was marginally more withHCTZ (3.777±0.601 vs. 3.891±0.534), statistically non-significant when compared to each other (p>0.05).Conclusion: Chlorthalidone is better than HCTZ in controlling BP throughout the day without causing any significant complication.Keywords: Diuretics, Antihypertensive effect, Hydrochlorothiazide, Chlorthalidone, Hypokalemia

Fertilizers and nitrate pollution of surface and ground water: an increasingly pervasive global problem

Nitrate pollution of ground and surface water bodies all over the world is generally linked with continually increasing global fertilizer nitrogen (N) use. But after 1990, with more fertilizer N consumption in developing countries especially in East and South Asia than in the industrialized nations in North America and Europe, nitrate pollution of freshwaters is now increasingly becoming a pervasive global problem. In this review it has been attempted to review the research information generated during the last two decades from all over the world on diferent aspects of nitrate pollution of natural water bodies. It is now evident that not more than 50% of the fertilizer N is directly used by the crops to which it is applied. While a small portion may directly leach down and may reach ground and surface water bodies, a large proportion ends up in the soil organic N pool from where N is mineralized and is taken up by plants and/or lost via leaching during several decades. Present trends of nitrate pollution of freshwaters, therefore, refect legacies of current and past applications of fertilizers and manures. Tools such as simulation models and the natural variation in the stable isotopes of N and oxygen are now being extensively used to study the contribution of fertilizers and other sources to nitrate enrichment of freshwaters. Impacts of agricultural stewardship measures are being assessed and nitrate enrichment of water bodies is being managed using modern digital models and frameworks. Improved water and fertilizer management in agroecosystems can reduce the contribution of fertilizers to nitrate pollution of water bodies but a host of factors determine the magnitude. Future research needs are also considered

Pre-operative Hypoglycemia in Patients Presenting for Surgery: A Hospital Based Cross-sectional Study

Introduction: Peri-operative glycemic control is an important factor for post-operative recovery and is well protocoled for diabetic patients in every setup. It is not always so with non-diabetic patients. This study aimed to observe the pre-operative glucose level and prevalence of hypoglycemia in patients presenting for surgery and its association with the duration of nil per oral period (NPO), age and intravenous fluids used in the pre-operative period. Methods: A cross-sectional study was conducted in the Department of Anesthesiology in a Nepalese medical college including all the patients posted for elective surgery over a period of three months. Socio-demographic and clinical details of the participants were collected in the operating theatre. Duration of  NPO period and intravenous fluid prescribed in the pre-operative fasting period were recorded. A glucose strip test was performed on all the participants. Results: Participants were found to have fasted for an unnecessarily longer duration (12.84±2.27 hours). The incidence of hypoglycemia in patients posted for elective surgery was very high (43.3%). Ringer lactate and normal saline were equally prescribed (38.4%) and dextrose-normal saline was prescribed in the rest of the participants. Gender and type of intravenous fluids were positively correlated whereas NPO period was negatively correlated in overall participants though statistically insignificant. In hypoglycemic participants, we observed that lower glucose was influenced by pre-operative fluids, age and NPO duration. Conclusion: Pre-operative use of glucose-containing fluids during NPO period is an important step to prevent hypoglycemia and related consequences