The role of flatfishes in the organization and structure of the eastern Bering Sea ecosystem

We evaluated the role of flatfishes in the organization and structure of the eastern Bering Sea ecosystem using the Ecopath/Ecosim approach. As basic input data for the Ecopath/Ecosim model, we used estimates of biomass from bottom trawl surveys and age-structured population models, production/biomass (P/B) ratio, consumption/biomass (Q/B) ratio, diet composition (DC), and fisheries harvests for each component of species or species groups. We estimated the trophic level of each component, niche overlaps among flatfishes, and the impacts of competition and predation on flatfish species in the eastern Bering Sea ecosystem. Based on those estimates, we developed the tropho-dynamic structure of the ecosystem, and the model was used to simulate ecological effects of fishery exploitation patterns. No single flatfish species appeared to have a profound and uniquely important role in the organization and structure of the ecosystem. Instead, the most important component among the guild of flatfish species appeared to be yellowfin sole Pleuronectes asper, which had greater biomass than other flatfish and a relatively diverse diet among the small flatfish species. Pacific halibut Hippoglossus stenolepis, Greenland turbot Reinhardtius hippoglossoides, and arrowtooth flounder Atheresthes stomias were important keystone predators in the eastern Bering Sea ecosystem together with some groups of marine mammals and sea birds. Intra flatfish complex cannibalism was not observed, however, substantial diet overlaps were common in the flatfish guild system.     

Application of Jackfruit Latex Gum as an Eco-friendly Binder to Pigment Printing

Jackfruit latex gum was applied to pigment printing of cotton fabrics as a binder and their printing properties were compared with those of conventional pigment printing. The printing performances were influenced by the content of Jackfruit latex gum in the binder and the curing conditions. Based on a series of experiments, the pigment printing paste recipe and the process were optimized, considering color fastness, color strength, and fabric handle properties compared with those of the synthetic binder. The use of combined binder containing Jackfruit latex gum for pigment printing showed reasonable printing performances and offers an option for replacing synthetic binders, which cause adverse effect on human health and environments.     

Laparoscopy vs. laparotomy for embryo transfer to produce transgenic goats (Capra hircus)

This study was performed to produce transgenic Korean native goat (Capra hircus) by laparoscopic embryo transfer (ET) to overcome the limitations of ET performed by laparotomy. Transgenic embryos were produced by DNA pronuclear microinjection of in vivo zygotes. The recipient goats were synchronized for estrus by using an introvaginal progesterone devices as a controlled internal drug-releasing insert (CIDR) for 13 days and injection of 400 IU PMSG 48 h before removal of the insert. Embryos were transferred on day 3 and 4 after removal of the insert. Recipient goats were deprived of feed for 48 h, then suspended in a laparotomy cradle at an angle of 45°. After obtaining a sufficient pneumoperitoneum, the laparoscope and forceps were inserted abdominally through 5 mm trocar sleeves. Examination of the ovaries and uterus was performed and then 213 embryos were transferred into the oviducts via the infundibula of 76 recipient goats. To compare pregnancy rates, ET was also performed by laparotomy in 82 recipient goats. The pregnancies in the recipient goats were diagnosed by ultrasound on day 30 after embryo transfer. The pregnancy rate with laparoscopic ET was significantly higher than with ET performed by laparotomy (46.1% vs. 28.6%, p < 0.05). In addition, the pregnancy rates were compared between ovulated and non-ovulated ovaries of the recipient goats in the laparoscopic ET group. No significant difference was observed between the pregnancy rates of ovulated and non-ovulated ovaries (41.3% vs. 33.3%, p < 0.05) suggesting that ET may also be possible in non-ovulated recipients through artificial rupture of Graafian follicles. These results suggest that laparoscopic ET is a highly efficient method for the transfer of goat embryos.     

Functional efficacy analysis of Angelica gigas Nakai on chicken myoblast cells through cell‐based in vitro assay

The value‐added products in livestock industry is one of the key issues in order to maximize the revenue and to create a new business model. Numerous studies have suggested application of herbal plants as feed additives to increase health, productivity, and/or high‐quality product in livestock. In this study, the first experiment was designed to develop in vitro evaluation system by using primary chicken myoblast (pCM) cells isolated from pectoralis major of 10‐day‐old male embryos. Subsequently, to evaluate effects of Korean Danggui Angelica gigas Nakai (AGN), we optimized the concentration of AGN root extract for treatment of primary pCM cells. After the treatment of AGN root extract, we compared proliferation and differentiation capacity, and also examined the gene expression. In the second experiment, the next generation sequencing analysis was performed to compare the different patterns of the global gene expression in pCM cells treated with AGN extract. Three up‐regulated (pancreas beta cells, fatty acid metabolism and glycolysis) and one down‐regulated (adipogenesis) gene sets were characterized suggesting that the AGN extract affected the metabolic pathways for the utilization of fat and glucose in chicken muscle cells. Furthermore, we validated the expression patterns of the up‐regulated genes (GCLC, PTPN6, ISL1, SLC25A13, TGFBI, and YWHAH) in the AGN‐treated pCM cells by quantitative RT‐PCR. These results demonstrated that the treatment of AGN extract decreased proliferation and differentiation of pCM cells, and affected the metabolic pathways of glucose and fatty acids. Moreover, AGN extract derived from byproducts such as stem and leaf also showed the reduced proliferation patterns on AGN‐treated pCM cells. Taken together, pCM cell‐based in vitro assay system could be primarily and efficiently applied for evaluating the biofunctional efficacy of various feed additive candidates.     

Involvement of cytochrome P‐450 enzyme activity in the selectivity and safening action of pyrazosulfuron‐ethyl

To investigate the selectivity and safening action of the sulfonylurea herbicide pyrazosulfuron‐ethyl (PSE), pyrazosulfuron‐ethyl O‐demethylase (PSEOD) activity involving oxidative metabolism by cytochrome P‐450 was studied in rice (Oryza sativa L cv Nipponbare) and Cyperus serotinus Rottb. Cytochrome P‐450‐dependent activity was demonstrated by the use of the inducers 1,8‐naphthalic anhydride and ethanol, the herbicides PSE, bensulfuron‐methyl, dimepiperate and dymron, or the inhibitor piperonyl butoxide (PBO). Growth inhibition in C serotinus seedlings was more severe than that in rice seedlings. O‐Dealkylation activities of PSE were induced differently in rice and in C serotinus, with distinctly higher activity in rice seedlings. The induced PSEOD activities were slightly inhibited by PBO in rice seedlings, whereas they were strongly inhibited in C serotinus seedlings. Dimepiperate and dymron were effective safeners of rice against PSE treatment. Treatments with herbicide alone resulted in less induction of PSEOD activity compared with combined treatments of the herbicide and safener. PSEOD activity in rice seedlings induced with herbicide alone was strongly inhibited by PBO, whereas it was weakly inhibited in rice seedlings induced with combinations of PSE and two safeners. These results suggest that O‐demethylation by cytochrome P‐450 enzymes may be involved in the metabolism of PSE and may contribute to its selectivity and safening action. Furthermore, these results suggest the existence of a multiple form of cytochrome P‐450 in plants. © 2001 Society of Chemical Industry     

Fumigant toxicity of volatile natural products from Korean spices and medicinal plants towards the rice weevil,Sitophilus oryzae (L)

The fumigant toxicity of various volatile constituents of essential oils extracted from sixteen Korean spices and medicinal plants towards the rice weevil, Sitophilus oryzae L (Coleoptera: Curculionidae), was determined. The most potent toxicity was found in the essential oil from Mentha arvensis L var piperascens (LC₅₀ = 45.5 µl litre^?1 air). GC–MS analysis of essential oil from M arvensis showed it to be rich in menthol (63.2%), menthone (13.1%) and limonene (1.5%), followed in abundance by β‐pinene (0.7%), α‐pinene (0.6%) and linalool (0.2%). Treatment of S oryzae with each of these terpenes showed menthone to be most active (LC₅₀ = 12.7 µl litre^?1 air) followed by linalool (LC₅₀ = 39.2 µl litre^?1 air) and α‐pinene (LC₅₀ = 54.9 µl litre^?1 air). Studies on inhibition of acetylcholinesterase activity of S oryzae showed menthone to have a nine‐fold lower inhibitory effect than menthol, despite menthone being 8.1‐fold more toxic than menthol to the rice weevil. Different modes of toxicity of these monoterpenes towards S oryzae are discussed. © 2001 Society of Chemical Industry     

Effects of Dietary Supplementation of β‐hydroxy‐β‐methylbutyrate on Sow Performance and mRNA Expression of Myogenic Markers in Skeletal Muscle of Neonatal Piglets

The effects of dietary β‐hydroxy‐β‐methylbutyrate (HMB) supplementation during gestation on reproductive performance of sows and the mRNA expression of myogenic markers in skeletal muscle of neonatal pigs were determined. At day 35 of gestation, a total of 20 sows (Landrace × Yorkshire, at third parity) were randomly assigned to two groups, with each group receiving either a basal diet or the same diet supplemented with 4 g/day β‐hydroxy‐β‐methylbutyrate calcium (HMB‐Ca) until parturition. At parturition, the total and live litter size were not markedly different between treatments, however, the sows fed HMB diet had a decreased rate of stillborn piglets compared with the sows fed the control (CON) diets (p < 0.05). In addition, piglets from the sows fed HMB diet tended to have an increased birth weight (p = 0.08), and a reduced rate of low birth weight piglets (p = 0.05) compared with piglets from the CON sows. Nevertheless, lower feed intake during lactation was observed in the sows fed the HMB diet compared with those on the CON diet (p < 0.01). The relative weights of the longissimus dorsi (LD) and semitendinosus (ST) muscle were higher (p < 0.05) in neonatal pigs from the HMB than the CON sows. Furthermore, maternal HMB treatment increased the mRNA levels of the myogenic genes, including muscle regulatory factor‐4 (MRF4, p < 0.05), myogenic differentiation factor (MyoD) and insulin‐like growth factor‐1 (IGF‐1, p < 0.01). In conclusion, dietary HMB supplementation to sows at 4 g/day from day 35 of gestation to term significantly improves pregnancy outcomes and increases the expression of myogenic genes in skeletal muscle of neonatal piglets, but reduces feed intake of sows during lactation.     

Detection of Paranannizziopsis australasiensis in tuatara (Sphenodon punctatus) using fungal culture and a generic fungal PCR

AIMS: To describe the methods used at the Animal Health Laboratory (AHL, Ministry for Primary Industries) to identify Paranannizziopsis australasiensis.

METHODS: Skin biopsy samples from two adult male tuatara were submitted to the AHL in March 2014. Approximately half of each sample was processed for fungal culture and incubated on mycobiotic agar containing cycloheximide at 30°C. Following morphological examination of the culture products, DNA was extracted from suspect colonies. PCR was used to amplify the internal transcribed spacer (ITS) region of fungal rRNA using primers ITS1 and ITS4. Positive amplicons were subjected to DNA sequencing and the results were compared to published sequences. In addition, DNA was extracted from the remaining skin samples and the same PCR was carried out to compare the results.

RESULTS: After 7 days of incubation, colonies morphologically resembling P. australasiensis were observed. DNA extracted from these isolates tested positive for P. australasiensis by PCR and DNA sequencing. Samples of DNA extracted directly from the infected skin samples tested negative for P. australasiensis using the generic fungal PCR.

CONCLUSIONS AND CLINICAL RELEVANCE: Isolation and identification of P. australasiensis was carried out using a combination of fungal culture and molecular testing available at AHL. Results were available in significantly less time than in the past, when isolates had to be sent overseas. PCR and sequencing of fungal isolates is a valuable tool for identification of species that have few, if any, unique macroscopic or microscopic features to aid identification. Further sampling from captive and wild New Zealand reptiles will provide important information on the epidemiology of P. australasiensis, and the conservation and management implications for tuatara and other native reptile species.     

基于生长度日和降水量的韩国饲用玉米产量预测模型构建

本研究基于韩国不同地区的气象数据和饲用全株玉米(Zea mays)产量的历史记录数据,利用一般线性模型进行了饲用全株玉米的干物质产量预测模型的构建。作物产量等相关数据采集自韩国农业协同组合中央会饲料作物研究课题报告,气象数据采集自韩国国家气象厅网站。经过4个步骤的数据整理,最终用于模型构建的数据集包含了22年间(1988-2011年)的775个数据点。以干物质产量为因变量,通过逐步回归分析,两个气象变量被选定为构建产量预测模型的最适气象变量。进一步,通过一般线性模型,构建了包含两个选定的气象变量和以虚拟变量形式考虑进模型的栽培地域变量的韩国饲用全株玉米产量预测模型:DMY=11.298SHAGDD-3.651SHP+1 089.870+Location。其中,DMY为饲用全株玉米的干物质产量,SHAGDD为播种到收获累积生长度日,SHP为播种到收获累积降水量。通过残差分析和10折交叉验证对所构建的模型进行了检验。根据此产量预测模型,可以发现作物生长期间的温度和降水量对饲用全株玉米的干物质产量有着显著的影响。因此,确定合理的播种和收获时间以使作物获得充分的生长对确保合理的作物产量有着重要意义。此外,基于韩国夏季降水相对集中的气象条件,选择拥有较好排水性的土地和较强耐涝性的作物品种,也是确保饲用全株玉米产量的重要因素。