• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.207-214
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• 2009

The purpose of this study was to examine the influence of hypoxic exercise at head down tilt (HDT) on cardiovascular responses. Eight men ($23{\pm}2$ yrs, $176{\pm}4$ cm, and $75{\pm}8$ kg) underwent four separate exercise testing sessions; seated normoxia (SN), seated hypoxia (SH), HDT normoxia (HN), and HDT hypoxia (HH). Each participant performed the leg cycling at predetermined 40% of maximal aerobic capacity relevant to each posture for 15 min. Heart rate was higher in SH than SN and higher also in HH than SH (p<0.05). Blood oxygen saturation was lower in SH than SN (p<0.05). During resting, diastolic blood pressure and mean arterial pressure was significantly lower in HDT than seated posture (p<0.05). No differences were found between conditions in hemoglobin and hematocrit and electrolytes including, sodium, potassium, and chloride. Lactate was higher in SH than SN. In conclusion, there was no effect for cardiovascular responses to duplicate stimuli both hypoxia and posture.

• Journal of Ecology and Environment
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• v.38 no.3
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• pp.319-326
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• 2015

This study investigates the behavioral characteristics and forms of phosphorus in the sediment according to the oxygen condition (aerobic/anaerobic). In the behavioral characteristics analysis, Al-P and Fe-P concentrations were the highest among the forms of inorganic phosphorus, and therefore had the strongest impact on sorption and release corresponding to environmental condition changes. In the experimental investigation of the inorganic forms of phosphorus in the sediment according to the oxygen condition, we determined that the forms of inorganic phosphorus did not greatly affect the sorption or release reaction because the distribution ratios of the inorganic forms remained constant corresponding to changes of dissolved oxygen (DO) conditions. In contrast, the forms of organic phosphorus in the sediments affected both sorption and release. Furthermore, labile-P and moderately labile-P forms were the major mechanisms of sorption in sediment. Moderately labile-P was the greatest contributor to phosphorus release action in sediment. As environmental changes are important for the behavioral characteristics of phosphorus in sediment, the forms of phosphorus should be considered to have a greater effect, especially in the organic phosphorus case. Therefore, based on the present study results, sediment evaluation aimed at controlling internal pollutants in reservoirs should include an examination of the forms of phosphorus present, as well as the release characteristics of environmental changes, which are influential factors of phosphorus control. Further research in this field is required.

• Journal of Environmental Health Sciences
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• v.18 no.2
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• pp.67-74
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• 1992

The lab-scale biological A$_{2}$O system was applied from treating piggery wastewater highly polluted organic material which nitrogen and phosphorous are much contained relatively in conversion with other wastewater. The objective of this study was to investigate the effect of variance parameters on the treatability of this system according to operation conditions. An obtained experimental data were analysed by using principal component analysis (PCA) method. The results are summarized as follows: 1. From Varimax rotated factor loading in raw wastewater, variance of factor 1 was 36.8% and cumulative percentage of variance from factor 1 to factor 4 was 81.5% and of these was related to BOD, TKN and BOD loading. 2. In anaerobic process, variance of factor 1 was 33.5% and cumulative percentage of variance from factor I to factor 4 was 81.8% and of these was related to PO$_{4}$-P, BOD, DO and Temperature. 3. In anoxic process, variance of factor 1 was 30.1% and cumulative percentage of variance from factor i to factor 4 was 84.3% and of these was related to pH, DO, TKN and temperature. 4. In aerobic process, variance of factor 1 was 43.8% and cumulative percentage of variance from factor 1 to factor 4 was 81.5% and of these was highly related to DO, PO$_{4}$-P and BOD. 5. It was better to be operated below 0.30 kg/kg$\cdot$day F/M ratio to keep over 90% of BOD and SS, 80% of TKN, and 60% of PO$_{4}$-P in treatment efficiencies. 6. Treatment efficiencies was over 93% of BOD and SS, 81% of TKN and 60% of PO$_{4}$-P at over 20$^{\circ}$C, respectively.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.576-581
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• 1999

Effects of signal sequences, protein sizes and dissolved oxygen on the secretion of human lysozyme from a recombinant yeast were experimentally characterized. The systems consisted of Saccharomyces cerevisiae host SEY2102 that was transformed with two different plasmids. These plasmids were identical with an exception to the plasmid pMC614, which contained the native yeast MFα1 sequence and the plasmid pMC632 with the non-native rat α-amylase signal sequence. The expression of human lysozyme was controlled by the ADHI promoter. The native yeast MFαl signal sequence was more efficient than the non-native rat α-amylase signal sequence in directing the secretion of human lysozyme. Lysozyme secreted with the α-amylase signal was retained inside the cells and released to the medium very slowly, thereby causing a lower cell growth rate and a decreased product secretion rate. Lysozyme was secreted more efficiently than invertase, which is an order of magnitude bigger in molecular size compared to lysozyme, which was under the direction of the MFαl signal sequence, suggesting that protein sizes may affect the secretion efficiency. When expressed in anaerobic conditions in the medium where the ADHI promoter was derepressed, the amount of lysozyme secreted was about twice higher than that of the aerobic culture. However, the secretion rates were identical. This result showed that the dissolved oxygen level may affect the efficiency of protein secretion only, and not the secretion rate of the product protein.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.131-135
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• 2005

Under sulfur deprived conditions, PS II and photosynthetic $O_2$ evolution by Chlamydomonas reinhardtii UTEX 90 are inactivated, resulting in shift from aerobic to anaerobic condition. This is followed by hydrogen production catalyzed by hydrogenase. We hypothesized that the photosynthetic capacity and the accumulation of endogenous substrates such as starch for hydrogen production might be different according to cell age. Accordingly, we investigated (a) the relationships between hydrogen production, induction time of sulfur deprivation, increase of chlorophyll after sulfur deprivation, and residual PS II activity, and (b) the effect of initial cell density upon sulfur deprivation. The maximum production volume of hydrogen was 151 ml $H_2$/l with 0.91 g/l of cell density in the late-exponential phase. We suggest that the effects of induction time and initial cell density at sulfur deprivation on hydrogen production, up to an optimal concentration, are due to an increase of chlorophyll under sulfur deprivation.

• The Journal of Engineering Geology
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• v.20 no.1
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• pp.1-12
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• 2010

The objective of this study was to examine the hydrogeochemical and microbiological characteristics for stable maintenance of coastal LPG storage cavern. Cavern seepage water and groundwater in the vicinity of the LPG storage cavern were sampled and analyzed (February, May, August and October 2007). Groundwater samples of propane cavern showed high pHs of 8.1~12.4 due to dissolution of cement grouting materials that had been applied during the well and cavern construction. The EC values showed distinctive seasonal variation. The negative ORP indicated reduced condition. The seepage and surrounding groundwater are classified as Na-Cl type, which represents seawater effects. All of aerobic bacteria, anaerobic bacteria, slime forming bacteria and sulfate reducing bacteria were less than 500 CFU/mL, which indicated that there was no abrupt increase of bacteria in the cavern. Therefore there exist no hydrochemical symptoms to indicate unstable conditions of the cavern operation. However, regular and continuous monitoring is essentially required.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.286-290
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• 2010

C-1 compounds are observed in anaerobic sediment of high salt environments. Thus, surface sediments and waters from these environments are therefore potential habitats for aerobic methylotrophic microorganisms. The soil samples collected from saltern and tidal flat as inoculums and methanol as carbon and energy source was supplied. After subculture depending on the salt concentration, methanol oxidizing bacteria growth condition investigated, the results of methanol oxidizing bacteria can grow in salt conditions, and the maximum concentration was 20%. Analysis based on denaturing gradient gel electrophoresis of 16S rRNA genes indicates that Methelyophaga-like bacteria were dominants of methylotrophs in the enrichment culture. Quantitative PCR showed that archaeal cells were about 1-10% of bacterial cells. Additionally archaea were assumed not to be involved in methanol oxidation since bacterial antibiotics completely blocked the methanol oxidation. Our results suggest that Methelyophaga-like bacteria could be involved in C-1 compounds oxidation in hypersaline environments although those activities are sensitive to salinity above 20%.

• Applied Biological Chemistry
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• v.26 no.1
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• pp.53-57
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• 1983

Butachlor incubated for certain periods of time under the simulated, rather aerobic, rice-paddy conditions of two different soils exhibited two major degradation products. 2,6-diethyl-N-(butoxymethyl) acetanilide and a new product C in all cases, and a relativly small amount of another new product D named tentatively as 8-ethyl-2-hydroxy-N-(butoxymethyl)-3,4-dihydroquinoline in some cases. The supposedly microbial degradation seemed to proceed with incubation periods to some extent. An anaerobic incubation in the previous investigation showed 2,6-diethyl-N-(butoxymethyl) acetanilide as the major product, whereas the new product C with m/z 291 turned out to be the major one in the present condition. Structural elucidation of the products was done based on the fragmentation patterns of the given mass spectra and a possible pathway for their formation was postulated.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.214-220
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• 2004

The microcosm type wetland systems were constructed in order to treat wastewater contaminated with parathion. The microcosm reactor consisted of marsh and pond type. The experiment was carried out using batch (marsh or pond) and continuous (marsh-pond and pond-marsh type) systems. In the batch reactor, marsh-type wetland completely removed parathion in water within 8 days, while pond reactor removed 97% of parathion during the same period. During parathion degradation, the amount of 4-nitrophenol production, one of the metabolites from parathion degradation, was higher in marsh-type batch reactor. In the continuous systems, both marsh-pond and pond-marsh combination systems effectively removed parathion from water, and the production of 4-nitrophenol was also minimal. In the extraction experiment, the parathion and its metabolite were not found in the wetland soil and the plant. In order to achieve both aerobic and anaerobic conditions, the continuous wetland system combining marsh and pond type can be the alternative for the non-point source pollutants such as parathion pesticide.

• Journal of Species Research
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• v.9 no.1
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• pp.26-34
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• 2020

The phylum Bacteroidetes covers phenotypically diverse groups of Gram negative rods that do not form endospores, and currently includes 6 classes, 6 orders, 33 families and 380 genera. Members of Bacteroidetes can be aerobic and anaerobic heterotrophs, hydrogen utilizing chemolithotrophs, or methylotrophs. They can be isolated from diverse habitats including terrestrial and aquatic environments, environments with extreme physicochemical conditions, and animal and plant hosts. During a series of extensive surveys of prokaryotic species diversity in Korea, bacterial strains belonging to Bacteroidetes were isolated from various sources of aquatic and terrestrial environments. A total of 22 isolates were obtained, which represent 22 unrecorded species in Korea belonging to 14 genera of 6 families. Sixteen species among them were assigned to Flavobacteriaceae, two species were to Sphingobacteriaceae, and single species was to each of the families Bacteroidaceae, Balneolaceae, Chitinophagaceae and Cytophagaceae. At genus level, Chryseobacterium (5 species) and Flavobacterium (5 species) were the most abundant genera, and single species were obtained for the genera Bacteroides, Baloneola, Terrimonas, Dyadobacter, Aquimarina, Arenibacter, Gillisia, Gilvibacter, Salinimicrobium, Winogradskyella, Pedobacter and Sphingobacterium. The detailed descriptions of each unrecorded species are provided.