The objective of this study was to evaluated the efficiency on sperm cryosurvival and ability of in vitro fertilization using Triladyl and Lactose Egg-Yolk(LEY) as extenders for cryopreservation of separated sperm by 65% percoll in miniature pig. Sperm viability was measured with SYBR-14/PI double stained sperm by flow cytometry. Ability on embryo cleavage rate and blastocyst development were observed by in vitro fertilization after frozen-thawing of sperm separated by 65% percoll. The experimental groups were designed that separated sperm by 65% percoll with Triladyl (ST) or LEY(SL) and unseparated sperm with Triladyl(UT) or LEY(UL) for cryopreservation. As a results, the viability was significantly(p<0.05) higher in ST(55.1%), SL(63.1%), UL(58.8%) than UT(38.2%) group. Sperm viability in SL(63.1%) group was significantly(p<0.05) higher than other experimental groups. On the other hand, embryo cleavage rate was significantly(p<0.05) higher in ST(79.1%), SL(83.2) than UT(74.1%) and UL(75.7%) groups at 96h after in vitro fertilization. Blastocyst development was also significantly(p<0.05) higher in ST(21.5%), SL(20.9%) than UT(17.0%) and UL (18.8%) groups. In conclusion, cryopreservation of miniature boar sperm separated by 65% percoll were beneficial to viability and capacity on in vitro fertilization.

The objective of this study was to evaluate the sperm liquid storage diluted with Brine Mineral Water (BMW) in miniature pig. Therefore we performed to find optimal concentration of BMW. The ejaculated semen from miniature pig was collected by gloved-hand method. The collected semen was diluted with dilution solution (Mulberry Ⅲ; modified-Modena B) which BMW was added. Concentration of BMW was 0, 2.5, 5, 7.5, 10 and 12.5% in dilution solution. The diluted semen was preserved at 17℃. Sperm ability was estimated by viability, capacitation acrosome reaction using chlortetracycline (CTC), hypoosmotic swelling test (HOST), morphologic abnormality. The diluted semen was observed for 7 days. The viability was significantly measured higher at 2.5% concentration of BMW than other groups (p<0.05). The AR-pattern of CTC analysis was significantly measured lower at 12.5% concentration of BMW than other groups (p<0.05). However, abnormality was not significantly different among all the groups (p<0.05). In conclusion, viability of sperm was the highest at 2.5% concentration of BMW but BMW had a negative effect on HOST, capacitation and acrosome reaction in sperm of miniature pig.

The objective of this study was to evaluated the efficiency of sperm cryosurvival using each extenders Triladyl and LEY containing egg yolk to the cryopreservation of separated sperm by percoll in miniature pig. The ejaculated semen from miniature pig was separated by 65% percoll and un-separated sperm as a control before freezing. The freezing of diluted semen added with Triladyl containing egg yolk and LEY solution (solution Ⅰ: 11% Lactose or Triladyl + egg yolk; solution Ⅱ: solutionⅠ + glycerol + OEP). Analysis of sperm ability was estimated by viability, capacitation acrosome reaction using chlortetracycline (CTC) the morphologic abnormality and hypoosmotic swelling test(HOST). The groups were designed that as separated sperm by Percoll with Triladyl(ST) or LEY(SL) for cryopreservation. And unseparated sperm with Triladyl(UT) or LEY(UL). As a results, the viability was higher significantly(p<0.05) in ST, SL, UT than UL extender. The morphologic abnormality was measured significantly (p< 0.05) lower in ST than other extenders. The AR-patterned in CTC analysis was measured significantly(p<0.05) lower in SL and UL than other extenders. In conclusion, using Triladyl extender resulted in viability and morphology of separated sperm by percoll that were effective than using LEY extender, but it resulted in capacitation acrosome reaction was lower than using LEY extender.

Subterranean termiteslive in the soil and wood that is in contact with soil. They have to discover food by constructing underground tunnel networks. Once the food is discovered and connected to the galleries, one important aspect of the foraging behavior is the food transfer by individual termites moving within the existing tunnels that lead to multiple existing food sources. In order to reveal how much the tunnel network is reliable to the food transfer efficiency, we used a lattice model suggested by Lee et al. (2006), which is capable of simulating the tunnel networks of Coptotermes formosanus and Riparius flavipes. After constructing the simulated tunnel networks, we randomly distributed food particles on the tunnel networks and then computed path entropy for the networksby selecting and evaluating the shortest paths from encountered food particles to the nest. The path entropy measured the degree of reliability of the networks for the food transfer entropy. Simulation results showed that path entropy between the simulated networks of C. formosanus and R. flavipes was significantly different due to the combinational effects of the network components such as the number of primary tunnels and the branching probability. We discussed the meaning of the results in relation to termite foraging efficiency.

Subterranean termites excavate tunnels for searching and transporting food below the ground, which in turn causes complicated tunnel networks. In the present study, we explored the connectedness of the networks by using spectral graph theory. In the theory, tunnel network pattern can be constitutively expressed by the Laplacian matrix, and among the set of all eigenvalues of the matrix, the second eigenvalue directly reflects the degree of the connectedness. We constructed the simulated tunnel networks for Coptotermes formosanus and Riparius flavipes by the use of a lattice model suggested by Lee et al., (2006) and computed their connectedness. The results showed that the values of the connectedness between the two species were statistically-significantly different. We briefly discussed the results in relation to foraging efficiency.

Subterranean termites construct complicated tunnel network for foraging below the ground. Thus, they often encounter a number of tunnel intersections during their moving from place to place in the network. In order to understand how termites respond to the intersections, we artificially excavated two tunnels intersected with 90° degree in soil-filled arenas. The two tunnels had the width of W1 and W2 (=2, 3, and 4mm), respectively. We systematically observed the response behavior of advancing termites to the intersection with the combination of W1 and W2, (W1, W2). For (W1, W2)=(2, 2) and (3, 3), the advancing termites passed the intersection without directional changes because it was difficult for termites to bend their body to change their moving direction due to the small-sized width. For (W1, W2)=(4, 4), the termites statistically-equally chose the three directions, left, right, and straight, which was due to the fact that the intersection provided enough space for termites to bend. For (W1, W2)=(2, 3), (2, 4), and (3, 4), termites, advancing in narrower tunnels, tended considerably to turn right or left, while termites, advancing in wider tunnels, were favorably inclined to go straight. These results can be understood by considering the relationship between termite body length and tunnel width as explained for the cases of W1=W2. In addition, we briefly discussed our findings in relation to termite foraging efficiency.

Subterranean termites construct underground tunnels, tens to hundreds of meters in length, in order to search for and transport resources. Diverse soil conditions surrounding the tunnels, such as soil pores and differing moisture concentrations, may cause different sized- and shaped-irregularities in the tunnels. To understand how individual termites respond to the irregularities, the present study monitored the movement of termites, Coptotermes formosanus Shiraki, in artificially excavated tunnels with rectangular irregularities of varying sizes in twodimensional sand substrates. Termites tunneled at some of the irregularities and not at the others. The tunneling or non-tunneling behavior resulted from four different responses. The non-tunneling response may result from a behavioral adaptation that allows termites to avoid wasting energy that may be used in foraging.

This study was conducted to investigate stimulatory effect of epidermal growth factor (EGF) on nuclear maturation and the expression level of EGF-receptor (EGFR), GM-130 (a marker of Golgi apparatus), transport protein Sec61 subunit beta (Sec61β), and coatomer protein complex subunit gamma 2 (COPG2) in porcine oocytes. The cumulus-oocyte complexes were collected from follicle with 3-6 mm in diameter. They were incubated in medium with/without EGF for 22 h (IVMⅠ) and subsequently incubated hormone-free medium with/without EGF for 22 h (IVMⅡ). Nuclear maturation state was checked by aceto-orcein stain. Protein expression of EGFR, GM-130, Sec61β, and COPG2 were measured by immunofluorescence. In results, nuclear maturation of oocytes in EGF non-treated oocytes were significantly lower than EGF-treated groups at IVMⅠ or IVMⅡ stage (P<0.05), whereas maturational rate in EGF treatment groups at both of IVM stage was higher in among the all treatment groups (P<0.05). EGFR, GM-130, Sec61β and COPG2 were expressed in the cytoplasm of oocytes. Especially, GM-130 and EGFR were strongly expressed, but Sec61β and COPG2 were weakly expressed in cortical area of cytoplasm. The protein level of GM-130, Sec61β, and COPG2 were significantly higher in the EGF-treated groups (P<0.05). However EGFR was no difference between non EGF-treated groups and control. In conclusion, EGF plays an important role in the systems for oocyte maturation with endoplasmic reticulum and Golgi apparatus. In addition, the protein levels of Sec61β and COPG2 could be changed by EGF in the porcine oocytes during maturation.

A series of experiments was conducted to identify the potential of five phytoplankton species as standard test species for marine ecotoxicological tests. The candidate phytoplankton species are Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, and Tetraselmis suecica. Salinity tolerance and sensitivity on potassium dichromate as a reference material were identified. Toxicity of eleven ocean-dumped sewage sludges and four red tide expellent extracts were estimated by the inhibition of population growth rates (PGR) of marine diatom S. costatum. While most species revealed relatively weak tolerance on salinity, T. suecica demonstrated the highest salinity tolerance ranged from 5～35 psu and the others 15～35 psu. H. akashiwo revealed the highest sensitivity as 72h IC50=0.76mg/L and T. suecica the lowest as 72h IC50=8.89mg/L on potassium dichromate. Sludge extracts from industrial waste, domestic sewage and livestock farm waste sludge showed high toxicity as 72h IC50<2% and lowest toxicity from filtration bed sludge as 72h IC50=30.50%. NOEC (No Observed Effective Concentration) of sludge extract ranged from <0.4% to 1.6% and this indicated high phytotoxicity of ocean dumped sewage sludge. The test sensitivity of phytoplankton PGR inhibition was much higher than those of marine rotifer Brachionus plicatilis mortality test and bioluminescent inhibition test by marine bacteria Vibrio fischeri, and comparable with the sea urchin (Strongylocentrotus intermedius) fertilization test. As a result the phytotoxicity test using phytoplankton PGR inhibition (IC50) must be a useful tool for marine phyto-toxicological evaluation of ocean dumped materials.