• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.261-268
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• 1987

A green house experiment was conducted to find out the differences in the amount of biologically fixed nitrogen and kjeldahl nitrogen on the different soil texture, kinds and amounts of fertilizer nitrogen under light (photosynthetic $N_2$-fixation) and dark (heterotrophic $N_2$-fixation) condition in submerged paddy soil. The reults obtained were summarized as follows; 1. The amount of biologically fixed nitrogen per mg carbon from different organic matter was obtained as 0.13 mg in glucose, 0.09 mg in rice straw, and 0.07 mg in refused mushroom compost and barley straw under 60 days of incubation. 2. Nitrogen fixing activities were decreased with increase of fertilizer nitrogen and those tendency was pronounced more in sandy soil with application of urea than that of ammonium sulfate. 3. The application of ammonium sulfate in sandy soil under light condition was increased the photosynthetic $N_2$-fixation and the applied urea was remarkably reduced the heterotrophic $N_2$-fixation in sandy soil. The proportion of biologically fixed total nitrogen after experiment in sandy soil was obtained as 25% for dark(heterotrophic $N_2$-fixation) and 75% for light (photosynthetic $N_2$-fixation) condition. On the other hand, very similar biological $N_2$-fixing tendency was obtained between kinds of nitrogen fertilizer and two light condition in clayey soil. 4. The kjeldahl nitrogen was remarkably decreased after experiment under dark condition with application of urea than that of light condition with ammonium sulfate, and no remarkable decreasing tendency was obtained in clayey soil between two kinds of fertilizer nitrogen. 5. The high significant positive correlationship was obtained between calculated biological nitrogen fixation by acetylene reducing activity and kjeldahl nitrogen after experiment under light (y=0.8488X-5.9632, $r=0.9928^{**}$, n=21) and dark (y=0.8795X-7.1056, $r=0.9782^{**}$, n=21) condition. In this experiment condition, conversion factors of 6:1 was obtained from biological nitrogen fixation to soil nitrogen.

• Journal of Plant Biology
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• v.25 no.4
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• pp.153-160
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• 1982

The kinetics of $^{14}C$ fixation have been investigated in Anabaena flos-aquae growing on ${NH}_4+$,$NO_3-$ and $NO_2-N$ in batch cultures. Growth rate was highest with ${NH}_4+$, followed by $NO_2-$ and finally $NO_2$. The compensation intensity($I_0$) and the half-saturation irradiance($K_1$) with $K_1$ were higher than with other N sources, but the maximum C fixation rate($P_{max}$) was lower. The ($P_{max}$)/$K_1$ ratio, which is analogous to quantum efficiency at low irradiance ranges, was also lower with $N_2$. All these parameters except $K_1$ decrease with culture age, or decreasing growth rate. Since $^{14}C$ uptake measures net photosynthesis, the higher values of $I_0$ and $K_1$, and the low values of $P_{max}$/$K_1$ ratio with $N_2$ appear to be related to the high energy demand of $N_2$fixation. They may also be related to the lox maximum growth rate with $NO_2-N$.

• Journal of Plant Biology
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• v.30 no.3
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• pp.205-213
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• 1987

Soybean, inoculated with effective Rhizobium japonicum 110, were grown by sand culture with nutrient solution containing either of 0, 1, 3, 10 or 30mM NO3-/l, and analyzed growth characteristics, NR activity, N2-fixation activity, and changes of ureide contents during the growing period. The amount of nodule formation decreased abruptly by nitrate treatment, the maximum nodule dry weight was 1.59, 1.05, 0.78, 0.09 and 0.008 g plant-1, respectively for each treatment on the 98th day. Specfic activity of N2-fixation showed the maximum rates of 140, 101, 37, 5 and 2.2 nM dw.mg-1.hr-1, respectively for each treatment in the earlier growth period. The maximum acetylene reduction activity on the 98th day after sowing was 81.5, 35.3, 14.3, 0.1 and 0.0045 $\mu$M C2H4 plant-1.hr-1, respectively for 0, 1, 3, 10 and 30 mM of NO3- gradients. Nitrate reduction activity increased along with nitrate gradients, and decreased abruptly with age. Relative abundance of ureides in plant organs was high in reproductive growth, and showed the maximum value in fully symbiotic dependent plant. Relative abundance of ureides in stem is a useful indication for the evaluation of nitrogen fixation in nodules of symbiotic plant.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.4
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• pp.433-438
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• 2011

Purpose: To investigate the proper distance from patient to target when measuring refractive error using open view target type auto-refractor(OVTAR), it was compared refractive errors between by OVTAR using N-vision-K5001 auto-refractor and internal fixation target type auto-refractor(IFTAR) using Canon auto-refractor. Methods: 21 subjects(42 eyes) aged 22.2(${\pm}$3.4) years old who had over 1.0 of corrected visual acuity and no ocular disease were participated for this study. Noncycloplegic measurements of refractive error were performed using a IFTAR(RK-F1, Canon, Japan) and an OVTAR(N-vision-K5001, Shin-nippon, Japan). The distances from subjects to targets in using the open the view target type auto-refractor were 1 m, 3 m, 4 m and 6 m. The refractive errors were compared between by IFTAR and by 1 m, 3 m, 4 m and 6 m target distances respectively using OVTAR. Results: At 1 m fixation distance the mean of refractive errors for total subjects was not significantly different between by OVTAR(-2.75${\pm}$1.84 D) and by IFTAR(-2.95${\pm}$2.04 D)(p=0.06). However at 3, 4 and 6 m fixation distance refractive errors by OVTAR were significantly lower myopic refractive errors than by IFTAR(p<0.05). Conclusions: The distance from subject to fixation target is needed over 3 m for the measurement of refractive error using OVTAR even not to 5~6 m distance.

• Journal of Veterinary Science
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• v.21 no.6
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• pp.90.1-90.11
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• 2020

Background: Mandibular fractures are common in camels, leading to considerable economic losses. This study explored methods of improving mandibular fractures repair, adjuvant with interdental wire, or bone plate fixation. Autologous bone marrow (BM) injection enhances osteogenesis and rapid healing. Objectives: To investigate the effect of autologous BM aspirate as an adjuvant treatment for repairing mandibular fractures in camels with interdental wire, or bone plate fixation. Methods: Thirty dromedary camels aged 5-8 years and of both sexes were randomly divided into 4 treatment groups: group 1 (n = 10) treated with stainless steel wire fixation and BM injection at the fracture line, group 2 (n = 10) treated with plate fixation and BM injection at the fracture line, group 3 (n = 5) treated with stainless steel bone wire fixation and placebo saline injection at the fracture line, and group 4 (n = 5) treated with plate fixation and placebo injection at the fracture line. The mandibular fractures were followed weekly for 12 weeks postoperatively to assess improvement and healing based on clinical evaluation, radiographic union scale, and bone turnover markers (i.e., bone alkaline phosphatase, osteocalcin, pyridinoline, and deoxypyridinoline). Results: Compared to other groups, elevated bone turnover markers in group 1 were demonstrated (p < 0.05) on the seventh postoperative day. Likewise, compared to other groups, both clinical findings and radiographic union scale significantly improved (p < 0.05) in group 1 on the 56th postoperative day. Conclusions: BM aspirate has a promising beneficial osteogenic effect on mandibular fracture repair in camels, most notably when combined with interdental wire fixation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.50-57
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• 2008

Winter season cultivation of rye as green manure for soybean have been a favorite with farmer because it could remove a risk of injury by continuous cropping and increase N uptake and yield of soybean. Effects of rye green manure on soybean N uptake, $N_2$ fixation and yield were investigated with $^{15}N$ as pot experiment in greenhouse in 2004 and field in 2005, respectively. The N derived from N fertilizer ($^{15}N$) in rye green manure increased with increasing of N fertilizer rate compared to N derived from soil. N uptake and DM yield of soybean at the pot with paddy soil was higher than those at the pot with upland soil mainly due to the increase of N uptake from paddy soil. Total $^{15}N$ recovery in soil was higher at rye green manure than no green manure because $^{15}N$ applied to rye plant was remained highly as soil organic N compared to chemical N fertilizer. $^{15}N$ recovery in soybean plant increased in proportion to amounts of N fertilizer applied to rye. The N fractions from $N_2$ fixation of soybean plant at the pot experiment in 2004 ranged from 92% to 95%, on the other hand those in field experiment in 2005 ranged from 82% to 84%. Estimation of amount of $N_2$ fixation was not different between Difference method and $^{15}N$ method in 2004 and 2005.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.188-194
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• 1983

A Pot experiment was conducted to find out the effects of NPK fertilizers and soil amendments on the symbiotic nitrogen fixation and yield of soybean inoculated with Rhizobium japonicum in newly reclaimed upland soil with very low fertility. The results are summarized as follows; 1. Application of PK fertilizer and soil amendments such as lime, and rice straw in combination with micronutrients (Zn, B, Mo) increased the amounts of symbiotic $N_2$ fixation in soybean. 2. The inoculation of Rhizobium japonicum with application of soil amendments increased the yield of soybean by 4% to 10% due to enhanced $N_2$ fixation. 3. In case of improvement of newly reclaimed hilly soil in order to obtain the high yield of soybean, simutaneous application of soil amendments with inoculation of R. janconican should the highest yield.

• Journal of Korean Neurosurgical Society
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• v.37 no.5
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• pp.345-349
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• 2005

Objective: Anterior screw fixation provides the best anatomical and functional results for type II odontoid process fracture (type II-A, II-N, and II-P) with intact transverse ligament. The purpose of this study is to evaluate the usefulness of the 4.5mm diameter, cannulated Herbert screw in anterior screw fixation. Methods: From Jan. 2003 to Feb. 2004, consecutive 10cases of type II odontoid process fractures were treated with anterior screw fixation using a Herbert screw. The Herbert screw has double threads, with different pitches on the distal and proximal ends. It has no head, so it can be inserted through articular cartilage and buried below bone surface. It was originally developed for treating scaphoid fractures. Results: There were 8male and 2female patients whose ages ranged from 15 to 67years (mean 42.1years). The fracture type was type II-A in 4patients, II-N in 3 patients, and II-P in 3 patients. The fracture line was oblique downward and backward in 6cases, oblique downward and forward in 1 case, and horizontal in 3cases. The range of follow-up was 5 to 18months (mean 12months). Bone fusions were achieved in all cases without any instrumental failures or postoperative complications. Conclusion: The Herbert screw is very useful in anterior fixation for type II odontoid process fracture. This series showed successful results also in type II-A odontoid fracture when treated with the Herbert screw, but further more studies are required.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.4
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• pp.277-283
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• 1982

A series of experiments were conducted on procedures of $N_2$ fixation measurements with soybean (Glycine max. L.) root nodules by acetylene reducing assay and estimation of amounts of $N_2$ fixed by soybean root nodules grown in the pot. The results are summarized as follows; 1. In case of nitrogen fixing activities were determined by means of acetylene reducing method, more appropriates results were obtained with direct determination of root nodules which was adhering from root under 2 hours after incubation, while more fluctuated data was obtained with root nodules determined under separated conditions. 2. The weight of soybean nodules was linearly increased from 17 days to 55 days after planting, whereas, the amounts of $N_2$ fixation from soybean nodules were Peaked at 38 days after planting, and declined thereafter. 3. When calculated upon the basis of the amounts of $N_2$ fixed as measured by acetylene reducing activities in single soybean plant, it was found that the average amount of symbiotic $N_2$ fixation falls in the range of 80 kg N per ha.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.291-295
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• 2019

BACKGROUND: Mixed cropping of hairy vetch and Barley is widely used as a green manure for reducing chemical fertilizers while maintaining soil fertility in paddy soil. We investigated the effect of Molybdenum (Mo) fertilizer on vetch N₂ fixation, biomass production and transfer N from vetch to barley under a hairy vetch-barley mixed cropping system. METHODS AND RESULTS: The barley and hairy vetch were sowed at a rate of 135 and 23 kg/ha, respectively, without chemical fertilizer application but with Mo fertilizer at 0, 0.5, 1.0, 2.0, and 4.0 kg/ha as a treatment. The percentage of hairy vetch N derived from air N₂ fixation (%Ndfa) and N transfer from hairy vetch to barley (%Ndfv) was determined by the ¹⁵N natural abundance method. Although application of Mo at 2.0 kg/ha significantly increased biomass of both barley and hairy vetch, the biomass was decreased at application of Mo 4.0 kg/ha. At the application of Mo 2.0 kg/ha, the percentage of Ndfa and Ndfv was 81.7 and 53.9, respectively, which are significantly higher than that of the treatments without Mo. CONCLUSION: These results highlight that application of Mo fertilizer can be an effective measures to improve N fixation in hairy vetch and biomass production in both barley and hairy vetch.