• Title/Summary/Keyword: Self-Study

Search Result 31,432, Processing Time 0.056 seconds

Evaluation and Comparison of Effects of Air and Tomato Leaf Temperatures on the Population Dynamics of Greenhouse Whitefly (Trialeurodes vaporariorum) in Cherry Tomato Grown in Greenhouses (시설내 대기 온도와 방울토마토 잎 온도가 온실가루이(Trialeurodes vaporariorum)개체군 발달에 미치는 영향 비교)

  • Park, Jung-Joon;Park, Kuen-Woo;Shin, Key-Il;Cho, Ki-Jong
    • Horticultural Science & Technology
    • /
    • v.29 no.5
    • /
    • pp.420-432
    • /
    • 2011
  • Population dynamics of greenhouse whitefly, Trialeurodes vaporariorum (Westwood), were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator (pre-programed module based simulation program developed by CSIRO, Australia). The DYMEX model simulator consisted of temperature dependent development and oviposition modules. The normalized cumulative frequency distributions of the developmental period for immature and oviposition frequency rate and survival rate for adult of greenhouse whitefly were fitted to two-parameter Weibull function. Leaf temperature on reversed side of cherry tomato leafs (Lycopersicon esculentum cv. Koko) was monitored according to three tomato plant positions (top, > 1.6 m above the ground level; middle, 0.9 - 1.2 m; bottom, 0.3 - 0.5 m) using an infrared temperature gun. Air temperature was monitored at same three positions using a Hobo self-contained temperature logger. The leaf temperatures from three plant positions were described as a function of the air temperatures with 3-parameter exponential and sigmoidal models. Data sets of observed air temperature and predicted leaf temperatures were prepared, and incorporated into the DYMEX simulator to compare the effects of air and leaf temperature on population dynamics of greenhouse whitefly. The number of greenhouse whitefly immatures was counted by visual inspection in three tomato plant positions to verify the performance of DYMEX simulation in cherry tomato greenhouse where air and leaf temperatures were monitored. The egg stage of greenhouse whitefly was not counted due to its small size. A significant positive correlation between the observed and the predicted numbers of immature and adults were found when the leaf temperatures were incorporated into DYMEX simulation, but no significant correlation was observed with the air temperatures. This study demonstrated that the population dynamics of greenhouse whitefly was affected greatly by the leaf temperatures, rather than air temperatures, and thus the leaf surface temperature should be considered for management of greenhouse whitefly in cherry tomato grown in greenhouses.

The Role of Brain and Feeding Response on Lysine Devoid Diet (Lysine 결핍에 따른 섭식반응과 뇌의 역할)

  • Kim, C.H.
    • Journal of Animal Science and Technology
    • /
    • v.44 no.2
    • /
    • pp.221-232
    • /
    • 2002
  • This study was conducted to investigate the effects of deficiency of essential amino acid in diet on feed intake and concentrations of free amino acid in plasma and brain(prepyriform cortex, PPC), and thereby to know the brain area engaged in the mechanism of feed intake regulation. In all trials, experimental diets were formulated with pure amino acid mixture to level of 15% nitrogen. Rats were trained to eat a single meal for 6 hours daily(meal feeding, 17:00-21:00). Feed intake and body weight were measured hourly on and after 7th day of feeding. In Exp. 1, feed intake and body weight were measured every hour, and the free amino acid concentrations of plasma and PPC were analysed at 0, 1, 2, 3 and 6 h on the 11th day of feeding. In Exp. 2, the complete diet was replaced with lysine devoid diet at the 11th day, and feed intake, body weight and free amino acid concentrations in plasma and PPC were samely measured on Exp. 1. In Exp. 1, feed intake on complete diet was self-sufficiented to daily feed intake level(15g/day) from the 7th day. Free amino acid concentrations of plasma and PPC at the 11th day were plateau at 1 hour after feeding. In Exp. 2, feed intake was quickly reduced by the diet replacement(P$<$0.05), and the free lysine concentration of plasma and PPC was also significantly decreased at 2 hour after feeding. However, cumulative feed intake was significantly decreased at 4 hour after feeding. These results may indicate that the concentrations of free lysine in plasma and PPC, under the condition of devoided lysine in diet, were more quickly droped than the reduction of feed intake rate. Hence, it is expected that PPC in brain might be a part of response area for limited amino acid.

Monitoring on Microbiological Contamination of Packed Ice Creams from Manufacturing Factories in Korea (국내 제조공장에서 생산된 아이스크림류의 미생물학적 오염실태 조사)

  • Heo, Eun-Jeong;Ko, Eun-Kyung;Kim, Young-Jo;Seo, Kun-Ho;Park, Hyun-Jung;Wee, Sung-Hwan;Moon, Jin San
    • Journal of Food Hygiene and Safety
    • /
    • v.29 no.3
    • /
    • pp.202-206
    • /
    • 2014
  • In this study, the bacteriological survey was examined on ice creams at manufacturing factories in Korea during the summer season of 2011. The nineteen selected among 166 samples by preliminary test were collected from 11 different manufacturing factories in four major manufacturers in May 2011. Samples from ice milk, ice creams, sherbets, and non milk fat ice creams were tested for the total aerobic bacteria, coliform bacteria, and five food borne pathogens, respectively. The results showed that the coliforms including E. coli O157:H7, Salmonella spp., Staphylococcus aureus, Clostridium perfringens, and Listeria monocytogenes were not detected on all the ice creams. The total aerobic bacteria of the packed samples examined ranged between $2.5{\times}10^3$ and $5.5{\times}10^5cfu/g$. One ice cream, two sherbets, and four ice milk samples exceeded the acceptable limits of total aerobic bacteria according to the Korean standards for ice cream ($1.0{\times}10^5cfu/g$) and others ($5.0{\times}10^4cfu/g$). The levels of these microorganisms from ice creams were higher in three original equipment manufacturers than seven self-manufacturers. Three of ten ice creams (30.0%), three of six ice milks (50.0%), and one of two sherbets (50%) exceeded the acceptable limits of total aerobic bacteria, respectively. The personnel hygiene procedures with chocolate and vanilla chip addition from the manufacturing process were the main sources of the microbial contamination of stick-bar type ice creams when being produced in a factory. Improvement of the hazard analysis critical control points (HACCP) system should be introduced into the ice cream factory to improve the microbial quality of the ice cream products in Korea.

Antioxidative Activities of Enzymatic Digests from Dried Citrus unshiu and Citrus grandis Peels (온주밀감 및 당유자 진피 효소 추출물의 항산화 활성)

  • Hyon, Jae-Seok;Kang, Sung-Myung;Senevirathne, Mahinda;Koh, Won-Joon;Yang, Tai-Suk;Oh, Myung-Cheol;Oh, Chang-Kyung;Jeon, You-Jin;Kim, Soo-Hyun
    • Korean journal of food and cookery science
    • /
    • v.26 no.1
    • /
    • pp.18-25
    • /
    • 2010
  • This study was carried out to investigate the total polyphenol and flavonoid contents and antioxidative activities of enzymatic digests from dried Citrus unshiu and C. grandis peels. The yields of digests from dried C. unshiu and C. grandis peels were high in viscozyme (a carbohydrase) and kojizyme (a protease), and enzymatic digests from dried C. grandis peels appeared highly comparable to those of C. unshiu. Total polyphenol contents were high in ultaflo (a carbohydrase) and alcalase and flavourzyme (proteases), and the digests from dried C. unshiu peels appeared high in comparison to C. grandis. Total flavonoid contents were high in ultaflo, alcalase, and water extract. DPPH radical scavenging activities appeared very high in digests from dried C. grandis peels in comparison to C. unshiu, and was the highest in viscozyme and kojizyme. The viscozyme digest displayed particularly high activity. Hydrogen peroxide scavenging activities increased somewhat with increasing amounts of digests, but displayed very high activity, more than 91%, except kojizyme the digest from dried C. unshiu peel, at 2.0 mg/mL. Alkyl radical scavenging activities increased rapidly with increasing amounts of digest, and all enzyme digests from dried C. unshiu and C. grandis peels displayed very high activities at more than 0.5 mg/mL. Hydroxyl radical scavenging activities increased rapidly with increasing amounts of digests, and all enzymatic digests from dried C. unshiu and C. grandis peels displayed relatively low activities in comparison to other activated oxygen species.

Antioxidative Activities of Dried and Fresh Citrus Peels in Jeju (제주산 감귤류 진피와 과피의 항산화 활성)

  • Hyon, Jae-Seok;Kang, Sung-Myung;Senevirathne, Mahinda;Koh, Won-Joon;Yang, Tai-Suk;Oh, Myung-Cheol;Oh, Chang-Kyung;Jeon, You-Jin;Kim, Soo-Hyun
    • Korean journal of food and cookery science
    • /
    • v.26 no.1
    • /
    • pp.88-94
    • /
    • 2010
  • This study was carried out to investigate the total polyphenol and flavonoid contents and antioxidative activities of the methanol extracts of Citrus sunki, C. unshiu and C. natsudaidai peels before and after drying. Total polyphenolic content was high in the citrus peels before drying compared to the dried peels, and highest in the order of C. sunki, C. natsudaidai and C. unchiu. On the other hand, flavonoid content was high in the dried citrus peels than in the citrus peels before drying, and was highest in the order of C. unshiu, C. natsudaidai, C. sunki, but in dried peels it was highest in the order of C. natsudaidai, C. unshiu, C. sunki. DPPH radical scavenging activity was highest in the order of C. natsudaidai, C. unchiu, C. sunki, and that in the citrus peels before drying was higher than in the dried peels. Inparticular, C. natsudaidai peels before drying showed higher activity than vitamin C in 0.5 or 1.0 mg/100 g. Hydrogen peroxide scavenging activity was highest in the order of C. unshiu, C. natsudaidai, and C. sunki in the citrus peels before drying. The dried peels were highest in the order of C. unshiu, C. natsudaidai, C. sunki at 0.5 mg/100 g, but high in order of C. natsudaidai, C. unshiu and C. sunki at more than 1.0 mg/100 g. Inparticular, all C. natsudaidai peels displayed high activity more than 87% at 2.0 mg/100 g. Clear patterns in alkyl radical scavenging activity could not be confirmed in Citrus species whether before or after drying of peels. Hydroxyl radical scavenging activity was highest in the order of C. natsudaidai, C. unshiu and C. sunki but was relatively low compared to the scavenging activity of other activated oxygen species.

Functional Properties of Soy Protein Isolates Prepared from Defatted Soybean Meal (탈지대두박(脫脂大豆粕)에서 추출(抽出)한 분리대두단백(分離大豆蛋白)의 식품학적(食品學的) 성질(性質))

  • Byun, Si-Myung;Kim, Chul-Jin
    • Korean Journal of Food Science and Technology
    • /
    • v.9 no.2
    • /
    • pp.123-130
    • /
    • 1977
  • A laboratory study was made to develop a simple and economic model method for the systematic determination of functional properties of 'Soy Protein Isolates (SPI)' prepared from defatted soybean meal. These are required to evaluate and to predict how SPI may behave in specific systems and such proteins can be used to simulate or replace conventional proteins. Data concerning the effects of pH, salt concentration, temperature, and protein concentration on the functional properties which include solubility, heat denaturation, gel forming capacity, emulsifying capacity, and foaming capacity are presented. The results are as follows: 1) The yield of SPI from defatted soybean meal increased to 83.9 % as the soybean meal was extracted with 0.02 N NaOH. 2) The suitable viscocity of a dope solution for spinning fiber was found to be 60 Poises by using syringe needle (0.3 mm) with 15 % SPI in 0.6 % NaOH. 3) Heat caused thickening and gelation in concentration of 8 % with a temperature threshold of $70^{\circ}C$. At $8{\sim}12\;%$ protein concentration, gel was formed within $10{\sim}30\;min$ at $70{\sim}100\;^{\circ}C$. It was, however, disrupted rapidly at $125\;^{\circ}C$ of overheat treatment. The gel was firm, resilient and self-supporting at protein concentration of 14 % and less susceptible to disruption of overheating. 4) The emulsifying capacity (EC) of SPI was correlated positively to the solubility of protein at ${\mu}=0$. At pH of the isoelectric point of SPI (pH 4.6), EC increased as concentration of sodium chloride increased. Using model system$(mixing\;speed:\;12,000\;r.p.m.,\;oil\;addition\;rate:\;0.9\;ml/sec,\;and\;temperature\;:\;20{\pm}1\;^{\circ}C)$, the maximum EC of SPI was found to be 47.2 ml of oil/100 mg protein, at the condition of pH 8.7 and ${\mu}=0.6$. The milk casein had greater EC than SPI at lower ionic strength while the EC of SPI was the same as milk casein at higher ionic strength. 5) The shaking test was used in determining the foam-ability of proteins. Progressively increasing SPI concentration up to 5 % indicated that the maximum protein concentration for foaming capacity was 2 %. Sucrose reduced foam expansion slightly but enhanced foam stability. The results of comparing milk casein and egg albumin were that foaming properties of SPI were the same as egg albumin, and better than milk casein, particularly in foam stability.

  • PDF

Effects of Application Levels of Fermented Cattle Manure on Forage Yield, Quality and Soil Characteristics in Orchardgrass at Jeju Area (제주지역 오차드그라스 초지에서 톱밥발효우분퇴비 시용수준이 목초의 생산성, 사료가치 및 토양특성에 미치는 영향)

  • Hwang, Kyung-Jun;Park, Nam-Geon;Park, Hyung-Soo;Lee, Chong-Eon;Kim, Nam-Young;Ko, Moon-Suk;Kim, Moon-Chul;Song, Sang-Teak
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.30 no.2
    • /
    • pp.127-134
    • /
    • 2010
  • A study was conducted to determine the effects the of cattle manure application on forage yield, quality and soil in orchard grass pasture at the experimental field of Subtropical Animal Experiment Station, National Institute of Animal Science from 2008 to 2009. The experiment was arranged in a randomized complete block design with three replications. The treatment consisted of chemical fertilizer (CF N-200 kg/ha), cattle manure 50% (basis N, CM50%), CM100% (basis N), CM200% (basis N). The dry matter (DM) yield of CM200% was the highest among the other treatments. CF showed the highest average crude protein (CP) content by 12.4% and CM50% showed the lowest content by 11.0%. Average acid detergent fiber (ADF) and neutral detergent fiber (NDF) content were 30.4 and 69.7% respectively. All treatments have narrow range of total digestibility nutrient (TDN) from 64.0% to 69.1%. But there were big difference between treatment in forage nitrate content. Changes of physical and chemical properties of soils for applications of CF 200% and CM 200% was clearly in cattle manure application. Especially, CM application in pasture increased CF application with respect to soil pH, organic matter (OM), and avaliable phosphorous ($P_2O_5$) contents of soils.

From Patients and Caregivers 119 Rescue party's Experiences for Violence in the Pre-Hospital Emergency Medical Field (환자 및 보호자로부터 구급대원이 경험한 병원 전 응급의료현장 폭력실태)

  • Shin, Sang-Yol
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.10 no.12
    • /
    • pp.3870-3878
    • /
    • 2009
  • The purpose of this study was to investigate 119 rescue party's violence experiences and to analyze their responses of violence experiences based on the pre-hospital emergency medical field. Data were collected from the self-administered survey of 226 rescue party in Jeollabuk-do area in Korea from January 1 through March 2, 2009. The data were analyzed by descriptive statistics and logistic regression analysis using SPSS Win 12.0. The results were as follows: first, all of 119 rescue unit in the pre-hospital emergency medical field reported that they got violence experiences more than once a week, and 62% of rescue team were exposed to physical violence. Patient's factors that caused violence were drug abuse or alcohol(56.2%), on the other hand rescue party's factors were shortage of human resources. Second, 42% of the respondents replied that they did not have any educational experiences for prevention and coping methods about violence within 5 years. 77.4% of those surveyed indicated that they wanted to receive specific educations which can prevent and cope with violence. Third, the mean value of total violent response scores was 2.53, and emotional response score was 3.2, social response score was 2.22, and physical response score was 2.17. Fourth, violent response score related to general characteristics proposed that physical(t=-2.08, p=o.38), emotional(t=-7.13, p=.006), and total responses(t=-4.764, p=.000) were statistically significant. And emotional(t=4.257, p=.000) and total responses(t=8.1330, p=.000) related to age were also statistically significant. Finally, among current tenure qualification scores, social response(t=9.987, p=.012) and total score(t=8.130, p=.000) were statistically significant. Between fire departments, violent response score suggested that physical(t=9.987, p=.000), emotional(t=2.433, p=.012), social(t=6.738, p=.000), and total score(t=5.943, p=.000) were statistically significant.

Experimental Models of Schizophrenia (정신분열병의 실험적 모델)

  • Cheon, Jin-Sook
    • Korean Journal of Biological Psychiatry
    • /
    • v.6 no.2
    • /
    • pp.153-160
    • /
    • 1999
  • Animal models can provide a useful tool for the study of some aspects of psychiatric disorders and their treatment. The four criteria for the evaluation of animal models of psychiatric disorders are as following : 1) similarity of inducing conditions 2) similarity of behavioral state 3) common underlying neurobiological mechanisms 4) reversal by clinically effective treatment techniques. Several animal models have been proposed for schizophrenia : phenylethylamine model, L-dopa model, hallucinogen model, cocaine model, amphetamine model, phencyclidine model, noradrenergic reward system lesion model, reticular stimulation model, social isolation model, conditioned avoidance reaction, catalepsy test, paw test, self-stimulation paradigms, latent inhibition paradigms, blocking paradigms, prepulse inhibition of the startle reflex, rodent interaction, social behavior in monkeys, hippocampal damage, high ambient pressure, and models using selective breeding. Among them, animals with bilateral lesion of the hippocampus may provide an adequate animal model for several symptoms of schizophrenia, and ketamine model can reproduce negative symptoms and cognitive deficits as well as positive symptoms of schizophrenia. In conclusion, no model of schizophrenia is entirely representative of the disease, and findings gleaned from model systems must be cautiously interpreted. Furthermore, the process of developing and validating animal models must work in concert with the process to identify reliable measures of human phenomenology.

  • PDF

The Evaluation of Feed Value and Growth Characteristics of Sasa quelpaertenisis Nakai by Horse Grazing in the Woodland of Jeju (말 방목에 의한 제주조릿대의 생육특성 및 사료 가치 평가)

  • Lee, Chong-Eon;Kim, Hyun-Cheol;Whang, Kyung-Joon;Park, Nam-Geon;Kim, Nam-Young;Oh, Woon-Young
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.30 no.2
    • /
    • pp.151-158
    • /
    • 2010
  • This study was conducted to evaluate the feed value and growth characteristics of Sasa quelpaertensis Nakai by horse grazing in the woodland of Jeju. Crude protein (CP), NDF, ADF and minerals contents at different growth stages of Sasa quelpaertensis were analyzed. The apparent digestibilities of DM, CP, NDF and ADF were determined by total collection method using 5 Jeju horses. The yield and growth characteristics of S. quelpaertensis Nakai by horse grazing were investigated. CP contents in the currentand the previous-year-sprouted leaves of S. quelpaertenisis were $16.6{\pm}1.0%$ and $12.2{\pm}1.1%$, respectively. The digestibility of DM, CP, NDF and ADF in the current-year-sprouted leaves of S. quelpaertenisis were $47.2{\pm}1.2$, $67.8{\pm}1.0$, $47.0{\pm}1.3$ and $47.1{\pm}1.1%$, respectively. The current-year-sprouted S. quelpaertenisis tended to have high nutritional values and digestibilities compared to those of the previous-year-sprouted. The dry matter yield, plant length, leaf width and density of S. quelpaertensis Nakai were clearly decreased by horse grazing. These results show that considering the feed value and growth characteristics, the natural S. quelpaertenisis Nakai can be used as a feed source for horses.