• Journal of Nutrition and Health
• /
• 제29권8호
• /
• pp.849-860
• /
• 1996

The supply of different fatty acids during the development period has significant effects. This study examined the effects of dietary $\omega$3 and $\omega$6 fatty acid compositions on phospholipids (PLs) of RBC and rat brain subcellular fractions (synaptosome, microsome, mitochondria), and on learning ability of the 2nd generation rat. Rats were fed experimental diets 3-4 wks prior to the conception. Early in the lactation period, the feeding mothers were exchanged. Diets consisted of 10% fat(by weight), which was either safflower oil('S') poor in $\omega$3 fatty acids or computer-searched mixed oil('M') with P/M/S ratio, 1/1.4/1 and $\omega$6/$\omega$3 ratio, 6.1/1. The 'S' and 'M' rats were subdivided further into SS, SM, MS & MM rats according to their lactation stauts. At 3 (weaning) & 9 wks of age, the percentage of total $\omega$3 fatty acids to their lactation status. At 3 (weaning) & 9 wks of age, the percentage of total $\omega$3 fatty acids and the ratios of $\omega$3/$\omega$6 fatty acids in PLs of RBC and brain subcellular fractions in SM and MM groups fed milk from the mixed oil-fed mothers for 2 wks tended to be higher than those in SS and MS groups respectively. In contrast, the concentrations of $\omega$6 fatty acids, especially 22:5$\omega$6 in all fractions, were significantly lower in the SM & MM groups compared to those of the SS & MS groups respectively. In contrast, the concentration of $\omega$6 fatty acids, especially 22:5$\omega$6 in all fractions, were significantly lower in the SM & MM groups compared to those of the SS & MS groups, The values for the DHA$\omega$3/22:5$\omega$6 ratios after the lactation period were markedly higher in the groups (SM & MM) which were reared by mixed oil(MO) fed mothers. In carring out Y-water maze at 9th wk of age, the SM(4.2$\pm$0.5) & MM (5.3$\pm$0.5) groups made significantly less errors compared to the SS(6.2$\pm$0.6, p<0.05 compared with SM) & MM (7.2$\pm$0.5, p<0.05 compared with MM) groups which were lactated by the safflower oilfed mothers. Therefore, by feeding a balanced fatty acid diet from the lactation period up to 9 wks of age as compared with the groups fed $\omega$3 fatty acid-deficient diet regardless of mother's diet given before parturition. The levels of DHA(synaptosome) and 22:5$\omega$3 (mitochondria) were positively correlated not only with these values in RBC but also with visual discriminating ability. The levels of DHA and 22:5$\omega$3 in RBC can, therfore, reflect visual discriminatng ability in the rat.

• ALGAE
• /
• 제34권4호
• /
• pp.289-301
• /
• 2019

Mixotrophy in marine organisms is an important aspect of ecology and evolution. The discovery of mixotrophic abilities in phototrophic dinoflagellates alters our understanding of the dynamics of red tides. In the phototrophic dinoflagellate genus Alexandrium, some species are mixotrophic, but others are exclusively autotrophic. There are differences in the ecological roles of autotrophic and mixotrophic Alexandrium in marine food webs. However, of the 34 known Alexandrium species, the mixotrophic ability of >20 species has yet to be explored. In this study, the mixotrophic capabilities of Alexandrium insuetum CCMP2082, Alexandrium mediterraneum CCMP3433, Alexandrium pacificum CCMP3434, Alexandrium tamutum ATSH1609, and Alexandrium margalefii CAWD10 were investigated by providing each species with 22 diverse prey items including bacterium-sized microbeads (1 ㎛), the cyanobacterium Synechococcus sp., algal prey species, and the ciliate Mesodinium rubrum. None of the 5 Alexandrium species fed on any of the prey items. These results increase the number of Alexandrium species lacking mixotrophic abilities to 9, compared to the 7 known mixotrophic Alexandrium species. Furthermore, the Alexandrium phylogenetic tree based on the large subunit ribosomal DNA contained 3 large clades, each of which had species with and without mixotrophic abilities. Thus, the acquisition or loss of mixotrophic abilities in Alexandrium might readily occur.

• 한국초등수학교육학회지
• /
• 제16권2호
• /
• pp.203-225
• /
• 2012

본 연구의 목적은 초등학교 수학 영재들의 수학적 창의성 신장을 위한 교육 프로그램을 개발하고 그 효과를 살펴보는데 있다. 프로그램 개발을 위해 기존의 영재교육 자료 및 관련 문헌을 분석하였으며, 이를 바탕으로 초등수학에서 가장 큰 비중을 차지하고 있는 수와 연산영역의 내용과 관련된 '연산빙고게임'을 토대로 수학영재학급의 교육 프로그램 및 교수-학습 자료를 개발하였다. 프로그램의 효과는 '창의적 산출물 평가틀'의 요소 중 수행능력을 중심으로 살펴보았다. 개발된 프로그램의 창의적 문제해결력의 효과를 살펴본 결과 개인별로 속도의 차이는 있었으나 수행 능력에 있어서 모든 학생이 점차로 향상되는 모습을 확인할 수 있었다.

• Journal of Welding and Joining
• /
• 제24권5호
• /
• pp.49-56
• /
• 2006

For laser welding in shipbuilding industry, gap bridging capability is one of the most important characteristics to achieve the high productivity and good weld quality. Recently, laser-GMA hybrid welding process is regarded as a distinctive method to overcome the tight gap tolerance with improving the productivity. In this study, the influence of process parameters on the bead formation was experimentally analyzed and the relationship between the process parameters and geometric imperfections was investigated. It was revealed that undercut, excessive weld metal, excessive penetration and incompletely filled groove were the major geometric imperfections. The optimized wire feeding and arc pressure were necessary to ensure the gap bridging ability. The approach to select the process parameters was conducted for butt welding with up to 2mm joint gap, in which the sound weld beads were generated without changing the welding speed.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2011년도 제37회 추계학술대회논문집
• /
• pp.548-553
• /
• 2011

알루알루미늄 분말과 물의 연소 특성을 연구하기 위한 장치를 고안하였다. 알루미늄 분말의 점화를 포함한 연소특성은 초기온도, 압력, 당량비등에 의존하게 되므로 이러한 인자를 변화시켜 연소환경을 적응시킬 수 있는 장치를 설계하였다. 연소 시험 장치는 메탄 연소기, 물공급장치, 알루미늄 분말 정량 공급장치, 선형 형태의 연소기 및 제어장치로 구성되어 있다. 각각의 장치들은 필요한 물질을 정량적으로 공급할 수 있는 기능을 가지고 있으며, 정해진 시험 과정에 따라 자동으로 제어될 수 있도록 설계되었다. 제작된 장치를 시운전하여 각 구성품이 정상작동하였을 때, 알루미늄 분말이 연소되는 것을 확인할 수 있었다.

• Journal of Nutrition and Health
• /
• 제32권4호
• /
• pp.369-375
• /
• 1999

Hyperthroidism in known to alter the activity of a number of enzymes involved in the catabolism of histidine to CO2. 10-Formyltetrahydrofolate dehydrogenase(EC 1.5, 1.6, 10-formyl-THE dehydrogenase) catalyzes the NADP-dependent conversion of 10-formyltetrahydrofolate to tetrahydrofolate and CO2. In previous studies, 10-formyl-THF dehydrogenase purified from rat and pig liver was coidentified with the cytosolic folate-binding protein. In this study, we investigated the effects of feeding thyroid powder (TP) and thiouracil(TU) on the folate-binding properties of 10-formyl-THE dehydrogenase, the uptake of an injected dose of [3H] folate, and the metabolism of labeled folate to pteroylopoly-${\gamma}$-glutamate in rat liver. The initial hepatic uptake(24hr) of the labeled folate dose was higher in TU-rats and slightly higher in TP-rats in controls. With longer time periods, decreased hepatic uptake of labeled folate was observed in TP-animals compared to euthroid animals, and high levels of hepatic uptake of labeled folate were maintained in TU-animals. This data shows that high levels of thyroid hormone decreased the retention of folate in rat liver. Folate polygutamate chain length was shorter in TU-rats than controls, which suggests that thyroid states do not affect the ability to synthesize pteroylpolyglutamates and that folate polyglutamate might be modulated by altered folate pool size. The ability of 10-formyl-THE dehydrogenase to bind folate in rat liver was similar in both TP-and TU-rats although dehydrogenase activity was changed by thyroid sates.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제39권1호
• /
• pp.34-38
• /
• 2019

In this study, we investigated the effect of silkworm, and its by-products on exercise endurance, muscle mass, and fatigue recovery using ICR mice model. Powders of silkworm, pupae, dongchunghacho, and silk powder were suspended in water and feed to mice for 2 weeks. The forced swimming time was increased by 4.3, 4.1 and 2.8 seconds after silkworm, pupae, and dongchughacho administration compared to DW fed group. Increases in exercise ability were achieved by difference mechanism according to feeding materials. Pupae increased muscle mass by 129% compared with the control group which may effect on elongation of swimming time. Dongchunghacho improved the plasma concentrations of fatigue markers such as creatinine, blood urea nitrogen (BUN), and D-lactate. Silkworm administration showed dual effect, the muscle mass induction (114% vs. control) and anti-fatigue (plasma creatinine, BUN, and D-lactate were 63, 75, and 78% vs. con) effect which contributed most elongated swimming time. In conclusion, silkworm and its by-products including pupae and dongchunghacho with the predominant protein and bioactive components improved muscle mass and showed anti-fatigue effect which could promote exercise performance ability.

• 한국수산과학회지
• /
• 제53권2호
• /
• pp.191-202
• /
• 2020

We evaluated the effects of dietary supplementation of phytosterol on the growth, feed utilization, immunity, digestibility, wound healing ability and disease resistance of olive flounder Paralichthys olivaceus. We conducted two consecutive feeding trials at different growth stages of the fish: EXP-1 (68.9 g) and EXP-2 (16.5 g). The experimental diets were supplemented with graded levels of phytosterol (1% ecdysteroid extracted from Achyranthis radix) at 0, 0.025, 0.05, 0.1, 0.2 and 0.4% (designated as Con, PHY0.025, PHY0.05, PHY0.1, PHY0.2 and PHY0.4, respectively). Dietary phytosterol did not significantly affect growth and cholesterol concentration. Feed utilization was higher in fish fed phytosterol-supplemented diets than in fish fed the control diet. Dietary phytosterol increased innate immunity and digestibility of protein and dry matter. Wound healing ability was also increased by the phytosterol supplementation. The survival against Edwardsiella tarda challenge was higher in fish fed low-phytosterol diets than in fish fed the control diet. The optimum dietary level of phytosterol seems to be approximately 0.05%. The results in this study indicate that the phytosterol could be used as a functional supplement in diets to improve feed utilization, immunity, digestibility and wound healing ability of olive flounder.

• ALGAE
• /
• 제38권1호
• /
• pp.39-55
• /
• 2023

Exploring mixotrophy of dinoflagellate species is critical to understanding red-tide dynamics and dinoflagellate evolution. Some species in the dinoflagellate genus Karenia have caused harmful algal blooms. Among 10 Karenia species, the mixotrophic ability of only two species, Karenia mikimotoi and Karenia brevis, has been investigated. These species have been revealed to be mixotrophic; however, the mixotrophy of the other species should be explored. Moreover, although K. mikimotoi was previously known to be mixotrophic, only a few potential prey species have been tested. We explored the mixotrophic ability of Karenia bicuneiformis, Karenia papilionacea, and Karenia selliformis and the prey spectrum of K. mikimotoi by incubating them with 16 potential prey species, including a cyanobacterium, diatom, prymnesiophyte, prasinophyte, raphidophyte, cryptophytes, and dinoflagellates. Cells of K. bicuneiformis, K. papilionacea, and K. selliformis did not feed on any tested potential prey species, indicating a lack of mixotrophy. The present study newly discovered that K. mikimotoi was able to feed on the common cryptophyte Teleaulax amphioxeia. The phylogenetic tree based on the large subunit ribosomal DNA showed that the mixotrophic species K. mikimotoi and K. brevis belonged to the same clade, but K. bicuneiformis, K. papilionacea, and K. selliformis were divided into different clades. Therefore, the presence or lack of a mixotrophic ability in this genus may be partially related to genetic characterizations. The results of this study suggest that Karenia species are not all mixotrophic, varying from the results of previous studies.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권2호
• /
• pp.198-205
• /
• 2011

This study was conducted to investigate the effect of feed types on Ochratoxin A (OTA) degradation by Korean native goats. Rumen fluid from canulated goats fed whole roughage or 50% roughage served as a source of micro-organisms. Experiments were undertaken i) to investigate OTA degradation ability in a $2{\times}4$ factorial arrangement with different feed types (100% roughage vs. 50% roughage) and rumen fluid fractions (whole rumen fluid, cells, autoclaved rumen fluid and supernatant) supplemented with OTA ii) to evaluate OTA degradation by the rumen fluid of goats fed two different diets at different time points (0, 3, 6, 9 and 12 h) of feeding iii) to isolate potential rumen microorganisms and iv) to identify elements responsible for OTA degradation. Rumen fluid from goats fed 100% roughage had higher (p<0.05) OTA degradability than 50% roughage diets. OTA degradation based on rumen fluid collection times showed that rumen fluid at 0 h showed significantly higher (p<0.05) degradability. Carboxypeptidase A (CPA) enzyme has been reported to be responsible for OTA degradation. Thus, using real time PCR, primers designed to target the CPA gene from Bacillus licheniformis could be amplified using genomic DNA from rumen fluid of goats and sequenced, thus enabling evaluation of the Bacillus population under different feeding condition and times. Our findings showed that the Bacillus population was significantly higher (p<0.05) before feeding (0 h) in animals which were fed a whole roughage diet, giving indirect evidence of OTA degradation being influenced by Bacillus sps. Thus, it can be concluded that OTA degradability is influenced by feed, feeding time and Bacillus licheniformis population.