• Title/Summary/Keyword: negative feedback

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Effects of Priming Progesterone on the LH Surge Expressions in Ovariectomized Shiba Goats (LH surge 발현에 대한 서로 다른 Progesterone 농도의 효과)

  • Kim, Seung-Joon
    • Journal of Veterinary Clinics
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    • v.31 no.1
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    • pp.25-30
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    • 2014
  • This study tested the hypothesis that the priming effects of progesterone on the timing of the LH surge induced by exogenous estradiol are more potentiated the negative feedback actions of progesterone on LH secretion by the existence of estradiol. In previous studies, the time interval from estradiol infusion until the peak of LH surge was gradually and significantly extended by the different levels of progesterone treated before estradiol infusions. Longterm ovariectomized Shiba goats that had received implants of estradiol capsules (Day 0) and three different progesterone silastic packet inducing follicular, subluteal and luteal levels of progesterone were divided into three groups such as non-P, low-P and high-P group. Blood samples were collected daily throughout the experiment for the analysis of gonadal steroid hormone levels. On Day 7, all devices of progesterone and estradiol packets were removed but estradiol capsules were maintained during the experiment, and blood samples were collected at 1 hr interval for 12 h from the time of progesterone removals to determine peripheral changes of estradiol and progesterone concentration. Then all animals were infused estradiol on the Day 7 after 13 h from the removals of progesterone devices with a peristaltic pump into jugular vein at a rate of 3-6 ${\mu}g/h$ for 36 h. For analysis of peripheral LH and estradiol concentration, blood samples were collected via another jugular vein at 2 h intervals for 52 h (from 4 h before the start of estradiol infusion to 48 h after the start of estradiol infusion). In all animals of the three groups treated with estradiol infusion, an LH surge was expressed but the peak time of LH surge was different. This time interval was not extended by the different levels of progesterone treated before estradiol infusions and the difference was not significant during this interval between the Low P and the High P groups. Progesterone pretreatment may contribute to regulating the neural system that is responded by estradiol, and estradiol existence potentiates the negative feedback effect of progesterone on GnRH/LH surge-generating system.

A Study on the Efficient Human-Robot Interaction Style for a Map Building Process of a Home-service Robot (홈서비스로봇의 맵빌딩을 위한 효율적인 휴먼-로봇 상호작용방식에 대한 연구)

  • Lee, Woo-Hun;Kim, Yeon-Ji;Kim, Hyun-Jin;Yang, Gyun-Hye;Park, Yong-Kuk;Bang, Seok-Won
    • Archives of design research
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    • v.18 no.2 s.60
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    • pp.155-164
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    • 2005
  • Home-service robots need to have sufficient spatial information about the surroundings for interacting with human intelligently and performing services efficiently. It is very important to investigate the efficient interaction style that supports map building task through human-robot collaboration. We first analyzed map building task with a cleaning robot and drew 4 design factors and tentative solutions, including map building procedure (task-preferred procedure/space- preferred procedure), LCD display installation (robot/robot+remote control), navigation method (push type/pull type), feedback modality(GUI/GUI+TTS). The design factors and tentative solutions were defined as independent variables and levels. This research investigated how those variables affect to the human task performance and behavior in map building tast. 8 kinds of experiment prototypes were built and usability test among 16 house wives was conducted for acquiring empirical data. As the experiment result, in terms of map building procedure, space-preferred procedure indicated better task performance than task-proffered procedure as we expected. For the LCD display installation factor, remote control with LCD display indicated higher task performance and subjective satisfaction. In robot navigation method, it was very difficult to find a significant difference between push type and pull type which contrary to our expectation. In fact, push type indicated higher subjective satisfaction. Also in feedback modality, we have acquired negative feedback an additional TTS operation guidance. It seems that robot's autonomy before achieving spatial information is rudiment condition which means users are just interacting with a mobile appliance. Thus they prefer remote-control-based interaction style in robot map building process as they used in traditional appliance control.

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Studies on Genetics and Breeding of Rainbow Trout(Oncorhynchus mykiss) II. Relationships between Levels of Serum LH, FSH and Estradiol-$17{\beta}$ ; and Levels of Albumin, Total Protein, and Triglycerides ; and their Effect on the Changes of Gonadosomatic Indices in the Ovarian Development in the Rainbow Trout (무지개송어의 유전 육종학적 연구 II. 무지개송어의 난소 발달에 영향을 미치는 혈청중 LH, FSH, Estradiol-$17{\beta}$ 수준과 Albumin, Total Protein, Triglycerides 함량과의 관계 및 성선지수 변화간의 상관관계)

  • Yoon Jong-Man;KIM Gye-Yoong;PARK Hong-Yang
    • Journal of Aquaculture
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    • v.4 no.2
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    • pp.97-110
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    • 1991
  • This study was undertaken to understand the seasonal changes of hormone levels such as luteinizing hormone (LH), follicle stimulating hormone (FSH) and estradiol-$17{\beta}$, serum components such as albumin, total protein and triglycerides, and GSI of rainbow trout (Onco-rhynchus mykiss) under the normal-light circumstances. LH levels were the highest in November whereas FSH levels were decreased progressively from October to February. Serum GTH, such as LH and FSH, levels were low immediately after egg-stripping and were significantly increased in the summer in association with the initiation of vitellogenesis. Serum albumin, total protein, and triglycerides were significantly increased in August in association with initiation of vitellogenesis and were peak in November prior to egg-stripping. Oocyte growth, measured by oocyte diameter and GSI, was significantly increased in August and showed the highest value in January. Correlation coefficients of serum LH with FSH and estradiol-$17{\beta}$ were +0.844 and +0.947, respectively. Correlation coefficients of estradiol-$17{\beta}$ with albumin and total protein were +0.634 and +0.859, respectively. Correlation coefficients of serum estradiol-$17{\beta}$ with triglycerides and GSI were +0.673 and +0.694, respectively. Probably by positive feedback mechanism, LH, FSH and estradiol-$17{\beta}$ appeared to stimulate to liver to secrete albumin, total protein and triglycerides for vitellosenesis.

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Radiation Effect on NO, NOS and TGF-$\beta$ Expressions In Rat Lung (쥐의 폐에서 방사선이 Nitric Oxide (NO), Nitric Oxide Synthase (NO) 및 TGF- $\beta$의 발현에 미치는 영향)

  • Oh Young-Taek;Park Kwang-Joo;Kil Hoon-Jong;Ha Mahn Joon;Chun Mison;Kang Seung-Hee;Park Seong-Eun;Chang Sei-Kyung
    • Radiation Oncology Journal
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    • v.18 no.4
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    • pp.321-328
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    • 2000
  • Purpose :NOS2 induce NO Production and NO activate TGF-${\beta}$. The TGF-${\beta}$ is a inhibitor of NOS2. If this negative feedback mechanism operating in radiation pneumonitis model, NOS2 inhibitor may play a role in TGF-${\beta}$ suppression. We planned this study to evaluate the expression patterns of NO, NOS2 and TGF-${\beta}$ in vivo radiation pneumonitis model. Materials and Methods : Sixty sprague-Dawley rat were irradiated 5 Gy or 20 Gy. They were sacrificed 3, 7, 14, 28 and 56 days after irradiation. During sacrifice, we peformed broncho-alveolar lavage (BAL). The BAL fluids were centrifuged and supernatents were used for measure NO and TGF-${\beta}$, and the cells were used for RT-PCR. Results : After 5 Gy of radiation, NO in BAL fluid increased at 28 days in both lung and TGF-${\beta}$ in left lung at 56 days. NO increased in BAL fluid at 28 days in both lung after irradiation and TGF-${\beta}$ in right lung at 28-56 days after 20 Gy of radiation. After 5 Gy of radiation, NOS2 expression was increased in right lung at 14 days, in both lung at 28 days and in left lung at 56 days. TGF-${\beta}$ expression was reduced in both lung at 28 days and increased in left lung at 56 days. Conclusions :The Proposed feedback mechanism of NO, NOS2 and TGF-${\beta}$ was operated in vivo radiation pneumonitis model. At 56 days, however, NOS2 and TGF-${\beta}$ expressed concurrently in left lung after 5 Gy and in both lung after 20 Gy of radiation.

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Application and Effectiveness of a Preceptorship for the Improvement of Clinical Education (임상실습 교육개선을 위한 일 실습지도자 활용모델 (preceptorship model)의 적용 및 효과에 관한 연구 -암센타, 재활센타, 중환자실 실습을 중심으로-)

  • 이원희;김소선;한신희;이소연;김기연
    • Journal of Korean Academy of Nursing
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    • v.25 no.3
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    • pp.581-596
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    • 1995
  • Clinical practice in nursing education provides an opportunity for students, through the process of ap-plying theoretical knowledge to practice, and to learn nursing skills as well as being socialized into nursing and as such decrease the reality shock of actual nursing practice. Because of a shortage of nursing faculty, the job of achieving the objectives of the clinical practice had been turned over to the head nurses. This resulted in many problems, such as, unclear location of responsibilities and inadequate feedback from head nurses. Therefore this study was done to introduce and evaluate the use of preceptors as a way to minimize the above problems, and to maximize the achievement of the clinical practice objectives. Using an adaptation of Zerbe's (1991) three-tiered team model, clinical practice was done using a preceptor, a head nurse and a clinical instructor, each with different and well defined roles. The subjects of this study were 67 senior students of the College of Nursing of Y University in Seoul whose clinical practice in adult nursing was carried out between May 1, 1994 and December 8, 1994. There were 22 preceptors who had at least two years of clinical experience and who were recommended by their head nurses. They were given additional education on the philosophy and objectives of the College of Nursing, on communication skills, on the theory and practice of education, and on nursing diagnosis and education evaluation. The role of the preceptor was to work one-to-one with students in their practice. The role of the head nurse was to supervise and evaluate the preceptors. The role of the clinical instructor was to provide the education program for the preceptors, to provide ad-vice and suggestions to the preceptors and to maintain lines of communication with the college. With each of these roles in place, it was thought that the effectiveness and efficiency of the clinical practice could be increased significantly. To evaluate the effectiveness of the preceptorship, the three - tiered model, Lowery's Teacher Evaluation Opinion Form translated and adapted to Korea was used to measure student statisfaction. The Clinical Practice Compentency Evaluation Tool developed by Lee et ai was also used to measure student competencies. The results of this study are as follows 1. The satisfaction with clinical practice was higher with the introduction of the perceptors than it was before they were used. (t=-5.96, p=<.005) 2. The clinical practice competencies were higher with the introduction of the preceptors than it was before they were used(t=-5.l3, p<.005) 3. In order to analyze areas not measured by the quantitative tools additional analysis of the open questions was done. The results of this analysis showed that : 1) The students felt positive about their sense of security, confidence, handling of responsbility, and being systematic. They also felt positive about improvements in knowledge, opportunities for direct care, and socialization. 2) The students felt negative about the technical part of their role, lack of knowledge by the preceptor, unprofessional attitudes on the part of the preceptor, difficulty in the role of the professional nurse(student). 3) The preceptors felt positive about their responsibility, motivation, and relationship with the college. 4) The preceptors felt negative about their bur-den. Introduction of the preceptorship model will lead to change and improvement in the negative factors discussed above, solve problems in the present clinical education system, increase continuity in the education of the students, help with socialization of the students and motivation of the preceptors to up-grade their education and increase their confidence. These objectives must be obtained to further the development of professional nursing, and thus, making the preceptorship a reality is our job for the future.

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The Infuence of Venture Club Activity by University Student's Goal-Oriented Behavior Model on Self-determination and Startup Intention: Focused on the Medaiation Effects of Big 5 (벤처동아리활동 대학생의 목표 지향적 행동모델이 자기결정성 및 창업의지에 미치는 영향: 성격 5요인의 매개효과)

  • Park, Hwa Soon;Byun, Sang Hea
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.2
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    • pp.79-93
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    • 2021
  • The question of why do you want to start a "start?" Is the most basic step in trying to do something. In other words, previous studies have shown that the degree of confidence in an individual's decision affects the setting of a specific purpose. Based on this, this study aims to provide basic data for deriving the direction of entrepreneurship education in college students by analyzing the effects of goal-oriented behavioral model on college students' self-determination and intention to start a business through the 5 factor model. To achieve the purpose of the study, a self-report questionnaire was conducted from October 01 to November 11, 2019 for university students attending located in Gyeonggi-do, Seoul. A total of 150 questionnaires were distributed, and 125 parts were used for the final analysis, except 25 parts with insincere responses or errors. Data were analyzed using SPSS Win 24, and reliability, validity analysis, frequency analysis, One-way ANOVA and regression analysis were performed, and three-step regression analysis and Sobel verification were performed for mediating effects. The summary of the study is as follows. First, the influence of university students' goal-oriented behavioral model on self-determination showed that attitudes, subjective norms, and perceived behavioral controls had statistically significant positive effects, and positive and negative expectations were statistically significant. Did not affect. Therefore, the higher the attitude, subjective norms, and perceived behavioral control, the higher the university students' self-determination. Second, the influence of college students' goal-oriented behavioral model on the intention to start a business was as follows.). As a result, the higher the perceived behavioral control and positive expectation, the higher the intention to start up. Third, regression model 1 showed that the behavioral control and positive expectation sentiment among the goal-oriented behavioral model had a significant positive influence on the college students' intention to start a business. Affected. Regression model II added the parameters of the 5 factor model, which increased 2.5% of explanatory power than the first regression model. Perceived behavioral control and positive expectations had a statistically significant positive effect, negative expectations had a statistically significant negative effect, and among the 5 factor model, openness had a statistically significant positive (+) Affected. From these results, it can be seen that the Big Five personality factors have a mediating effect on the relationship between goal-oriented behavior model and intention to start up. This study confirmed that the goal-oriented behavioral model of college students is an important variable in implementing self-determination and intention to start a business. In addition, by using his Big 5 personality factors as positive feedback, he has proved to play an important role by identifying the mediation role that can be set, planned and utilized to plan and achieve his life. The result of this study is that college students are interested in the intention of individual start-ups, so they are not freed from difficult employment difficulties. It is intended to provide basic data useful in the age of creation of government.

Impact of Semantic Characteristics on Perceived Helpfulness of Online Reviews (온라인 상품평의 내용적 특성이 소비자의 인지된 유용성에 미치는 영향)

  • Park, Yoon-Joo;Kim, Kyoung-jae
    • Journal of Intelligence and Information Systems
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    • v.23 no.3
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    • pp.29-44
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    • 2017
  • In Internet commerce, consumers are heavily influenced by product reviews written by other users who have already purchased the product. However, as the product reviews accumulate, it takes a lot of time and effort for consumers to individually check the massive number of product reviews. Moreover, product reviews that are written carelessly actually inconvenience consumers. Thus many online vendors provide mechanisms to identify reviews that customers perceive as most helpful (Cao et al. 2011; Mudambi and Schuff 2010). For example, some online retailers, such as Amazon.com and TripAdvisor, allow users to rate the helpfulness of each review, and use this feedback information to rank and re-order them. However, many reviews have only a few feedbacks or no feedback at all, thus making it hard to identify their helpfulness. Also, it takes time to accumulate feedbacks, thus the newly authored reviews do not have enough ones. For example, only 20% of the reviews in Amazon Review Dataset (Mcauley and Leskovec, 2013) have more than 5 reviews (Yan et al, 2014). The purpose of this study is to analyze the factors affecting the usefulness of online product reviews and to derive a forecasting model that selectively provides product reviews that can be helpful to consumers. In order to do this, we extracted the various linguistic, psychological, and perceptual elements included in product reviews by using text-mining techniques and identifying the determinants among these elements that affect the usability of product reviews. In particular, considering that the characteristics of the product reviews and determinants of usability for apparel products (which are experiential products) and electronic products (which are search goods) can differ, the characteristics of the product reviews were compared within each product group and the determinants were established for each. This study used 7,498 apparel product reviews and 106,962 electronic product reviews from Amazon.com. In order to understand a review text, we first extract linguistic and psychological characteristics from review texts such as a word count, the level of emotional tone and analytical thinking embedded in review text using widely adopted text analysis software LIWC (Linguistic Inquiry and Word Count). After then, we explore the descriptive statistics of review text for each category and statistically compare their differences using t-test. Lastly, we regression analysis using the data mining software RapidMiner to find out determinant factors. As a result of comparing and analyzing product review characteristics of electronic products and apparel products, it was found that reviewers used more words as well as longer sentences when writing product reviews for electronic products. As for the content characteristics of the product reviews, it was found that these reviews included many analytic words, carried more clout, and related to the cognitive processes (CogProc) more so than the apparel product reviews, in addition to including many words expressing negative emotions (NegEmo). On the other hand, the apparel product reviews included more personal, authentic, positive emotions (PosEmo) and perceptual processes (Percept) compared to the electronic product reviews. Next, we analyzed the determinants toward the usefulness of the product reviews between the two product groups. As a result, it was found that product reviews with high product ratings from reviewers in both product groups that were perceived as being useful contained a larger number of total words, many expressions involving perceptual processes, and fewer negative emotions. In addition, apparel product reviews with a large number of comparative expressions, a low expertise index, and concise content with fewer words in each sentence were perceived to be useful. In the case of electronic product reviews, those that were analytical with a high expertise index, along with containing many authentic expressions, cognitive processes, and positive emotions (PosEmo) were perceived to be useful. These findings are expected to help consumers effectively identify useful product reviews in the future.

Site Selection Model for Wetland Restoration and Creation for the Circulation of Water in a Newly-built Community (신도시 물순환체계 구축을 위한 습지조성 입지선정에 관한 연구)

  • Choi, Hee-Sun;Kim, Kwi-Gon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.36 no.6
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    • pp.43-54
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    • 2009
  • This study attempted to develop a model for selecting sites for ecologically effective, multi-functional wetlands during the environmental and ecological planning stage, prior to land use Planning. This model was developed with an emphasis upon the creation of a water circulation system for a newly-created city, dispersing and retaining the run-off that is increased due to urbanization and securing spaces to create wetlands that can promote urban biodiversity. A series of Precesses for selecting sites for wetland restoration and creation - watershed analysis, selection of evaluation items, calculation of weights, reparation of thematic maps and synthesis - were incorporated into the model. Its potentials and limitations were examined by applying it to the recently-planned WiRae New Community Development Area, which is located in the Seoul metropolitan region. At the watershed analysis stage, the site was divided into 13 sub-catchment areas. Inflow to watersheds including the area was $3,020,765m^3$ Run-off before and after development is estimated as $1,901,969m^3$ and $1,970,735{\sim}2,039,502m^3$, respectively. The total storage capacity required in the development area amounts to $68,766{\sim}137,533m^3$. When thematic maps were overlapped during the selection stage for wetland sites, 13 sub-catchment areas were prioritized for wetland restoration and creation. The locations and areas for retaining run-off showed that various types of wetlands, including retaining wetlands (area wetlands), riverine wetlands (linear wetlands) and pond wetlands (point wetlands), can be created and that they can be systematically connected. By providing a basic framework for the water circulation system plan of an entire city, it may be used effectively in the space planning stage, such as planning an urban eco-network through integration with greet areas. In order to estimate reasonable run-off and create an adequate water circulation system however, a feedback process following land use planning is required. This study strived to promote urban changes in a positive direction while minimizing urban changes in negative forms.

Exploration of Children's Age and Parental Emotional Supportiveness that Impact the Accuracy of Children's Memory (아동의 회상 보고 정확성에 아동의 연령, 양육자의 지지가 미치는 영향)

  • Lee, Seungjin
    • Korean Journal of Culture and Social Issue
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    • v.22 no.4
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    • pp.523-541
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    • 2016
  • Both the child's and defendant's testimonies play crucial roles in the court's ruling of a child abuse case. Thus, empirical studies examining a child's truthful report, that is, disclosure, of his or her experience and recantation of the disclosure have manifold practical implications. The objective of the present study was to examine how easily a child recants his or her testimony after witnessing and disclosing an adult engaging in a small mistake. Furthermore, this study examined whether the child's age and emotional support from his or her caregiver predict the recantation of the child's testimony. Children of age 5-8 years played with dolls with the experimenter and witnessed the experimenter breaking the doll mask. The experimenter asked the children to keep it a secret. Then the children had the first memory interview, during which the interviewer induced the child to disclose the incident. Based on the treatment conditions, some children were provided supportive feedback while other received unsupportive feedback from their primary caregivers (mother) regarding the disclosure, then were interviewed for the second time. First, the author of this study examined whether the children would recant their disclosure (whether they would deny the incident after telling the truth of about what happened to the doll), and also examined the features of the child's voluntary reports, that is, the degree of their honesty. The findings of the experiment indicated that there were age-specific differences in the frequency of recantation, meaning that older children (8-9-year-olds) showed a stronger tendency to maintain their recantation in the second interview than relatively younger children (6-7-year-olds). Furthermore, children who received supportive responses from their mothers regarding the disclosure demonstrated more honest reports compared to those who received unsupportive responses from their mothers. The findings of this study assist the understanding of the effects of social-motivational factors on the process of children disclosing the truth when voluntarily recalling a negative incident that they had experienced and provide practical implications in legal aspects.

Metabolic Characteristic of the Liver of Dairy Cows during Ketosis Based on Comparative Proteomics

  • Xu, Chuang;Wang, Zhe;Liu, Guowen;Li, Xiaobing;Xie, Guanghong;Xia, Cheng;Zhang, Hong You
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.7
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    • pp.1003-1010
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    • 2008
  • The objective of the present study was to identify differences in the expression levels of liver proteins between healthy and ketotic cows, establish a liver metabolic interrelationship of ketosis and elucidate the metabolic characteristics of the liver during ketosis. Liver samples from 8 healthy multiparous Hostein cows and 8 ketotic cows were pooled by health status and the proteins were separated by two-dimensional-electrophoresis (2D-E). Statistical analysis of gels was performed using PDQuest software 8.0. The differences in the expression levels of liver proteins (p<0.05) between ketotic and healthy cows were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-TOF) tandem mass spectrometry. Five enzymes/proteins were identified as being differentially expressed in the livers of ketotic cows: expression of 3-hydroxyacyl-CoA dehydrogenase type-2 (HCDH), acetyl-coenzyme A acetyltransferase 2 (ACAT) and elongation factor Tu (EF-Tu) were down-regulated, whereas that of alpha-enolase and creatine kinase were up-regulated. On the basis of this evidence, it could be presumed that the decreased expression of HCDH, which is caused by high concentrations of acetyl-CoA in hepatic cells, in the livers of ketotic cows, implies reduced fatty acid ??oxidation. The resultant high concentrations of acetyl-CoA and acetoacetyl CoA would depress the level of ACAT and generate more ??hydroxybutyric acid; high concentrations of acetyl-CoA would also accelerate the Krebs Cycle and produce more ATP, which is stored as phosphocreatine, as a consequence of increased expression of creatine kinase. The low expression level of elongation factor Tu in the livers of ketotic cows indicates decreased levels of protein synthesis due to the limited availability of amino acids, because the most glucogenic amino acids sustain the glyconeogenesis pathway; thus increasing the level of alpha-enolase. Decreased protein synthesis also promotes the conversion of amino acids to oxaloacetate, which drives the Krebs Cycle under conditions of high levels of acetyl-CoA. It is concluded that the livers of ketotic cows possess high concentrations of acetyl-CoA, which through negative feedback inhibited fatty acid oxidation; show decreased fatty acid oxidation, ketogenesis and protein synthesis; and increased gluconeogenesis and energy production.