• Korean Journal of Plant Resources
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• v.35 no.2
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• pp.192-200
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• 2022

Nitrogen is the most essential macronutrient for the growth of fruit trees and is important factor determining the fruit yield. In order to produce high-quality fruits, it is necessary to supply the appropriate nitrogen fertilizer at the right time. For this, it is a prerequisite to accurately diagnose the nitrogen status of fruit trees. The fastest and most accurate way to determine the nitrogen deficiency of fruit trees is to measure the nitrogen concentration in leaves. However, it is not easy for citrus growers to measure nitrogen concentration through leaf analysis. In this study, several machine learning models were developed to classify the nitrogen deficiency based on the concentration measurement of mineral nutrients in the leaves of tangor Shiranuhi (Citrus unshiu × C. sinensis). The data analyzed from the leaves were increased to about 1,000 training dataset through the bootstrapping method and used to train the models. As a result of testing each model, gradient boosting model showed the best classification performance with an accuracy of 0.971.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.238-245
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• 2008

This study was carried out to investigate the effect of magnesium (Mg) concentrations in nutrient solution on growth of and nutrient uptake by 'Maehyang' strawberry. Tissue analysis based on dry weight and petiole sap were also conducted to determine the threshold level in plants when Mg deficiency disorders developed in strawberry plants. In the Mg deficient plants, the spotted yellowing or yellowing area developed on the interveinal area of mature leaves. The dark brown color also developed on the interveinal area of mature leaves with marginal browning or marginal necrosis. The response in dry weight production of 'Maehyang' strawberry to elevated Mg concentrations in nutrient solution was quadratic and the equation is y=6.84+1.7533x-$0.9278x^2$ $(R^2=0.1081^{***})$. But the Mg contents in tissue increased lineally with the equation of y=0.1764+0.1275x $(R^2=0.8307^{***})$. The trends of fresh weight production and Mg concentrations in petiole sap were also quadratic (y=24.127+7.3565x-$1.125x^2$, $R^2=0.2314^{^***}$) and linear (11.954+5.793x, $R^2=0.6869^{***}$), respectively. To prevent growth suppression, the Mg concentrations based on dry weight of above ground tissue and in petiole sap should be in the range of 0.30 to 0.65% and 19 to $40mg{\cdot}kg^{-1}$, respectively, fer the commercial production of 'Maehyang' strawberry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.762-768
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• 2004

Chromium has been known to be involved in the glucose metabolism, and hence the utilization of cellular glucose is impaired in the chromium deficiency. Chromium has been recognized as an essential nutrient since the finding of low-molecular-weight Cr-binding substance (LMWCr) as a biological modifier of insulin action. Clinical chromium deficiency associated with glucose intolerance that respond to the administration of chromium. The major impediment to the use of orally administered chromium is poor absorption of trivalent chromium in its inorganic form. Trivalent chromium is more available in yeast md, more recently, as chromium picolinate for oral absorption. The widespread use of these supplements has resulted in controversy regarding chromium's role as a nutrient, its use for treatment of insulin resistance, and its potential toxicity. Most recent evidence strongly supports tile conclusion that there is little fear of toxic reactions from chromium consumption. This report reviews the evidence for the potential toxicity of chromium supplements in contrast with its usefulness as a nutrient or therapeutic agent in the treatment or prevention of insulin resistance.

• Journal of the Korean Society of Food Culture
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• v.15 no.5
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• pp.413-422
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• 2000

This study was undertaken to investigate meal pattern, nutrition knowledge and food preference of 438 rural middle school students living in ChunNam area. As far as nutrition knowledge is concerned, most subjects did not answer correctly on the items of basic five food groups, animal fat and vegetable oil, empty source of soft drink, nutrient requirement and water's role in energy metabolism. However they responded well on the item of iron deficiency and dietary source of Ca. Male students were significantly better in the answering the items of dietary source of energy and nutrient requirement than females, while female students were significantly better on the items of water's role in energy metabolism related to obesity. Generally the respondents did neither consume oil often nor consider consumption of salty food. Furthermore, only 38.6% of subjects drink milk daily in spite of understanding dietary source of Ca, which suggested that they should incorporate nutrition knowledge into dietary behavior. The preferred foods for most subjects were fruit, kimbab and ice cream. Contrastingly the food that they did not prefer was fermented vegetable probably due to strong flavor.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.558-566
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• 2018

The objective of the study was to determine nutrition regime and limitation in the Boryeng Reservoir where there's a water tunnel between Geum River and the reservoir. Evaluation was conducted through in situ algal bioassay experiments (in situ ABEs) using the cubitainer setting in the reservoirs. For in situ ABEs, we compared and analyzed variations in chlorophyll-a (CHL-a) and phosphorus concentrations in Boryeong Reservoir before and after the water tunnel construction. We then analyzed the nutrient effects on the reservoir. Analysis for nitrogen and phosphorus was done in the three locations of the reservoir and two locations of the ABEs. The in situ ABEs results showed that phosphorous and Nitrogen, the primary limiting nutrient regulating the algal biomass was not limited in the system. The treatments of phosphorus or simultaneous treatments of N+P showed greater algal growth than in the control of nitrate-treatments, indicating a phosphorus deficiency on the phytoplankton growth in the system. The water from the Geum River had 5 times higher total phosphorus (TP) than the water in the reservoir. Efficient management is required as pumping of the river water from Geum River may accelerate the eutrophication of the reservoir.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.232-237
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• 1997

Soybean plants inoculated Bradrhizobium japonicum MN 110 were grown in outdoor perlite pots with nitrogen free nutrient solution containing 1.0 mM-P(control) and 0.05 mM-P(stress) and harvested at 28, 35, 42 and 49 days after transplanting (DAT) to examine the effect of phosphorus deficiency on ureide concentration of and distribution to diffrent plant organ in nitrogen fixing soybean plant during the vegetative growth. Total dry mass of control plants increased 8.9 fold and that of phosphorus deficient plant increased 2.7 fold during the experimental period. Phosphorus deficiency reduced total phosphorus and nitrogen accumulation by 80%,40% respectively, at 28 DAT and 93%, 84%, respectively, at 49 DAT. Nitrogen concentration was reduced by phosphorus deficiency in all tissues with leaf and stem tissues affected to a greater degree than nodule and root tissues at every sampling date. Phosphorus deficiency significantly reduced soluble reduced-N and ureide-N concentration in leaf and stem but did not affect those in root. The proportion of soluble reduced-N in leaf was reduced from 60% to 50% but increased from 10% to 20% in the roots. The proportion of ureide-N in leaf of control plants was higher than that in phosphorus deficient plants, whereas, roots of phosphorus deficient plants contained a higher propotion of ureide-N than those of control plants. These indicated that phosphorus deficiency not only inhibit nitrogen fixation of nodules but also restrict the translocation of fixed nitrogen out of the root system into the xylem.(Received April 4, 1997; accepted May 2, 1997)

• Journal of Community Nutrition
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• v.4 no.1
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• pp.3-11
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• 2002

The purpose of this study is to evaluate the iron nutritional status by investigating dietary intake and analyzing the hematological iron status indices including serum transferrin receptor (sTfR) in 8 to 28 month old infants md young children taking supplementary foods. The nutrient intake of 60 healthy infants and young children from 8 to 24 months of age was investigated by means of a 24-hour recall method, and the subjects were divided into 2 groups (8- 12 months and 13-28 months) according to age. Venous blood samples from these groups were collected and measured for the following : hemoglobin(Hb), hematocrit(Hct) , mean corpuscular volume (MCV), mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration (MCHC), serum ferritin, serum iron, total iron binding capacity (TIBC), and sTfR. Anemia is defined as hemoglobin < 11g /dl , serum ferritin level < 10ng1m1 for iron deficiency , serum transferring receptor(sTfR) > 4.5mg / 1 for iron deficient erythropoiesis. Total daily calorie intake was 934.6 ${\pm}$ 284.5kcal (98.32% of RDA) on average. Average daily iron intake in infants aged 8 to 12 months was 8.92 ${\pm}$ 3.32mg. The mean daily iron intake in infants aged 13 to 28 months was 7.15 ${\pm}$ 3.35mg (90% of Recommended Dietary Allowance, RDA). Mean values for Hb, Hct sew ferritin and sTfR were 12.10 ${\pm}$ 0.77g141,36.02 ${\pm}$ 2.31%,20.91 ${\pm}$ 11.58ng/m1 and 3.78 ${\pm}$ 1.47mg /1, respectively. In the young children from 13 to 28 months of age, the prevalence of anemia was 5.6%. The prevalence of iron deficiency was 9.5% in those from 8 to 12 months of age, and 27.8% in those from 13 to 28 months of age. The prevalence of iron deficient erythropoiesis was 16.7% in infants aged 8 to 12 months and 44.4% in those aged 13 to 28 months. The prevalence of both serum ferritin level < 10ng/m1 sTfR > 4.5mg/1 was 22% in the young children aged 13 to 28 months. The measureand ment of sTfR may be a promising new tool in diagnosis of iron deficiency in early childhood when the iron deficiency is prevalent. It seems appropriate to emphasize nutritional education and evaluation to promote the iron nutritional status of infants and young children.

• Korean Journal of Community Nutrition
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• v.9 no.4
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• pp.491-500
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• 2004

To assess the quality of nutrient intake by area of Korean adults, a dietary survey with the 3-day record method was obtained from 324 subjects aged 40 years and older but younger than 70 (52.4 $\pm$ 8.7) living in a rural area (Ansung) and suburban area of a middle-sized city (Ansan). The quality of nutrient intake was assessed by analyzing Nutrient Adequacy Ratio (NAR), Mean Adequacy Ratio (MAR) and Index of Nutritional Quality (INQ). The average daily mean energy intakes were 1,832 ㎉ for Ansung and 1,842 ㎉ for Ansan, respectively. Daily intakes of fat for Ansung and Ansan subjects were 40.9 and 40.3 g, and those for protein were 75.1 and 73.1 g, respectively. The overall calorie: protein: fat ratio (CPF) of energy intake was 63 : 17 : 20. Daily mean intakes of protein, fat, calcium, phosphorus, iron, potassium, carotene, sodium, thiamin, and niacin were significantly higher in Ansung residents than in Ansan subjects (p < .05). The average intakes of energy, calcium, vitamin A were lower than Recommend Dietary Allowance (RDA) in both areas. Note, over 30% of the study subjects had less than 75% of RDA of calcium, vitamin A and riboflavin. The MAR was higher in Ansung than Ansan residents (0.86 and 0.85, respectively; p < .05). INQs were over 1 for most nutrients except calcium (0.87), and that of calcium and phosphorus was each significantly higher in Ansung than Ansan subjects. Based on these results, nutrient intake quality of subjects aged 40 to 69 years living in the surveyed rural area is comparable to that of semi-industrialized suburban area in Korea. Dietary deficiency in all of calcium, vitamin A, and riboflavin, however, was a common problem for both rural and suburban residents.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.6
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• pp.818-824
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• 2014

The nutrient composition of pasture, voluntary intake and digestibility of diet ingested by goats grazing on an introduced Leymus chinensis pasture were measured across spring (May), summer (July), autumn (October) and winter (March). In each season, 12 Inner Mongolian Cashmere goats (6 wethers and 6 does with an average live weight of $22.2{\pm}1.3$ kg and $19.5{\pm}0.8$ kg, respectively) were used to graze on a 2 hectares size paddock. Diet selection was observed and the plant parts selected by grazing goats and whole plant L. chinensis were sampled simultaneously. The alkane pair $C_{32}:C_{33}$ and $C_{36}$ were used to estimate intake and digestibility, respectively. The results showed that the plant parts selected by goats had higher crude protein (CP) and lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) than the whole plant, especially in the autumn and winter. The voluntary intake of dry matter (DM), CP, ADF, NDF, and metabolizable energy (ME) by goats was highest in summer (p<0.05). The goats ingested more CP, ME, and less ADF in spring than in autumn (p<0.05). The intakes of DM, CP, and ME were lowest in winter (p<0.05). There were significant differences in nutrient intake between wethers and does in each season, except for the ADF and ME intake per metabolic weight ($LW^{0.75}$). The nutrient digestibilities were higher in spring and summer, and decreased significantly during the autumn and winter (p<0.05). Goats, especially wethers, had a relative constant NDF digestibility across seasons, however, the apparent digestibility of CP in both wethers and does, decreased to negative values in winter. The grazing goats experienced relatively sufficient nutrients supply in spring and summer, and a severe deficiency of CP and ME in winter.

• Nutrition Research and Practice
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• v.13 no.1
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• pp.41-46
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• 2019

BACKGROUND/OBJECTIVES: Taste perception is influenced by both nutritional factors and psychological factors. This study was undertaken to measure the 4 basic taste perceptions, nutrient intake, and mental health, and to examine the factors that affect insensitive taste perception in young Japanese women. SUBJECTS/METHODS: Young women in their late teens and twenties were enrolled as subjects. Taste perception was measured by applying the filter-paper disc method over areas of the chorda tympani nerve. Nutritional status was evaluated using brief, self-administered diet history questionnaires. The index of nutritional status was based on the 2015 Japanese dietary reference intakes. Mental health was assessed using the Japanese translation of the Profile of Mood States short version. This study was approved by the ethical committee at Osaka University. RESULTS: The normal taste perception group (four basic tastes [sweet, salty, sour, and bitter] identified as normal taste perception) comprised 55.4% of the subjects, while the abnormal taste perception group (more than 1 abnormal taste perception was perceived, regardless of flavor) comprised 44.6% of the subjects. There were no significant differences in nutrient intake (except manganese) and mental health between the normal and abnormal taste perception groups. Subjects who took 5 mg to less than 7.1 mg zinc per day were at significantly decreased risk of insensitive taste perception compared to subjects who consumed less than 5 mg zinc per day [Regression coefficient 0.831, 95% confidence interval 0.694-0.996]. CONCLUSION: The present results suggest that insensitive taste perception could be associated with zinc deficiency in young women in their late teens and twenties.