Muscle fiber growth in olive flounder,Paralichthys olivaceus: Fiber hyperplasia at a specific body weight period and continuous hypertrophy

The objective of this study was to investigate muscle fiber growth‐related attributes, especially fiber hyperplasia and hypertrophy, and their relation to growth characteristics in olive flounder. After a conditioning period, juvenile olive flounder (214 g of initial body weight) were weighed after 0, 4, 8, 12, and 24 weeks of a feeding trial and were selected based on mean body weight at each period (G1, G2, G3, G4, and G5, respectively). During the 3.0‐fold increase in body weight (363.1–1,071 g, p < 0.001), the fiber area was increased approximately 2.2 times (p < 0.05), and the median area increased from the G1 to G5 groups (p < 0.05). The G3 group exhibited a greater fiber number than the G2 group (p < 0.05) as the G3 group exhibited a higher percentage of smaller fiber and mosaic hyperplasia. In addition, a higher percentage of centered nuclei and deoxyribonucleic acid amount in the G2 group were accompanied by an increase in fiber number in the G3 group. Therefore, the muscle growth of olive flounder was influenced by continued fiber area growth and a significant number increase by mosaic hyperplasia during a specific period (G2 to G3 groups; from 512.7 to 670.3 g).     

The characterization of polyacrylonitrile fibers stabilized by electron beam irradiation

This study investigates polyacrylonitile(PAN) fibers stabilized with various doses of electron beam irradiation (EBI) ability to produce carbon fibers. Feasibility was verified by FT-IR, the percent of gel fraction, density, DSC, XRD, and mechanical measurements. FT-IR spectra showed that the intensities of the stretching C??N bonds decreased at 2,244 cm^?1 with increasing EBI dose. This de crease was related to cyclization of nitrile groups during EBI-stabilization. The degree of cyclization was determined from the gel fraction and density tests. The gel content and density of PAN fibers stabilized by EBI increased with an increase in the EBI dose. Thermal properties were characterized by differential scanning calorimetry (DSC) and thermally activated reactions. DSC curves showed that EBI treatment influenced the quantity of released heat and the exothermic position at low temperature over a wide temperature range. The strongest diffraction peak from the PAN precursor fiber arose from the (100) plane; its stabilization index (SI) was evaluated by X-ray diffraction. The X-ray results showed that the peak intensity decreases gradually with increasing EBI dose. In addition, tensile strength decreased the EBI stabilization level.     

Alteration of helper T-cell related cytokine production in splenocytes during Trichinella spiralis infection

Infection by Trichinella spiralis takes place in two distinct phases: one is the intestinal phase and the other is the muscle phase. To evaluate alterations in cytokine production during a T. spiralis infection, we periodically assessed the cytokine production of splenocytes in mice after infection (AI). The levels of Th2-related cytokines immediately increased after the initiation of T. spiralis larval intestinal invasion (1 week AI). These early elevations in the Th2 response might be associated with the innate immune responses of intestine epithelial cells against T. spiralis larval invasion. IL-4 and IL-13 levels reached a peak prior to the initiation of nurse cell formation (2 weeks AI). Additionally, all Th17-related cytokines, except for IL-17, increased slightly until 2 weeks AI. However, expression levels for all of the Th2 and Th17-related cytokines began to decrease after the initiation of nurse cell formation and reached basal levels at 4 weeks AI, except for IL-5. At the same time, the CD4(+)CD25(+)Foxp3(+) T (regulatory T, T(reg)) cell population increased significantly in the spleen. Additionally, the number of cells in the peripheral lymph nodes increased. In conclusion, T. spiralis larva intestinal invasion induced the production of Th2 and Th17 cell-related cytokines, and the cytokines decreased with T(reg) cell-related cytokine.     

Effect of bioflocs on growth and immune activity of Pacific white shrimp,Litopenaeus vannamei postlarvae

The bioflocs technology (BFT) for shrimp production has been proposed as a sustainable practice capable of reducing environmental impacts and preventing pathogen introduction. The microbial community associated with BFT not only detoxifies nutrients, but also can improve feed utilization and animal growth. Biofloc system contains abundant number of bacteria of which cell wall consists of various components such as bacterial lipopolysaccharide, peptidoglycan and β‐1, 3‐glucans, and is known as stimulating nonspecific immune activity of shrimp. Bioflocs, therefore, are assumed to enhance shrimp immunity because they consume the bioflocs as additional food source. Although there are benefits for having an in situ microbial community in BFT systems, better understanding on these microorganisms, in particular molecular level, is needed. A fourteen‐day culture trial was conducted with postlarvae of Litopenaeus vannamei in the presence and absence of bioflocs. To determine mRNA expression levels of shrimp, we selected six genes (prophenoloxidase1, prophenoloxidase2, prophenoloxidase activation enzyme, serine proteinase1, masquerade‐like proteinase, and ras‐related nuclear protein) which are involved in a series of responses known as the prophenoloxidase (proPO) cascade, one of the major innate immune responses in crustaceans. Significant differences in shrimp survival and final body weights were found between the clear water and in the biofloc treatments. mRNA expression levels were significantly higher in the biofloc treatment than the clear water control. These results suggest that the presence of bioflocs in the culture medium gives positive effect on growth and immune‐related genes expression in L.vannamei postlarvae.     

Optimal economic fishing efforts in Korean common octopus Octopus minor trap fishery

The Korean Government is in the process of establishing a plan for managing fishing effort by setting up the maximum fishing gear usage per fishery type for the recovery of fishery resources. This will aid settlement of disputes between fishery sectors over fishing gears, and the stability of fishing business conditions. Especially in the setting up of the maximum fishing gear usage, economic standards as well as biological standards are being considered as significant factors to promote the sustainable and economically viable development of fisheries. This study is, thus, to analyze the optimal economic fishing gear usage (E_MEY) as the most economically efficient usage for the common octopus trap fishery, one of the most controversial sectors in establishing maximum fishing gear usage. Data from logbooks per trip were used for estimation of E_MEY per trip because it was considered there were limitations of data available for analyses. As a finding drawn from the analyses, the E_MEY of common octopus trap vessels per trip has to be decreased by approximately 13%. That is, reducing the trip trap usage up to the level of E_MEY can lead to the reduction of trip fishing costs, thereby resulting in increased trip profits.     

Filtration and oxygen consumption rates on various growth stages of Scapharca broughtonii spat

To investigate the effects of temperature and salinity on filtration and oxygen consumption rate of Scapharca broughtonii spat with different growth stages. This study was conducted under six different water temperatures and five different salinity conditions. The spat were divided into three groups of different shell sizes and filtration rates were estimated by Neutral red. The results showed that in all of the three groups, the highest filtration rates appeared at 20 °C, and the highest one was 1.89±0.12 L g h^?1 in the group with the lowest shell length (11.8±2.1 mm). The filtration rates in every group increased with the rise of salinity in the range from 10 to 40 g L^?1, and the highest one is 2.62±0.21 L g h^?1 in the lowest shell length group. The trends of oxygen consumption rates were similar to filtration rates. The highest rates were 0.189±0.003 mg g h^?1 at 20 °C and 0.308±0.018 mg g h^?1 at a salinity of 40 g L^?1 in the group with the lowest shell length. And the results showed that the smaller the shell size, the higher the filtration and oxygen consumption rate.     

Verifying Identities of Plant-Based Multivitamins Using Phytochemical Fingerprinting in Combination with Multiple Bioassays

Sales of multivitamins have been growing rapidly and the concept of natural multivitamin, plant-based multivitamin, or both has been introduced in the market, leading consumers to anticipate additional health benefits from phytochemicals that accompany the vitamins. However, the lack of labeling requirements might lead to fraudulent claims. Therefore, the objective of this study was to develop a strategy to verify identity of plant-based multivitamins. Phytochemical fingerprinting was used to discriminate identities. In addition, multiple bioassays were performed to determine total antioxidant capacity. A statistical computation model was then used to measure contributions of phytochemicals and vitamins to antioxidant activities. Fifteen multivitamins were purchased from the local markets in Seoul, Korea and classified into three groups according to the number of plant ingredients. Pearson correlation analysis among antioxidant capacities, amount phenols, and number of plant ingredients revealed that ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryhydrazyl (DPPH) assay results had the highest correlation with total phenol content. This suggests that FRAP and DPPH assays are useful for characterizing plant-derived multivitamins. Furthermore, net effect linear regression analysis confirmed that the contribution of phytochemicals to total antioxidant capacities was always relatively higher than that of vitamins. Taken together, the results suggest that phytochemical fingerprinting in combination with multiple bioassays could be used as a strategy to determine whether plant-derived multivitamins could provide additional health benefits beyond their nutritional value.     

Enzyme-Treated Caviar Prevents UVB Irradiation-Induced Skin Photoaging

For this research article, we investigated the protective effects of enzyme-treated caviar powder extract (CV) in ultraviolet B (UVB)-irradiated hairless mice and keratinocytes by confirming moisturizing-related factors and elasticity-related factors. UVB irradiation induced wrinkle formation, dehydration, oxidative stress, and inflammation in the dorsal skin of mice; however, these were suppressed in the CV-supplemented groups in UVB-irradiated hairless mice. Furthermore, in UVB-irradiated keratinocytes, CV treatment increased the antioxidant enzyme activities and the levels of sphingomyelin and hyaluronic acid and decreased the production of pro-inflammatory cytokines and the expression of IkB-α and p65 phosphorylation. These findings indicate that CV can directly protect keratinocytes against UVB irradiation-induced oxidative stress and inflammation. Therefore, we suggest that CV can protect against UVB-induced skin photoaging. Therefore, we suggest that caviar is effective for skin health by preventing UVB-induced skin photoaging.     

Seroprevalence of Mycobacterium avium subspecies paratuberculosis in Korean black goats (Capra hircus aegagrus)

In total, 582 sera from 116 black goat herds were analyzed by a commercially available ELISA kit to monitor the seroprevalence of Mycobacterium avium subspecies paratuberculosis (Mpt) in Korean black goats (Capra hircus aegagrus). The mean number of goats sampled per herd was 5.11, 4.66, and 5.38 for the northern, central, and southern regions of Korea, respectively. The apparent regional prevalence of Mpt was estimated at 18.2-38.2% and 4.6-15.3% for herds and goats, respectively. The Mpt-positive goats were predominantly detected in the south (n=28), compared to either the northern (n=9) or central (n=11) regions (chi=14.459, P<0.05). Our findings indicate that Mpt is prevalent among the goat population, but regional variation exists.     

Effect of Bacteriophage in Enterotoxigenic Escherichia coli (ETEC) Infected Pigs

We evaluated effect of enterotoxigenic Escherichia coli (ETEC) specific lytic phage CJ12 in ETEC infected pigs. Phage was mixed with feed at a ratio of 1:1,000 (0.1%). One week after initially providing phage mixed feed, pigs were challenged orally with 10(11) CFU of ETEC and body weight, diarrhea score, bacterial CFU and phage PFU in the feces were measured. Pigs of phage treated groups C (10(6) PFU/g) and D (10(8) PFU/g) showed more resistance to diarrhea due to ETEC infection compared to positive control group B on the third day after the initial challenge. Moreover, during the quantitation of ETEC in feces, both groups C and D showed approximately 63.92 and 60.73% reduced ETEC compared to positive control group B. Phages were successfully isolated from feces in both groups C and D during the experiment without any adverse effects, suggesting the possibility of using CJ12 as a feed additive.