The purpose of this study is to optimize the extraction conditions (time, pH, and temperature) for water-soluble dietary fiber (SDF) and solids from Opuntia ficus-indica (OFI) stems and to evaluate the functionality of the optimized extract. The maximum extraction yield was obtained when 100% distilled water was used, indicating that ethanol hampered the extraction. The extraction yields were lower at higher temperatures and lower pHs. The maximum extraction of SDF (27.92%) and solids (5.6 g) was achieved with a 7-h extraction at 50oC and pH 7.0, with desirability being 0.958. The stem extract obtained under the optimum extraction conditions had an antioxidant capacity of 118.10 mg vitamin C equivalents (VCE) using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. In a medium containing 30% extract, the growth of E. coli was reduced by 34%, while that of B. cereus was reduced by 23%. These results suggest that OFI stems can be used as a functional resource.

The purpose of this study was to utilize the stem of Opuntia ficus-indica and to optimize the extraction conditions and standardize extract process for water soluble dietary fiber and solid. Extraction process was optimized by applying various conditions such as pH, ethanol concentration, extracting temperature and time. Maximum extraction yield for water soluble dietary fiber and solid were obtained using 100% water, indicating that ethanol hampered extraction. Also, extraction was unstable with higher heat, longer extraction time, and low acidic conditions. Maximum extraction of water soluble dietary fiber (27.92%) and solid (5.6 g) were obtained at 50°C, pH7, and 7 hr extraction time. Extract had antioxidant capacity at 1105.98 mg vitamin C equivalents (VCE) on ABTS assay and 118.10 mg VCE on DPPH assay.

Opuntia is a cactus with fruits and is also called prickly pear. Extraction process of water soluble fiber from opuntia stem powder was optimized by applying various conditions such as ethanol concentration, temperature and pH. Fiber extraction was highest in 0% ethanol and lowest in 100% ethanol, indicated that hot distilled water extraction produced maximum water soluble fiber. Among temperature range from 50 to 90°C, water soluble fiber was extracted mostly at 50°C and leastly at 90°C, showing decrease in fiber with increase in temperature. On the other hand, pH higher than 7 did not show any significant difference in fiber extraction, while fiber extraction decreased in lower pH 7. Conclusively ethanol hampered extraction of water soluble fiber from opuntia stem powder and extraction was not stable with higher heat and low acidic condition.

Recent discovery of 2M⊙ neutron stars in white dwarf-neutron star binaries, PSR J1614-2230 and PSR J0348+0432, has given strong constraints on the maximum mass of neutron stars. On the other hand, all well-measured neutron star masses in double neutron star binaries are still less than 1.5M⊙. These observations suggest that the neutron star masses in binaries may depend on the evolution process of neutron star binaries. In addition, recent works on LMXB (low-mass X-ray binaries) provides us the possibility of estimating the masses and radii of accreting neutron stars in LMXBs. In this talk, we discuss the implications of recent neutron star observations to the neutron star equation of states and the related astrophysical problems. For the evolution of neutron star binaries, we also discuss the possibilities of super-Eddington accretion onto the primary neutron stars.

Recently, a rapid movement of agricultural products with an extensive international trading and climate change have led to an increased attention to nematodes as having regulatory significance. With the increase of global dispersal of pests, new diagnosis methods are required for a rapid and reliable species and/or biotype identification to restrict introduction of the pests. Recently, novel molecular diagnostic techniques provide clues to solve taxonomic problems associated with conventional species identification. In this articles, we proposed various molecular diagnostic techniques to complement the limitation of morphological taxonomy.

We amplified D1 and D3 expansion segments of the 28S ribosomal RNA from 10 Suanguina moxae populations found in Korea. The amplification of the D1-D3 expansion segments of 28S gene of all populations tested produced a single PCR product approximately 1.03kb in size, suggesting the lack of D1-D3 expansion region size polymorphism among populations. The secondary structure model of 28S expansion segments D2 and D3 for Subanguina Moxae was predicted based on free energy minimization with comparative sequence analysis and new sequence alignment was conducted based on predicted secondary structure model. The predicted model was compared with previous predicted models of plant and animal parasite nematode. This predicted secondary structure model will provide valuable information to allocate positional sequence homology and reconstruction of reliable phylogenetic trees.

The intensive meteorological observations including pibal balloon at Ungcheon, airsonde and 10m meteorological tower observations at Gulup-Do, where are located in the western coastal region, are taken to investigate the characteristics of the upper and lower atmospheric structure and the local circulation pattern during the period of 17 to 22 September 1996. The diurnal variations of weather elements(i.e, air temperature, humidity, pressure, and wind speed) at Gulup-Do are analyzed and discussed with those at four inland meteorological stations. The vertical profiles of wind vector, orthogonality(Ω), and shear obtained from the pibal observations are also presented to examine the change of wind structure according to the synoptic-scale pressure system`s movement. The diurnal temperature changes at Gulup-Do are more sensitive than that of inland meteorological stations in case of the inflow of southwesterlies but are not dominant due to the ocean effect under the influence of relatively cold northerlies. A well defined mixed layer is developed from the 500m to the maximum 1700m with a significant capping inversion layer on the top of it. It can be found from the vertical profiles of wind vector that the wind become generally strong at the interface heights between cloud layers and non-cloud layers. The maximum wind shear is appeared at the height where the variation of wind direction induced by the passage of synoptic-scale pressure system is accompanied with the increase of wind speed. Based on the wind orthogonality, the change of wind direction with height is more complicated in cloudy day than in clear day. In case of a fair weather, the change of wind direction is showed to be at around 2㎞

The characteristics on the transtion probabilities and periodicity for the daily precipitation occurrence in Korean peninsula are investigated by applying the Markov chain properties to daily precipitation occurrence. In order to examine the responses of Markov Chain properties to the applied period and their magnitudes, three cases (Case A: 1956∼1985 at 14 stations, Case B: 1965∼1994 at 14 stations, and Case C: 1985∼1994 at 63 stations) are considered in this study. The transition probabilities from wet day to wet day for all cases are about 0.50 and in summer, especially July, are higher. In addition, considering them in each station we can find that they are the highest at Ullung-do and lowest at Inchon for all cases. The annual equilibrium probabilities of a wet day appear 0.31 in Case A, 0.30 Case B, and 0.29 Case C, respectively. This may explain that as the data-period used becomes shorter, the higher the equilibrium probability is. The seasonal distributions of equilibrium probabilities are appeared the lowest(0.23∼0.28) in winter and the highest(more than 0.39) in spring and monthly in July and in October, repectively. The annual mean wet duration for all cases is 2.04 days in Case A, 1.99 Case B, and 1.89 Case C, repectively. The weather cycle obtained from the annual mean wet and dry duration is 6.54∼6.59 days, which are closely associated with the movement of synoptic systems. And the statistical tests show that the transitions of daily precipitation occurrence for all cases may have two-state first Markov chain property, being the stationarity in time and heterogeneity in space.