• 식물병연구
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• 제12권2호
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• pp.99-102
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• 2006

상주 지역의 곶감용 감 생산 농가의 과수원으로부터 채집한 탄저병 감염 부위로부터 90 개의 감 탄저병균 (Colletotrichum gloeosporioides)을 분리하였다. 두 종의 benzimidazole계 약제 (thiophanate-methyl, carbendazim), 3 종의 egosterol 합성 저해제 (difenoconazole, myclobutanil, tebuconazole) 및 4 종의 보호 살균제 (propineb, mancozeb, chlorothalonil, dithianon) 등 총 9 종의 살균제에 대하여 분리한 균주들의 약제반응을 조사하였다. 상용농도로 약제가 첨가된 배지에서 대조구 대비 균사생육지수를 평가함으로서 조사하였다. Carbendazim($415{\mu}g/ml$)과 thiophanate-methyl($750{\mu}g/ml$) 에 대한 반응은 각각 82%와 78%의 균주가 0.1 이하의 대조구 대비 균사생육지수를 보였다. 모든 실험 대상 균주는 myc1obutanil($40{\mu}g/ml$)과 tebuconazole ($75{\mu}g/ml$)이 첨가된 배지에서 균사생육이 완전히 억제되었으며, difenoconazole($50{\mu}g/ml$)이 첨가 배지에서는 단지 l 균주만이 0.03 의 대조구 대비 균사생장지수를 보였다. 4 종의 보호 살균제 중 propineb($1,500{\mu}g/ml$) 에 대한 감수성이 가장 높게 나타났다.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.951-970
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• 2023

This study utilized Italian ryegrass silage (IRGS) - based total mixed ration (TMR) as feedstuff and evaluated its effects on rumen fermentation, growth performance, blood parameters, and bacterial community in growing Hanwoo heifers. Twenty-seven Hanwoo heifers (body weight [BW], 225.11 ± 10.57 kg) were randomly allocated to three experimental diets. Heifers were fed 1 of 3 treatments as follows: TMR with oat, timothy, and alfalfa hay (CON), TMR with 19% of IRGS (L-IRGS), and TMR with 36% of IRGS (H-IRGS). Feeding high levels of IRGS (H-IRGS) and CON TMR to heifers resulted in a greater molar proportion of propionate in the rumen. The impact of different TMR diets on the BW, average daily gain, dry matter intake, and feed conversion ratio of Hanwoo heifers during the growing period did not differ (p > 0.05). Furthermore, the blood metabolites, total protein, albumin, aspartate aminotransferase, glucose, and total cholesterol of the heifers were not affected by the different TMR diets (p > 0.05). In terms of rumen bacterial community composition, 264 operational taxonomic units (OTUs) were observed across the three TMR diets with 240, 239, and 220 OTUs in CON, L-IRGS, and H-IRGS, respectively. IRGS-based diets increased the relative abundances of genera belonging to phylum Bacteroidetes but decreased the abundances of genus belonging to phylum Firmicutes compared with the control. Data showed that Bacteroidetes was the most dominant phylum, while Prevotella ruminicola was the dominant species across the three TMR groups. The relative abundance of Ruminococcus bromii in the rumen increased in heifers fed with high inclusion of IRGS in the TMR (H-IRGS TMR). The relative abundance of R. bromii in the rumen significantly increased when heifers were fed H-IRGS TMR while P. ruminicola increased in both L-IRGS and H-IRGS TMR groups. Results from the current study demonstrate that the inclusion of IRGS in the TMR is comparable with the TMR containing high-quality forage (CON). Thus, a high level of IRGS can be used as a replacement forage ingredient in TMR feeding and had a beneficial effect of possibly modulating the rumen bacterial community toward mainly propionate-producing microorganisms.

• 환경생물
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• 제41권3호
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• pp.256-265
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• 2023

TBT 사용이 금지된 이후, 방오도료의 방오능력을 보완하기 위하여 booster biocides를 추가하여 사용하고 있다. Booster biocides 중에서 chlorothalonil은 해양환경 내 지속적으로 유입되며 다양한 해양생물에게 심각한 독성영향을 미치고 있지만 해조류에 대한 연구는 제한적이 다. 따라서 우리나라의 주요 양식생물인 미역(Undaria pinnatifida)의 초기생활사에 chlorothalonil이 미치는 영향을 분석하였다. U. pinnatifida의 암배우체를 chlorothalonil(0, 0.03, 0.05, 0.10, 0.20, 0.40 mg L^-1)에 노출하여 생존율과 상대성장률을 분석하였다. 암배우체 생존율의 무영향 농도(NOEC), 최소영향농도(LOEC), 반수치사농도(LC₅₀)는 0.05, 0.10, 0.141 (0.121~0.166) mg L^-1이었고 상대성장률의 NOEC, LOEC, 반수영향농도(EC₅₀)은 0.10, 0.20, 0.124 (0.119~0.131) mg L^-1로 분석되었다. 따라서, 미역의 암배우체는 0.05~0.10 mg L^-1 이상의 농도에서 독성영향을 받기 시작할 것으로 판단된다. 본 연구의 결과는 chlorothalonil에 대한 U. pinnatifida 초기생활사의 건강도를 평가하기 위한 기준자료로 활용될 것으로 기대된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권2호
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• pp.137-142
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• 2005

To analyze the developmental changes in soma diameters of digastric motoneurons, wheat-germ agglutinin conjugated horseradish peroxidase (WGA-HRP) was injected into the digastric muscle and visualized the retrogradely HRP-labeled motoneurons through tungstate/tetramethylbenzidine (TMB) and following diaminobenzidine (DAB) reactions. The results obtained from Sprague-Dawley rats at postnatal days 1 (P1), 10 (P10) and 30 (P30) indicated as follows: firstly, soma diameters of digastric motoneurons showed unimodal distribution in all postnatal days examined; secondly, the period of P1 to P10 (period 1) showed about 2 times faster growth rate than that of P10 to P30 (period 2); thirdly, the smallest soma examined in each postnatal day exhibited slower growth rate with that of the largest one (increase ratio in soma diameters from P1 to P30, smallest vs. largest = 1.62 : 1.93); Finally, relative growth rates a day showed again that period 1 had faster growth rate than that of period 2. Consequently, developmental changes in soma diameters of digastric motoneurons resulted in very different growth rates between both periods. This implies that the growth of the soma is almost completing within P10 and thereafter growing slowly. The period 1 and 2 are corresponding to sucking and sucking/masticatory period, respectively. Therefore present study providing morphological changes in soma diameters of digastric motoneurons suggests that both periods and their different growth rates of the motoneurons in each period may closely be related with each other.

• Journal of Nutrition and Health
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• 제16권4호
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• pp.253-262
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• 1983

A survey was undertaken to investigate relationship between nutritional status and physical growth and behavior of school children. Dietary intakes, environmental factors, physical growth, personality, and cognitive development were measured in 323 children of 4 th and 6th grader in the urban and rural arcas. The results are summarized as follows : 1) The average intakes of the food groups and nutrients except ascorbic acid were lower in rural children. Comparing the intakes of the rural children with RDA of the Korean children, 64.0% of them in protein, 99.3% in calcium, 84.6% in iron, and 73.5% in riboflavin consumed less than 75% of RDA. Environmental factors were significantly related to the nutrient intakes 2) Height, weight, and head circumference were significantly related to the nutrient intakes. Retarded growth due to malnutrition was supposed in the $rural^{1)}$ area. 3) Some domains of personality were significantly related to nutrient intakes. 4) Environmental factors, physical growth, and nutrient intakes made independent contribution to variation in cognitive performance and their relative importance depended on the particular cognitive domain when stepwise multiple regression analyses were undertaken. Environmental stimulation was largely associated with verbal usage, and economic status and nutrient intakes with numerical reasoning. Above findings support that nutritional deprivation retards brain growth and performance on various cognitive dimensions of children. Therefore, amelioration of the several adverse social, economical, environmental influences as well as the improvement of dietary intake is required to bring about a substantial enhancement of the physical growth and the mental development of children.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.209-216
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• 2014

The efficiency of gamma irradiation (0, 1, 5, 10, 15, 20, and 30 kGy) as a sterilization method of corn samples (30 g) artificially contaminated with Fusarium moniliforme stored at normal condition ($25^{\circ}C$ with approximate relative humidity (RH) of 55%) and optimal condition ($25^{\circ}C$ with a controlled RH of 97%) was studied. The results showed that the fungal growth and the amount of fumonisin were decreased as the dose of gamma irradiation increased. Gamma irradiation at 1-5 kGy treatment significantly inhibited the growth of F. moniliforme by 1-2 log reduction on corn samples (P < 0.05). Sublethal effect of gamma irradiation was observed at 10-20 kGy doses after storage, and a complete inactivation required 30 kGy. Fungal growth and fumonisin production increased with higher humidity and longer storage time in all corn samples. This study also demonstrated that there was no strict correlation between fungal growth and fumonisin production. Storage at normal condition significantly resulted in lower growth and fumonisin production of F. moniliforme as compared with those stored at optimal condition (P < 0.05). Gamma irradiation with the dose of ${\geq}5$ kGy followed by storage at normal condition successfully prolonged the shelf life of irradiated corns, intended for human and animal consumptions, up to 7 weeks.

• ALGAE
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• 제31권4호
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• pp.363-371
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• 2016

To examine the effects of two endophytic algae, Mikrosyphar zosterae (brown alga) and Ulvella ramosa (green alga), on the host Chondrus ocellatus (red alga), culture experiments were conducted. Four treatments were made: endophyte-free (Chondrus only), endophyte-M (Chondrus + Mikrosyphar), endophyte-U (Chondrus + Ulvella), and endophytes-M U (Chondrus + Mikrosyphar + Ulvella). After 3 weeks, the relative growth rates (RGRs) of frond lengths and the number of newly formed bladelets were examined. M. zosterae formed wart-like dots on C. ocellatus fronds, whereas U. ramosa made dark spots. The RGRs of frond lengths of C. ocellatus were significantly greater in the endophyte-free and endophyte-M treatment groups than in the endophyte-U and endophytes-M U treatment groups, indicating that the growth of host C. ocellatus was inhibited more by the green endophyte U. ramosa than the brown endophyte M. zosterae. The number of newly produced bladelets was greater in the endophyte-U and endophytes-M U groups than in the endophyte-free and endophyte-M treatment groups. These results indicate that the two endophytes inhibit growth of the host C. ocellatus. The negative effects of U. ramosa on C. ocellatus growth were more severe than those caused by M. zosterae. Furthermore, U. ramosa destroyed the apical meristems of C. ocellatus, whereas M. zosterae did not. On the other hand, C. ocellatus showed compensatory growth in the form of lateral branch production as U. ramosa attacked its apical meristems.

• 한국축산식품학회지
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• 제35권1호
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• pp.108-113
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• 2015

The purpose of this study was to develop predictive models for the growth of Listeria monocytogenes in pork Bulgogi at various storage temperatures. A two-strain mixture of L. monocytogenes (ATCC 15313 and isolated from pork Bulgogi) was inoculated on pork Bulgogi at 3 Log CFU/g. L. monocytogenes strains were enumerated using general plating method on Listeria selective medium. The inoculated samples were stored at 5, 15, and $25^{\circ}C$ for primary models. Primary models were developed using the Baranyi model equations, and the maximum specific growth rate was shown to be dependent on storage temperature. A secondary model of growth rate as a function of storage temperature was also developed. As the storage temperature increased, the lag time (LT) values decreased dramatically and the specific growth rate of L. monocytogenes increased. The mathematically predicted growth parameters were evaluated based on the modified bias factor ($B_f$), accuracy factor ($A_f$), root mean square error (RMSE), coefficient of determination ($R^2$), and relative errors (RE). These values indicated that the developed models were reliably able to predict the growth of L. monocytogenes in pork Bulgogi. Hence, the predictive models may be used to assess microbiological hygiene in the meat supply chain as a function of storage temperature.

• 한국수산과학회지
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• 제44권1호
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• pp.71-77
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• 2011

The effects of temperature, light, and salinity on the growth of Costaria costata and Undaria pinnatifida juveniles were examined in laboratory cultures. In a cultivation farm, the monthly yield and density were also investigated between December and April for C. costata and between December and March in 2007 and 2008 for U. pinnatifida. The relative growth rates (RGRs) were greater at $20{\sim}60\;{\mu}mol$ photons $m^{-2}s^{-1}$ than at low ($0{\sim}10\;{\mu}mol$ photons $m^{-2}s^{-1}$) and high ($100{\sim}180\;{\mu}mol$ photons $m^{-2}s^{-1}$) irradiance levels. The optimal growth conditions for the two species were $17^{\circ}C$, 35 psu, $60\;{\mu}mol$ photons $m^{-2}s^{-1}$, and a daylength of 12 h, indicating that C. costata and U. pinnatifida have very similar growth responses to temperature, light, and salinity. However, the growth responses of the two species to various environmental factors were different; C. costata grew faster than U. pinnatifida but the latter species grew well at low salinity. The monthly yield of C. costata and U. pinnatifida increased steadily over the study period, and it was maximal in March for both species, but the yield of U. pinnatifida was greater than that of C. costata.

• 한국물환경학회지
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• 제23권6호
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• pp.837-842
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• 2007

This study was conducted to test the effect of residual Al on plankton community after dissolved air flotation (DAF) application. Growth rate of phytoplankton after DAF application ($0.37day^{-1}$) was about 2 times lower than that before DAF application ($0.70day^{-1}$). Under the condition of addition of nitrogen and phosphorus without light, growth rate phytoplankton in treatment without residual Al increased in difference with showing the negative growth rate in treatment with residual Al. Under the condition of light without addition of nutrient, growth rate of phytoplankton was no noticeable difference between the before and after DAF application. The relatively high settling rate (0.47 m/day) was observed in treatment after DAF application. Although the abundance of rotifer decreased, the abundance of copepod and cladoceran such as Daphnia galeata, Diaphanosoma sp. and Bosmina longirostris with relative higher grazing was no noticeable difference between the before and after DAF application. In the treatments before and after DAF application with zooplankton, growth rate of phytoplankton was $0.41{\pm}0.08day^{-1}$, $0.20{\pm}0.03day^{-1}$, respectively. This difference was in treatment after DAF application similar with those in treatments before and after DAF application without zooplankton. Those indicate that the filter-feeding effect of zooplankton on phytoplankton community may be not changed by residual Al after the DAF application. These results suggest that residual Al after DAF application be to improve water quality by inhibition of growth rate as well as increasing settling rate of phytoplankton.