Application of air pollution dispersion modeling for source-contribution assessment and model performance evaluation at integrated industrial estate-Pantnagar

Source-contribution assessment of ambient NO₂ concentration was performed at Pantnagar, India through simulation of two urban mathematical dispersive models namely Gaussian Finite Line Source Model (GFLSM) and Industrial Source Complex Model (ISCST-3) and model performances were evaluated. Principal approaches were development of comprehensive emission inventory, monitoring of traffic density and regional air quality and conclusively simulation of urban dispersive models. Initially, 18 industries were found responsible for emission of 39.11 kg/h of NO₂ through 43 elevated stacks. Further, vehicular emission potential in terms of NO₂ was computed as 7.1 kg/h. Air quality monitoring delineates an annual average NO₂ concentration of 32.6 μg/m³. Finally, GFLSM and ISCST-3 were simulated in conjunction with developed emission inventories and existing meteorological conditions. Models simulation indicated that contribution of NO₂ from industrial and vehicular source was in a range of 45-70% and 9-39%, respectively. Further, statistical analysis revealed satisfactory model performance with an aggregate accuracy of 61.9%.

Pigeonpea genomics initiative (PGI): an international effort to improve crop productivity of pigeonpea (Cajanus cajan L.)

Pigeonpea (Cajanus cajan), an important food legume crop in the semi-arid regions of the world and the second most important pulse crop in India, has an average crop productivity of 780 kg/ha. The relatively low crop yields may be attributed to non-availability of improved cultivars, poor crop husbandry and exposure to a number of biotic and abiotic stresses in pigeonpea growing regions. Narrow genetic diversity in cultivated germplasm has further hampered the effective utilization of conventional breeding as well as development and utilization of genomic tools, resulting in pigeonpea being often referred to as an 'orphan crop legume'. To enable genomics-assisted breeding in this crop, the pigeonpea genomics initiative (PGI) was initiated in late 2006 with funding from Indian Council of Agricultural Research under the umbrella of Indo-US agricultural knowledge initiative, which was further expanded with financial support from the US National Science Foundation's Plant Genome Research Program and the Generation Challenge Program. As a result of the PGI, the last 3 years have witnessed significant progress in development of both genetic as well as genomic resources in this crop through effective collaborations and coordination of genomics activities across several institutes and countries. For instance, 25 mapping populations segregating for a number of biotic and abiotic stresses have been developed or are under development. An 11X-genome coverage bacterial artificial chromosome (BAC) library comprising of 69,120 clones have been developed of which 50,000 clones were end sequenced to generate 87,590 BAC-end sequences (BESs). About 10,000 expressed sequence tags (ESTs) from Sanger sequencing and ca. 2 million short ESTs by 454/FLX sequencing have been generated. A variety of molecular markers have been developed from BESs, microsatellite or simple sequence repeat (SSR)-enriched libraries and mining of ESTs and genomic amplicon sequencing. Of about 21,000 SSRs identified, 6,698 SSRs are under analysis along with 670 orthologous genes using a GoldenGate SNP (single nucleotide polymorphism) genotyping platform, with large scale SNP discovery using Solexa, a next generation sequencing technology, is in progress. Similarly a diversity array technology array comprising of ca. 15,000 features has been developed. In addition, >600 unique nucleotide binding site (NBS) domain containing members of the NBS-leucine rich repeat disease resistance homologs were cloned in pigeonpea; 960 BACs containing these sequences were identified by filter hybridization, BES physical maps developed using high information content fingerprinting. To enrich the genomic resources further, sequenced soybean genome is being analyzed to establish the anchor points between pigeonpea and soybean genomes. In addition, Solexa sequencing is being used to explore the feasibility of generating whole genome sequence. In summary, the collaborative efforts of several research groups under the umbrella of PGI are making significant progress in improving molecular tools in pigeonpea and should significantly benefit pigeonpea genetics and breeding. As these efforts come to fruition, and expanded (depending on funding), pigeonpea would move from an 'orphan legume crop' to one where genomics-assisted breeding approaches for a sustainable crop improvement are routine.

Treatment of rayon grade pulp drain effluent by upflow anaerobic fixed packed bed reactor (UAFPBR)

The Rayon grade pulp (RGP) drain effluent of pulp and paper mill was studied to find out pollutant loading and its control measures by low cost and efficient treatment method. Upflow anaerobic fixed packed bed reactor (UAFPBR) with brick ballasts as packing material was used for this purpose. This was compared with conventional anaerobic treatment method. The digested slurry was taken as inoculum from the active cow dung biogas plant. After stabilization of the reactors the reduction in pollutant loading was found to be higher in UAFPBR than conventional anaerobic reactor (CAR). Hydraulic retention time (HRT) of 12 hr was optimum for the treatment of effluent when 74.5% COD and 81% BOD reduction was obtained. 30% inoculum concentration was best for the anaerobic treatment of RGP colour drain effluent. The maximum biogas production (1.37 l l(-1) of effluent) was when the effluent was inoculated with 30% seeding material. Thus, UAFPBR system was very efficient in terms of BOD, COD, TSS and TDS removal from RGP drain of paper mills in ambient environmental conditions.

Assessment of utilization of RCH services and client satisfaction at different level of health facilities in Varanasi District

OBJECTIVE

To assess the various factors influencing utilization and non-utilization of RCH services and extent of client satisfaction.

METHODS

A cross-sectional study was conducted during October to December 2008 at two selected blocks of Varanasi district, Uttar Pradesh. Principal study subjects were 509 women having children less than 12 months old, selected through a multistage sampling technique. Data were collected through in-depth interview and Focus Group Discussions conducted among the beneficiaries of the services.

RESULTS

The study revealed that utilisation of the RCH services in the government facilities was higher among the backward classes than the general category; higher the level of education the lower was the utilisation of government services. Over all, 16% of the respondents were not satisfied with government facilities. 25% of the SC category was not satisfied with the services in spite of being the main users. Among RCH services utilization was highest (89%) for antenatal care services (ANC). 41.6% respondents did not receive any Post Natal Care (PNC) after their most recent birth. About 30% deliveries were at home out of which only 10% received PNC whereas out of 70% institutional deliveries about 80% received PNC. Overall 16.3 % of the respondents were not satisfied with the services provided by government health facilities. Around 16% and 14% were not satisfied with the behavior of medical officer and the health workers respectively and non-satisfaction was highest among SC category.

CONCLUSION

All health facilities need to be made functional according to Indian Public Health Standards (IPHS) of NRHM.

Influence of diabetes on liver injury induced by antitubercular drugs and on silymarin hepatoprotection in rats

Isoniazid, rifampicin and pyrazinamide during short-course chemotherapy for tuberculosis can result in liver injury. The coexistence of tuberculosis and diabetes is common in patients who receive inadequate treatment. The risk of hepatotoxicity from many toxicants is increased in diabetic rats. Silymarin provides protection against liver injury caused by many hepatotoxicants, including antitubercular drugs (ATDs). In the wake of increased severity of ATD-induced hepatotoxicity in diabetes we report here the results of a study on the influence of diabetes on silymarin hepatoprotection in rats. Rats with diabetes induced via intraperitoneally injected streptozotocin (50 mg/kg), nondiabetic rats and insulin-treated diabetic rats received isoniazid (7.5 mg/kg/day), rifampicin (10 mg/kg/day) and pyrazinamide (35 mg/kg/day) orally (p.o.) with or without silymarin (100 mg/kg/day p.o.) treatment for 45 days. Compared to nondiabetic rats, liver function tests and histological changes of liver revealed exaggerated liver injury in diabetic rats caused by ATDs which was evident by 5- to 8-fold increases in serum levels of marker enzymes (aspartate and alanine aminotransferase, alkaline phosphatase and gamma-glutamyltranspeptidase) and 1- to 2-fold increases in bilirubin accompanied by a 2-fold decrease in total serum proteins, intense fatty and inflammatory infiltrations, necrosis and fibrosis. Coadministration of silymarin provided protection against ATD hepatotoxicity in all animals. However, insulin-treated diabetic animals showed greater silymarin-induced hepatoprotection against ATD-induced liver injury, which was characterized by near normal levels of marker enzymes, an increase in total proteins and normal hepatic structure. These results thus indicate that diabetes exaggerates ATD-induced liver injury and attenuates silymarin-induced hepatoprotection. However, insulin treatment for diabetes offers greater silymarin-induced hepatoprotection against ATD-induced liver injury.

In vitro effect of fluoroquinolones against Mycobacterium tuberculosis isolates from Agra & Kanpur region of north India

BACKGROUND & OBJECTIVE

Fluoroquinolones (FQs) are important drugs used for treatment of drug resistant tuberculosis and are also now being considered as first line drugs to shorten the duration of treatment of tuberculosis (TB). In order to find out useful FQs for treatment of tuberculosis, the comparative efficacy of five FQs, namely, ofloxacin (OFL), ciprofloxacin (CIP), sparfloxacin (SPX), gatifloxacin (GAT) and levofloxacin (LEVX) was studied against Mycobacterium tuberculosis (MTB) isolates obtained from both treated and untreated patients from Agra and Kanpur regions of north India.

METHODS

A total of 162 MTB isolates [including 110 MTB isolates obtained from untreated patients (Cat-I) and 52 isolates from treated patients (Cat-II)] were tested for their susceptibilities to FQs using standard minimum inhibitory concentration (MIC) method on Löwenstein-Jensen medium.

RESULTS

Keeping in view the therapeutically achievable drug levels, it was found that in Cat-I 97.2 per cent (107/110) isolates were sensitive to GAT, 89 per cent (98/110) to LEVX at 1 microg/ml whereas 92.7 per cent (102/110) isolates were inhibited by OFL at 2 microg/ml and 73.6 per cent (81/110) to SPX at 0.5 microg/ml. Only 63.6 per cent (70/110) isolates were found to be sensitive to CIP at 2 microg/ml which increased to 89 per cent (98/110) at 4 microg/ml (higher than achievable peak serum level). On the other hand, among 52 isolates for Cat-II, 37 (71.2%) were found to be sensitive to GAT and 33 (63.5%) to LEVX at 1 microg/ml concentration, 28 (53.8%) to SPX at 0.5 microg/ml whereas 33 (63.5%) and 24 (46.2%) isolates were found to be sensitive to OFL and CIP at 2 microg/ml, respectively.

INTERPRETATION & CONCLUSION

It appears that GAT has higher activity against MTB isolates followed by OFL, LEVX and SPX whereas CIP showed the lowest activity. GAT was also found to be the most effective FQ against multi-drug resistant (MDR) isolates both from Cat-I and Cat-II patients. Thus, except CIP, other FQs showed potential to be included in the treatment regimens of tuberculosis including MDR-TB.

Chronic kidney disease in India: challenges and solutions

Chronic diseases have become a major cause of global morbidity and mortality even in developing countries. The burden of chronic kidney disease (CKD) in India cannot be assessed accurately. The approximate prevalence of CKD is 800 per million population (pmp), and the incidence of end-stage renal disease (ESRD) is 150-200 pmp. The most common cause of CKD in population-based studies is diabetic nephropathy. India currently has 820+ nephrologists, 710+ hemodialysis units with 2,500+ dialysis stations and 4,800+ patients on CAPD. There are 172+ transplant centers, two-thirds of which are in South India and mostly privately run. Nearly 3,500 transplants are done annually, the total number of cadaver donors being approximately 700 till now. Thus, taken together, nearly 18,000-20,000 patients (10% of new ESRD cases) in India get renal replacement therapy. The cost of single hemodialysis varies between USD 15 and 40 with an additional cost of erythropoietin being USD 150-200/month. The cost of CAPD using a 'Y' set with 3 exchanges/week is USD 400/month. The cost of the transplant procedure in a state-run hospital is USD 800-1,000, and the cost of immunosuppression using tacrolimus, steroid and mycophenolate is USD 350-400/month. Until recently, the government did not recognize CKD/ESRD as a significant problem in India. However, some illustrious activities in relation to CKD brought attention of the media and policymakers to this very common but till now deprived group of diseases. On the one side the government has initiated a process by which it is planning to establish stand-alone hemodialysis units in the country to increase the facilities at an affordable cost, and on the transplant side it had launched a National Organ Transplant Program to facilitate transplantation on a national scale. Hemodialysis program is halfway to being implemented. Thus, in India there is still a long way to go with respect to CKD. Until then, in a country like India, screening of high-risk individuals for CKD and the risk factors is the best bet.

Extraction of acidic degradation products of organophosphorus chemical warfare agents

The analysis of alkyl alkylphosphonic acids (AAPAs) and alkylphosphonic acids (APAs), the hydrolyzed products of nerve agents, constitutes an important aspect for verifying the compliance to the Chemical weapons convention (CWC). This work devotes on the development of solid-phase extraction method using polymeric mixed-mode strong anion-exchange (Oasis MAX) cartridges for extraction of AAPAs and APAs from water. The extracted analytes were analyzed by GC-MS under full scan and selected ion monitoring mode. The extraction efficiencies of MAX and silica-based anion-exchange cartridges were compared, and results revealed that MAX sorbents yielded better recoveries. Extraction parameters, such as loading capacity, extraction solvent, its volume, and washing solvent were optimized. Best recoveries were obtained using 1 mL of acidic methanol (0.1 M), and limits of detection could be achieved up to 5 x 10(-4) microg mL(-1) (in SIM) and 0.05 microg mL(-1) in full scan mode. The method was successfully employed for the detection and identification of alkylphosphonic acids present in soil sample sent by the Organization for Prohibition of Chemical Weapons (OPCW) in the official proficiency tests.

Application of Doehlert design in optimizing the determination of degraded products of nerve agents by ion-pair liquid chromatography electrospray ionization tandem mass spectrometry

A qualitative method was developed for the determination of degraded products of nerve agents by using ion-pair liquid chromatography electrospray ionization tandem mass spectrometry (IP-LC-ESI-MS(n)). Generally, alkylphosphonic acids (APAs) and O-alkyl alkylphosphonic acids (AAPAs) give deprotonated molecular ion [M-H](-) in negative mode. Interestingly, first time we obtained the molecular radical anion [M](.-) of phosphonic acids in negative mode by using tri-n-butyl amine as an ion-pairing agent. We interpreted this observation as an indication of electrochemical reduction of phosphonic acids in electrospray needle. Three variables such as sheath gas flow, electrospray needle voltage and pH of the mobile phase were investigated to enhance the molecular radical anion [M](.-) signal of each analyte. The Doehlert design was used to obtain the region in which the optimum value of such variables is simultaneously achieved. Limit of detection achieved was 0.5 microg mL(-1) for AAPAs and 10 microg mL(-1) for APAs. Excellent precision was observed with less than 8.61% RSD. Finally, the method was applied for the detection of ethyl methylphosphonic in aqueous extract of soil sample.

Characterization of mycobacteria isolated from bovines by PRA-targetting hsp 65 gene region

Bovine tuberculosis caused by the bacterium Mycobacterium bovis is a major infectious disease of animals and has zoonotic importance for humans. Even though the incidence is believed to be very low in India, human tuberculosis caused by M. bovis has been increasingly recognized in many other countries of the world. As differentiation of mycobacterial species take long time, a method for the rapid identification of mycobacteria isolated from bovine samples to the species level was used, which is based on polymerase chain reaction (PCR) of the gene encoding for the 65-kD protein followed by restriction analysis. The method involves restriction enzyme analysis of PCR products obtained with primers common to all mycobacteria and generate M. tuberculosis complex specific pattern. PRA was performed on 33 bovine isolates of which 90.9% (30/33) isolates were identified clearly as M. tuberculosis complex, M. fortuitum, M. phlei and M. smegmatis using restriction enzyme Hae III.

Electrospray ionization tandem mass spectral analysis of oxidation products of precursors of sulfur mustards

Electrospray ionization tandem mass spectral (ESI-MSn) analysis of thiodiglycol, bis(2-hydroxyethylthio)alkanes (BHETAs) and their mono-, di-, tri-, and tetraoxygenated compounds was carried out to obtain their characteristic spectra for ESI-MS analysis. These compounds are important markers of chemical warfare agents, namely sulfur mustards. ESI-MSn (n > or = 3) analysis of a compound by collisionally induced dissociation in an ion trap gives rise to mass spectra that are somewhat similar to electron ionization mass spectra. These ESI-MSn spectra can be used for compound identification. Under ESI-MS and ESI-MS/MS the compounds mostly produced [M+NH4]+, [M+H]+ and [M+H--H2O]+ ions. Fragmentations of these even-electron precursors in the ion trap gave rise to characteristic product ions via neutral loss of O2, H2O, C2H4, HCHO, C2H4O, C2H4S, HSC2H4OH and C2H4SO. Fragmentation routes of these compounds are proposed that rationalize the formation of product ions in ESI-MSn analysis.

Effect of estrogen on hypoglycemia induced neurological impairment in ovariectomized rats

The risk of hypoglycemia and the resulting functional derangement of the brain are one of the major complications with stringently controlled diabetes mellitus. Ovarian steroid hormones, particularly estradiol, play a modulatory role in the ability of the female brain to utilize glucose. In the present study, the effects of estrogen on hypoglycemia-induced neurological impairment were done in ovariectomized rats. Animals received either vehicle or estradiol benzoate treatment. Hypoglycemia (Blood glucose levels <50 mg/dl) was induced in all the rats by insulin (2 U/kg, IP). Neurological functions were assessed using an 18 point scale at different time intervals of hypoglycemia. Estradiol benzoate (100 microg/kg IP) significantly (p<0.05) deteriorated the neurological functions in ovariectomized rats during hypoglycemia. The present study thus reveals that estradiol benzoate is responsible for further aggravation of neurological impairment induced by insulin hypoglycemia in female rats.

Research priorities for rice pest management in tropical Asia: a simulation analysis of yield losses and management efficiencies

ABSTRACT A simulation study was conducted to assess the current and prospective efficiency of rice pest management and develop research priorities for lowland production situations in tropical Asia. Simulation modeling with the RICEPEST model provided the flexibility required to address varying production situations and diverse pest profiles (bacterial leaf blight, sheath blight, brown spot, leaf blast, neck blast, sheath rot, white heads, dead hearts, brown plant-hoppers, insect defoliators, and weeds). Operational definitions for management efficacy (injury reduction) and management efficiency (yield gain) were developed. This approach enabled the modeling of scenarios pertaining to different pest management strategies within the agroecological contexts of rice production and their associated pest injuries. Rice pests could be classified into two broad research priority-setting categories with respect to simulated yield losses and management efficiencies. One group, including weeds, sheath blight, and brown spot, consists of pests for which effective pest management tools need to be developed. The second group consists of leaf blast, neck blast, bacterial leaf blight, and brown plant-hoppers, for which the efficiency of current management methods is to be maintained. Simulated yield losses in future production situations indicated that a new type of rice plant with high-harvest index and high-biomass production ("New Plant Type") was more vulnerable to pests than hybrid rice. Simulations also indicated that the impact of deployment of host resistance (e.g., through genetic engineering) was much larger when targeted against sheath blight than when targeted against stem borers. Simulated yield losses for combinations of production situations and injury profiles that dominate current lowland rice production in tropical Asia ranged from 140 to 230 g m(-2). For these combinations, the simulated efficiency of current pest management methods, expressed in terms of relative yield gains, ranged from 0.38 to 0.74. Overall, the analyses indicated that 120 to 200 x 10(6) tons of grain yield are lost yearly to pests over the 87 x 10(6) ha of lowland rice in tropical Asia. This also amounts to the potential gain that future pest management strategies could achieve, if deployed.

Emissions of sulfur trioxide from coal-fired power plants

Emissions of sulfur trioxide (SO3) are a key component of plume opacity and acid deposition. Consequently, these emissions need to be low enough to not cause opacity violations and acid deposition. Generally, a small fraction of sulfur (S) in coal is converted to SO3 in coal-fired combustion devices such as electric utility boilers. The emissions of SO3 from such a boiler depend on coal S content, combustion conditions, flue gas characteristics, and air pollution devices being used. It is well known that the catalyst used in the selective catalytic reduction (SCR) technology for nitrogen oxides control oxidizes a small fraction of sulfur dioxide in the flue gas to SO3. The extent of this oxidation depends on the catalyst formulation and SCR operating conditions. Gas-phase SO3 and sulfuric acid, on being quenched in plant equipment (e.g., air preheater and wet scrubber), result in fine acidic mist, which can cause increased plume opacity and undesirable emissions. Recently, such effects have been observed at plants firing high-S coal and equipped with SCR systems and wet scrubbers. This paper investigates the factors that affect acidic mist production in coal-fired electric utility boilers and discusses approaches for mitigating emission of this mist.

The annual risk of tuberculous infection in the eastern zone of India

SETTING

Rural and urban areas of eight selected districts in the eastern zone of India.

OBJECTIVES

To estimate the annual risk of tuberculous infection (ARTI).

STUDY DESIGN

A community-based, cross-sectional tuberculin survey was conducted among children aged 1-9 years residing in a sample of rural and urban areas. Stratified two-stage cluster sampling was adopted for selection of rural and urban clusters. A total of 40964 children in 515 clusters underwent tuberculin testing and reading with 1TU PPD RT23 with Tween 80; the maximum transverse diameter of induration was measured about 72 h after the test.

RESULTS

A bacille Calmette-Gúerin (BCG) scar was observed in 51.5% of the test-read children. The frequency distribution of tuberculin reaction size among 19332 children without BCG scar was found to be bimodal, with the mode of reactions attributable to infection with tubercle bacilli at 20 mm. The prevalence of infection was estimated as 6.9%. The ARTI computed from the estimated prevalence was 1.3%. Children residing in the urban areas were found to be at a significantly higher risk of infection than those residing in rural areas.

CONCLUSION

The high rate of ARTI in the eastern zone of India suggests a need for committed, sustained action in provision of quality tuberculosis control services.

Effect of insulin hypoglycemic stress on nociceptive responses to mu- and kappa-opioid receptor agonists at LH-surge in female rats

In a randomized, prospective, controlled and crossover study, the effects of insulin hypoglycemic stress on nociceptive responses to mu- and kappa-opioid receptor directed drugs during steroid-induced preovulatory LH-surge were seen in ovariectomized female rats. Ovariectomized rats were equally distributed in two groups of 10. In group 1 rats, LH-surge was induced by sequential treatment with estradiol benzoate 7.5 micro g/rat s.c. and progesterone 5 mg/rat s.c., whereas in group 2 rats, vehicles of estradiol benzoate and progesterone were given in a sequential manner. A third group consisted of sham-operated rats, which received no treatment. Rats were exposed to insulin-induced hypoglycemic stress 1 h before the peak of LH-surge. Antinociceptive responses of morphine, buprenorphine and pentazocine were observed at peak LH-surge during hypoglycemic stress. Increased nociceptive responses to noxious stimulus and decreased percent maximal possible effect for morphine, buprenorphine and pentazocine at LH-surge were significantly (p < 0.01) reversed during insulin hypoglycemic stress. There was a significant (p < 0.01) decrease in the ED(50) values of morphine, buprenorphine and pentazocine during hypoglycemic stress. The present study indicates that insulin hypoglycemic stress is responsible for increased antinociceptive activities of morphine, buprenorphine and pentazocine and decreased sensitivity to noxious stimulus in ovariectomized rats with or without steroid-induced LH-surge.

Flue gas desulfurization: the state of the art

Coal-fired electricity-generating plants may use SO2 scrubbers to meet the requirements of Phase II of the Acid Rain SO2 Reduction Program. Additionally, the use of scrubbers can result in reduction of Hg and other emissions from combustion sources. It is timely, therefore, to examine the current status of SO2 scrubbing technologies. This paper presents a comprehensive review of the state of the art in flue gas desulfurization (FGD) technologies for coal-fired boilers. Data on worldwide FGD applications reveal that wet FGD technologies, and specifically wet limestone FGD, have been predominantly selected over other FGD technologies. However, lime spray drying (LSD) is being used at the majority of the plants employing dry FGD technologies. Additional review of the U.S. FGD technology applications that began operation in 1991 through 1995 reveals that FGD processes of choice recently in the United States have been wet limestone FGD, magnesium-enhanced lime (MEL), and LSD. Further, of the wet limestone processes, limestone forced oxidation (LSFO) has been used most often in recent applications. The SO2 removal performance of scrubbers has been reviewed. Data reflect that most wet limestone and LSD installations appear to be capable of approximately 90% SO2 removal. Advanced, state-of-the-art wet scrubbers can provide SO2 removal in excess of 95%. Costs associated with state-of-the-art applications of LSFO, MEL, and LSD technologies have been analyzed with appropriate cost models. Analyses indicate that the capital cost of an LSD system is lower than those of same capacity LSFO and MEL systems, reflective of the relatively less complex hardware used in LSD. Analyses also reflect that, based on total annualized cost and SO2 removal requirements: (1) plants up to approximately 250 MWe in size and firing low- to medium-sulfur coals (i.e., coals with a sulfur content of 2% or lower) may use LSD; and (2) plants larger than 250 MWe and firing medium- to high-sulfur coals (i.e., coals with a sulfur content of 2% or higher) may use either LSFO or MEL.