• Proceedings of the Korean Aquaculture Society Conference
• /
• 2003.10a
• /
• pp.126-126
• /
• 2003

Performance of a laboratory scale closed seawater recirculating aquaculture system was evaluated. Twenty-kg Korean rockfish (130 fish) with an average body weight of 153.8 g was stocked. Over 107-day culture period, fish reached final density of 51.7 kg/m$^3$ (initial density, 33.3 kg/m$^3$) on the culture tank volume basis. On a daily basis, water addition was 3.4% of the total water volume in the system. Total ammonia nitrogen (TAN)concentrations were below 1 mg/L and nitrite nitrogen (NO$_2$-N) concentrations were within the range of 1-3 mg/L on most sampling days. TAN was removedin bead and sand filters and it was removed or produced in the sedimentation basin. Basically, NO$_2$-N was removed in the bead and sand filters while it was either removed or produced in the sedimentation basin. Nitrate nitrogen (NO$_3$-N) was produced in the bead filters and removed in the sand filter and sedimentation basin. Foam fractionator performed well in the recirculating system. The maximal daily removal values for total suspended solids (TSS) and protein were 10,9 g and 1.4 g, respectively. Whole water quality parameters were within the levels commonly recommendedfor fish culture on most of the sampling days. However, further studies are needed to evaluate the commercial feasibility of this system because of the small-scale system used in present experiment. At least, present study still provides some basic information for further studies of this kind of system.

• 한국균학회소식:학술대회논문집
• /
• 2015.05a
• /
• pp.61-61
• /
• 2015

Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most destructive diseases of rice worldwide. The rice - M. oryzae pathosystem has become a model in the study of plant - fungal interactions due to its economic importance and accumulating knowledge. During the evolutionary arms race with M. oryzae, rice plants evolved a repertoire of Resistance (R) genes to protect themselves from diseases in a gene-for-gene fashion. M. oryzae secretes a battery of small effector proteins to manipulate host functions for its successful infection, and some of them are recognized by host R proteins as avirulence effectors (AVR), which turns on strong immunity. Therefore, the analysis of interactions between AVRs and their cognate R proteins provide crucial insights into the molecular basis of plant - fungal interactions. Rice blast resistance genes Pik, Pia, Pii comprise pairs of protein-coding ORFs, Pik-1 and Pik-2, RGA4 and RGA5, Pii-1 and Pii-2, respectively. In all three cases, the paired genes are tightly linked and oriented to the opposite directions. In the AVR-Pik/Pik interaction, it has been unraveled that AVR-Pik binds to the N-terminal coiled-coil domain of Pik-1. RGA4 and RGA5 are necessary and sufficient to mediate Pia resistance and recognize the M. oryzae effectors AVR-Pia and AVR1-CO39. A domain at the C-terminus of RGA5 characterized by a heavy metal associated domain was identified as the AVR-binding domain of RGA5. Similarly, physical interactions among Pii-1, Pii-2 and AVR-Pii are being analyzed.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.2
• /
• pp.201-208
• /
• 2014

This study was conducted to evaluate the ensiling characteristics and the in situ degradability of a by-product feed (BF)-based silage. Before ensilation, the BF-based mixture was composed of 50% spent mushroom substrate, 21% recycled poultry bedding, 15% ryegrass straw, 10.8% rice bran, 2% molasses, 0.6% bentonite, and 0.6% microbial inoculant on a wet basis and ensiled for up to 4 weeks. The BF-based silage contained on average 39.3% moisture, 13.4% crude protein (CP), and 52.2% neutral detergent fiber (NDF), 49% total digestible nutrient, and 37.8% physically effective $NDF_{1.18}$ on a dry matter (DM) basis. Ensiling the BF-based silage for up to 4 weeks affected (p<0.01) the chemical composition to a small extent, increased (p<0.05) the lactic acid and $NH_3$-N content, and decreased (p<0.05) both the total bacterial and lactic acid bacterial counts from $10^9$ to $10^8$ cfu/g when compared to that before ensiling. These parameters indicated that the silage was fermented and stored well during the 4-week ensiling period. Compared with rice or ryegrass straws, the BF-based silage had a higher (p<0.05) water-soluble and filterable fraction, a lower insoluble degradable DM and CP fraction (p<0.05), a lower digestible NDF (p<0.05) fraction, a higher (p<0.05) DM and CP disappearance and degradability rate, and a lower (p<0.05) NDF disappearance and degradability rate. These results indicated that cheap, good-quality BF-based roughage could be produced by ensiling SMS, RPB, rice bran, and a minimal amount of straw.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.9
• /
• pp.1291-1297
• /
• 2006

The potential of the spot urine sampling technique as an alternative to performing a total urine collection to predict the microbial nitrogen supply was evaluated in crossbred bulls. In a completely randomized design, 20 growing crossbred bulls were assigned four levels of feed intake (120, 100, 80 and 60% of voluntary dry matter intake) on diets comprised of wheat straw and concentrate mixture (50:50). After three months of experimental feeding, a metabolism trial was conducted for ten days, during which spot urine collections were performed every 6 h post feeding on days 9 and 10. The daily urinary excretion of allantoin (A) and purine derivatives (PD) decreased with the reduction in feed intake while creatinine (C) excretion remained similar in animals fed at different levels. The microbial nitrogen (MN) supply calculated from the PD excreted in total urine (35.08 to 72.08 g/d) was higher at increased levels of feed intake. PD concentration in spot urine samples had poor correlation with feed intake except at 12 h post feeding. A/C ratio and PD/C ratio in spot urine samples remained similar irrespective of sampling time and significantly (p<0.01) correlated with daily urinary PD excretion, digestible organic matter intake and dry matter (DM) intake. However, no significant differences were evident in these ratios among animals fed at levels 120, 100 and 80% of voluntary dry matter intake (VDMI) at different times post feeding. These results suggests that the spot urine sampling technique to predict the microbial protein supply is not suitable for detecting small differences in MN supply and hence, estimation of PD excreted in total urine (mmol/d) is necessary to assess precisely the MN supply in crossbred bulls.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.9
• /
• pp.1257-1261
• /
• 2006

Pleiomorphic adenoma gene-like1 (PLAGL1) encodes a zinc-finger (ZF) protein with seven ZFs of the C2H2-type which is a regulator of apoptosis and cell cycle arrest, and also regulates the secretion of insulin. In both human and mouse, PLAGL1 is a candidate gene for tumor suppressor and transient neonatal diabetes mellitus (TNDM). In this study, a 2,238 bp fragment covering the complete coding region was obtained and deposited to GenBank (accession number: DQ288899). The reverse transcriptase-polymerase chain reaction (RT-PCR) indicated that PLAGL1 was expressed almost equally in heart, liver, spleen, lung, kidney, stomach, small intestine, skeletal muscle, fat, uterus and ovary. Comparing the sequences of Large White and Meishan pigs, a C-T transition in exon 6 was found. The polymorphism could be detected by TaqI and was genotyped in five purebreds (Large White, Landrace, Meishan, Tongcheng and Bamei). Association analysis was performed between the polymorphism and carcass traits in 276 pigs of a "Large White${\times}$Meishan" F2 resource population. As a consequence, significant associations of the genotypes with shoulder backfat thickness (SFT) and internal fat rate (IFR) were observed. Pigs with TT genotype had low SFT and high IFR compared with TC or CC genotypes.

• Asian-Australasian Journal of Animal Sciences
• /
• v.8 no.3
• /
• pp.249-254
• /
• 1995

The effects of bentonite (B) on rumen protozoal population and rumen fluid characteristics of sheep fed palm kernel cake (PKC) were studied for a period of 21 days. Two groups, each comprising two sheep were fed either PKC or PKC + B ad libitum A third group was left at pasture. Rumen fluid was sampled through a rumen cannula three times daily from all animals. Palm kernel cake contained 16% crude protein, 1 % crude fat and high amounts of copper, zinc, iron and manganese. Protozoal population in the rumen fluid decreased significantly (p < 0.05) after the onset of feeding PKC or PKC + B. However, sheep given bentonite supplementation at 2% of the dietary dry matter, maintained higher protozoal densities ($15{\times}10^4/ml$) when compared to animals fed only PKC ($8{\times}10^4/ml$). With both diets, the protozoa were mainly of the small entodinia species. Animals at pasture had higher protozoal population ($47{\times}10^4/ml$) with varying species of entodiniomorphids and holotrichs. Rumen fluid pH and ammonia concentration was significantly (p < 0.05) higher in animals at pasture compared to animals fed PKC or PKC + B. Volatile fatty acid concentration was significantly (p < 0.05) lower in animals fed PKC when compared to animals at pasture. There was a shift in fermentation pattern in animals fed PKC or PKC + B towards a lower acetate; and higher propionate, isovalerate and valerate. Studies in vitro also showed the positive effect of bentonite on protozoal numbers.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.5
• /
• pp.587-602
• /
• 2011

Improved efficiency in the use of natural resources, pragmatic production systems and environmental sustainability, justified by the need for improved land use systems and increased productivity, are discussed in the context of Asian integrated systems, diversification, and issues of sustainability. The importance of these are reflected by serious inadequate animal protein production throughout Asia, where available supplies cannot match current and projected human requirements up to 2050. Among the ruminant production systems, integrated tree crops-ruminant production systems are grossly underestimated and merit emphasis and expansion. As an example, integrated oil palm- based system is an important pathway for integration with ruminants (buffaloes, cattle, goats and sheep), and provides the entry point for development. The importance and benefits of integrated systems are discussed, involving animals with annual and perennial tree crops, integration with aquaculture, the significance of crop-animal interactions, stratification of the systems, production options, improved use of forages and legumes, potential for enhanced productivity, implications for improved livelihoods of the rural poor and the stability of farm households. The advances in research and development in South East Asia highlight demonstrable increased productivity from animals and meat offtakes, value addition to the oil palm crop, sustainable development, and distinct economic impacts. The results from 12 out of a total of 24 case studies concerning oil palm over the past three decades showed increased yield of 0.49-3.52 mt of fresh fruit bunches (FFB)/ha/yr; increased income by about 30%; savings in weeding costs by 47- 60% equivalent to 21-62 RM/ha/yr; and an internal rate of return of 19% based on actual field data. The results provide important socio-economic benefits for resource-poor small farmers. Potential increased offtakes and additional income exist with the integration of goats. Additionally, the potential for carbon sequestration with tree crops is an advantage. The reasons for low adoption of the syatems are poor awareness of the potential of integrated systems, resistance by the crop- oriented plantation sector, and inadequate technology application. Promoting wider expansion and adoption of the systems in the future is linked directly with coherent policy, institutional commitment, increased investments, private sector involvement, and a stimulus package of incentives.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.6
• /
• pp.899-904
• /
• 2018

Objective: This experiment studied the effects of first feed intake time post-hatch on growth performance, nutrient apparent metabolic rate and intestinal digestive enzyme activities in broilers. Methods: Two thousand five hundred and twenty LingNan Yellow broilers were randomly allotted to seven treatments with six replicates of 60 each. The only experimental factor was the first feed intake time which was 18, 24, 30, 36, 42, 48, and 54 hours after hatching. The whole experiment lasted for 21 days. Results: During the whole period, the 30 h treatment had the best body weight and average daily gain (p<0.05), followed by the 24 h group performance optimization. Also, the 30 h group was observed to have the best apparent metabolic rate for ether extract (p<0.05) and crude protein (p<0.05) and the highest activities of amylase, lipase and trypsin in small intestine. And the 24 h group was second only to the 30 h group in terms of the above two measures. Conclusion: These results indicated that the appropriate first feeding time of LingNan Yellow broilers was 24 to 30 hours after hatching.

• IMMUNE NETWORK
• /
• v.2 no.2
• /
• pp.72-78
• /
• 2002

Background: The precise mechanism by which CTLA-4 regulates T cell immune responses is still not fully understood. Previously we proposed that CTLA-4 could downregulate T cell function by modulating a signaling cascade initiated from the T cell receptor complex. The evidence for this notion comes from our findings that CTLA-4 associated with the T cell receptor zeta (TCR zeta) chain, and hence regulated TCR zeta phosphorylation by co-associated SHP-2 tyrosine phosphatase (1). In this report, we investigated whether any other signaling molecules could be involved in the CTLA-4 signaling pathway. Methods: We have taken biochemical approaches, such as immunoprecipitation followed by autoradiography or immunoblotting, to identify the molecules associated with CTLA-4. To perform these assays, we used activated primary T cells and ectopically transfected 293 cells. Various truncation mutants of CTLA-4 were used to map the interaction site on CTLA-4. Results: We found that in addition to TCR zeta and SHP-2, a recently cloned small adaptor molecule, SAP (SLAM-associated protein), was also able to associate with CTLA-4. We identified the domain of SAP association in CTLA-4 being a motif involving GVYVKM. This motif has been previously found to bind SHP-2 through its phosphorylated tyrosine interaction with SH-2 domain of SHP-2. Indeed, co-expression of SAP and SHP-2 reduced their binding to CTLA-4 significantly, suggesting that SAP and SHP-2 compete for the common binding site, GVYVKM. Thus, by blocking SHP-2 recruitment SAP could function as a negative regulator of CTLA-4. Conclusion: Taken together, our data suggest the existence of complicate signaling cascade in regulating CTLA-4 function, and further provide evidence that SAP can act either as a positive or negative regulator depending on the nature of the associating receptors.

• IMMUNE NETWORK
• /
• v.1 no.1
• /
• pp.7-13
• /
• 2001

Currently 18 monoclonal antibodies were approved by FDA for inj ection into humans for therapeutic or diagnostic purpose. And 146 clinical trials are under way to evaluate the efficacy of monoclonal antibodies as anti-cancer agents, which comprise 9 % of clinical trials in cancer therapy field. When considering a lot of disappointment and worries existed in this field during the past 15 years, this boom could be called as resurrection. Antibodies have several merits over small molecule drug. First of all it is easier and faster in development, as proper immunization of the target proteins usually raises good antibody response. The side effects of antibodies are more likely to be checked out in immunohistomchemical staining of whole human tissues. Antibody has better pharmacokinetics, which means a longer half-life. And it is non-toxic as it is purely a "natural drug. Vast array of methods was developed to get the recombinant antibodies to be used as drug. The mice with human immunoglobulin genes were generated. Fully human antibodies can be developed in fast and easy way from these mice through immunization. These mice could make even human monoclonal antibodies against any human antigen like albumin. The concept of combinatorial library was also actively adopted for this purpose. Specific antibodies can be screened out from phage, mRNA, ribosomal library displaying recombinant antibodies like single chain Fvs or Fabs. Then the coding genes of these specific antibodies are obtained from the selected protein-gene units, and used for industrial scale production. Both $na\ddot{i}ve$ and immunized libraries are proved to be effective for this purpose. In post-map arena, antibodies are receiving another spotlight as molecular probes against numerous targets screened out from functional genomics or proteomics. Actually many of these antibodies used for this purpose are already human ones. Through alliance of these two actively growing research areas, antibody would play a central role in target discovery and drug development.