Deeper Still

Subhash Mukhopadhyay 한인문화연구원 1991 한인문화논총 Vol.9ㆍ10 No.-

Body melanization and its adaptive role in thermoregulation and tolerance against desiccating conditions in drosophilids

Subhash RAJPUROHIT,Ravi PARKASH,Seema RAMNIWAS 한국곤충학회 2008 Entomological Research Vol.38 No.1

Melanism seems to have evolved independently through diverse mechanisms in various taxa and different ecological factors could be responsible for selective responses. Increased body melanization at higher altitudes as well as latitudes is generally considered to be adaptive for thermoregulation. Physiological traits such as body melanization and desiccation resistance have been investigated independently in diverse insect taxa at three levels: within populations, between populations and among species. A substantial number of Drosophila studies have reported clinal variations in both these traits along latitude. A possible link between these traits had remained unexplored in wild and laboratory populations of ectothermic insect taxa, including drosophilids, to date. Simultaneous analysis of these traits in assorted darker and lighter phenotypes in each population in the present study showed parallel changes for body melanization and desiccation resistance. The mechanistic basis of evolving desiccation resistance was explained on the basis of differential rates of water loss per hour in darker versus lighter phenotypes in six populations of Drosophila melanogaster from adjacent localities differing substantially in altitude all along the Indian subcontinent. Data on cuticular impermeability suggest a possible role of melanization in desiccation tolerance. However, substantial gaps remain in extending these results to other insect taxa and further exploring the physiological and molecular changes involved in melanization for conferring desiccation resistance.

Skermanella mucosa sp. nov., isolated from crude oil contaminated soil

Subhash, Y.,Yoon, D. E.,Lee, S. S. Kluwer Academic Publishers [etc.] 2017 Antonie van Leeuwenhoek Vol.110 No.8

<P>A novel Gram-stain negative, small rod-shaped bacterium (strain 8-14-6(T)) was isolated from hydrocarbon contaminated desert soil collected from Kuwait. Strain 8-14-6(T) grew at 5-37 A degrees C, pH 6.0-8.8 and 0-2% (w/v) of NaCl concentration. Casein, starch, Tween 20 and Tween 80 were hydrolyzed while urea, chitin, DNA and carboxymethyl-cellulose were not hydrolyzed by strain 8-14-6(T). The major cellular fatty acids were identified as C-18:1 omega 6c/C-18:1 omega 7c, C-16:0 and iso-C16:1I/C(14:0)3-OH. Strain 8-14-6(T) produced diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified phospholipids, two unidentified lipids and five unidentified amino lipids as polar lipids. Genomic G+C content was 73.5 mol %. 16S rRNA gene sequence comparisons indicated that strain 8-14-6(T) represents a member of the genus Skermanella within family Rhodospirillaceae of the class Alphaproteobacteria. Strain 8-14-6(T) has a sequence similarity of 98.9% with Skermanella rosea M1(T), 97.4% with Skermanella aerolata 5416T-32(T), 96.9% with Skermanella stibiiresistens SB22(T) and < 95.4% with the other two known species of the genus Skermanella. The DNA-DNA relatedness values between strain 8-14-6(T) and the type strains of the closely related species were clearly below the 70% threshold. From the combination of phenotypic and genotypic characteristics and distinct phylogenetic position, the strain is considered to represent a novel species of the genus Skermanella, for which the name Skermanella mucosa sp. nov. is proposed. The type strain is 8-14-6(T) (=KEMB 2255-438(T) =JCM 31590(T)).</P>

Rhodobacter sediminis sp. nov., isolated from lagoon sediments

Subhash, Y.,Lee, Sang-Seob Microbiology Society 2016 International journal of systematic and evolutiona Vol.66 No.-

Dynamic System Modeling for Closed Loop Supply Chains System

Subhash Wadhwa,Jitendra Madaan 대한산업공학회 2008 Industrial Engineeering & Management Systems Vol.7 No.1

The need for holistic modeling efforts for returns that capture the extended closed loop supply chain (CLSC) system at strategic as well as operational level has been clearly recognized by the industry and academia. Strategic decision-makers need comprehensive models that can guide them in efficient decision-making to increase the profitability of the entire forward and return chain. Therefore, determination of a near optimal design configuration, which includes the environmental, economical and technological capability factors, is important in strategic decision-making effort that affect the profitability of the closed loop supply chain. In this paper, we adopted an improved system dynamics methodology to tackle strategic issues that affect various performance measures, like market, time/cost, environment etc., for closed loop supply chains. After studying real life implementation issues in CLSC design, we presented guidelines for the PBM (Participative Business Modeling) methodology and presented its extension for the strategic dynamic system modeling of return chains. Finally, we demonstrated the measurement of operational performance by extending SD (system dynamic) application to closed loop supply chain management.

Aneurinibacillus sediminis sp. nov., isolated from lagoon sediments

Subhash, Y.,Kim, Hye-ji,Lee, Sang-Seob Society for General Microbiology 2017 International journal of systematic and evolutiona Vol.67 No.8

<P> Two bacterial strains (1-10M-8-7-50<SUP>T</SUP> and 1M) were isolated from lagoon sediments. The strains were obligately aerobic, Gram-stain-positive, spore-forming, rod-shaped and motile. Both strains were able to grow at 25-60 °C (optimum 40-42 °C), at pH 6.0-8.8 (optimum pH 7.0-7.5) and with 0-2.0% (w/v) (optimum 0-0.8 %) NaCl. The predominant cellular fatty acids were iso-C<SUB>15 : 0</SUB> and iso-C<SUB>15 : 0</SUB> 2-OH, and the cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid, glycine and alanine. Phosphatidyl-N-methylethanolamine, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, two unidentified phosphoglycolipids and three unidentified lipids were present as polar lipids. Genomic DNA G+C content was 41.9 mol%. 16S rRNA gene sequence comparisons of both strains indicated that they belong to the genus Aneurinibacillus within the family Paenibacillaceae of the class Bacilli. Both strains had a sequence similarity of 97.6% with Aneurinibacillus migulanus B0270<SUP>T</SUP>, 97.6% with Aneurinibacillus aneurinilyticus ATCC 12856<SUP>T</SUP>, 97.5% with 'Aneurinibacillus humi' U33 and <97% with other members of the genus Aneurinibacillus. The DNA-DNA reassociation value between strain 1-10M-8-7-50<SUP>T</SUP> and 1M was >90 %, while strains 1-10M-8-7-50<SUP>T</SUP> and 1M were only 35.1±1, 29.8±1 and 24.5±1%related to A. migulanus KACC 18173<SUP>T</SUP>, A. aneurinilyticus KACC 18174<SUP>T</SUP> and 'A. humi' U33, respectively. Distinct morphological, physiological and genotypic differences from the previously described taxa support the classification of strain 1-10M-8-7-50<SUP>T</SUP> as a representative of a novel species in the genus Aneurinibacillus, for which the name Aneurinibacillus sediminis sp. nov. is proposed. The type strain is 1-10M-8-7-50<SUP>T</SUP>(=KEMB 563-460<SUP>T</SUP>=JCM 31819<SUP>T</SUP>). </P>

Climate change, boundary increase and elongation of a pre-existing cline: A case study in Drosophila ananassae

Subhash RAJPUROHIT,Ravi PARKASH,Shama SINGH,Seema RAMNIWAS 한국곤충학회 2008 Entomological Research Vol.38 No.4

During the past two to three decades, Drosophila ananassae, a warm adapted tropical species, has invaded low to mid altitude localities in the western Himalayas. Due to its cold sensitivity, this species had never been recorded from higher latitudes as well as altitudes in India to the 1960s. A latitudinal cline in this desiccation-sensitive species corresponds with southern humid tropical localities rather than northern drier subtropical localities. An extension of its cline into lowland to midland montane localities has resulted due to global climatic change as well as local thermal effects through anthropogenic impact. However, D. ananassae populations at species borders are characterized by lower genetic variability for body melanization as well as for desiccation resistance. There is a lack of thermal plastic effects for body melanization, and the observed extended cline might represent evolutionary (genetic) response due to selection pressure imposed by drier habitats. A comparison of fecundity, hatchability and viability at three growth temperatures (17, 20 and 25°C) showed significant reduction in trait values at 17 °C in D. ananassae. Thus, its recent range expansion into northern montane localities might involve genetic effects on stress-related traits and plastic effects on life history traits. We suggest that D. ananassae could serve as an indicator species for analyzing range expansion under changing climatic conditions.

Parametric study on the performance of solar air heater equipped with louvered fins

Subhash Chand,Prabha Chand 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

A theoretical model is developed in this study to investigate the performance of solar air collector equipped with louvered fins. Parameters, such as mass flow rate, fin spacing, louvered pitch ratio (w/Lp), and louvered angle, are considered. The governing equations are solved using a computer code that employs an iterative solution procedure, and the obtained results are compared with that using plain solar air heater. The thermal efficiency of the plain solar air heater is enhanced from 43.14 % to 76.79 % by employing louvered fins with fin spacing values of 5 and 1 cm at a constant mass flow rate of 0.020 kg/s. However, the pressure drop effect becomes dominant that decreases the effective efficiency by 9.4 % at a high mass flow rate of 0.083 kg/s.

Description of Comamonas sediminis sp. nov., isolated from lagoon sediments

Subhash, Y.,Bang, John J.,You, Taek H.,Lee, Sang-Seob Society for General Microbiology 2016 International journal of systematic and evolutiona Vol.66 No.-

<P>Strain S3(T) was isolated from lagoon sediments, and appeared as transparent colonies on agar plates, with cells staining Gram-negative. Catalase and oxidase were positive. S3(T) hydrolyzed starch, casein and tween-20, while urea, chitin, gelatin and tween-80 were not hydrolysed. C-18:1 omega 6C/C-18:1 omega 7C, C-16:1 omega 6C/C-16:1 omega 7c,C-17:0 cyclo and C-16:0 were the predominant fatty acids with minor amounts of C-10:0 3-OH, C-12:0, C-14:0 and C-16:0 2-OH. S3(T) contained diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), and phosphatidylethanolamine (PE) as major polar lipids with minor amounts of unidentified phospholipid (PL) and unidentified lipids (L1-2). Genomic DNA G+C content was 68.3 mol%. 16S rRNA gene sequence comparisons indicated that S3(T) represents a member of the genus Comamonas in family Comamonadaceae of the class Betaproteobacteria. S3(T) has a sequence similarity of 98.96% with Comamonas koreensis YH12(T), 97.93% with Comamonas guangdongensis CY01(T) and <96.97% with other members of the genus Comamonas. DNA DNA hybridization values between S3(T) and the type strains of the most closely related species were clearly below the 70% threshold. On the basis of phenotypic, genotypic and phylogenetic analysis, it is proposed that S3(T) represents a novel species of the genus Comamonas, for which the name Comamonas sediminis sp. nov. is proposed. The type strain is S3(T) (=KEMB 563-466(T) =JCM 31169(T)).</P>

Description of Oceanispirochaeta sediminicola gen. nov., sp. nov., an obligately anaerobic bacterium isolated from coastal marine sediments, and reclassification of Spirochaeta litoralis as Oceanispirochaeta litoralis comb. nov.

Subhash, Y.,Lee, Sang-Seob Society for General Microbiology 2017 International journal of systematic and evolutiona Vol.67 No.9

<P> An obligately anaerobic spirochaete (strain SY2<SUP>T</SUP>) was isolated from coastal marine sediments of Tongyeong-Si, South Korea. Strain SY2<SUP>T</SUP> was helical-shaped and Gram-stain-negative. Strain SY2<SUP>T</SUP> was able to grow at 10-40 °C (optima, 25-30 °C), pH 6.3-8.8 (optima, pH 7.0-8.0) and with 1-7% (optimum, 2-3 %) NaCl concentration. Strain SY2<SUP>T</SUP> was negative for catalase and oxidase activity. The major end-products of glucose fermentation were acetate, ethanol, hydrogen and carbon dioxide. C<SUB>14 : 0</SUB>, C<SUB>16 : 0</SUB>, iso-C<SUB>15 : 0</SUB>, iso-C<SUB>14 : 0</SUB> 3-OH, iso-C<SUB>15 : 1</SUB> H/C<SUB>13 : 0</SUB> 3-OH and iso-C<SUB>17 : 1</SUB>ω9c were predominant fatty acids (>5 %) with minor amounts (<5 %) of C<SUB>18 : 0</SUB>, iso-C<SUB>13 : 0</SUB>, iso-C<SUB>17 : 0</SUB>, iso-C<SUB>17 : 1</SUB>/anteiso-C<SUB>17 : 1</SUB> B and C<SUB>16 : 1</SUB>ω6c/C<SUB>16 : 1</SUB>ω7c. Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were major polar lipids. The genomic DNA G+C content was 53.5 mol%. 16S rRNA gene sequence comparisons indicated that strain SY2<SUP>T</SUP> represents a member of the family Spirochaetaceae in the phylum Spirochaetes. Strain SY2<SUP>T</SUP> has a sequence similarity of 95.1% with Spirochaeta litoralis R1<SUP>T</SUP> and <90.1% with other members of the genus Spirochaeta. Distinct morphological, physiological and genotypic differences from the previously described taxa support the classification of strain SY2<SUP>T</SUP> as a representative of a novel genus and species in the family Spirochaetaceae, for which the name Oceanispirochaeta sediminicola gen. nov., sp. nov. is proposed. The type strain is SY2<SUP>T</SUP>(=KEMB 3001-381<SUP>T</SUP>=DSM 104770<SUP>T</SUP>=KCTC 15593<SUP>T</SUP>). Reclassification of Spirochaeta litoralis as Oceanispirochaeta litoralis comb. nov. is also proposed based on polyphasic taxonomic analyses. </P>