• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.607-614
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• 2016

The objectives of the study were to estimate genetic parameters for milk production traits of Holstein cattle using random regression models (RRMs), and to compare the goodness of fit of various RRMs with homogeneous and heterogeneous residual variances. A total of 126,980 test-day milk production records of the first parity Holstein cows between 2007 and 2014 from the Dairy Cattle Improvement Center of National Agricultural Cooperative Federation in South Korea were used. These records included milk yield (MILK), fat yield (FAT), protein yield (PROT), and solids-not-fat yield (SNF). The statistical models included random effects of genetic and permanent environments using Legendre polynomials (LP) of the third to fifth order (L3-L5), fixed effects of herd-test day, year-season at calving, and a fixed regression for the test-day record (third to fifth order). The residual variances in the models were either homogeneous (HOM) or heterogeneous (15 classes, HET15; 60 classes, HET60). A total of nine models (3 orders of $polynomials{\times}3$ types of residual variance) including L3-HOM, L3-HET15, L3-HET60, L4-HOM, L4-HET15, L4-HET60, L5-HOM, L5-HET15, and L5-HET60 were compared using Akaike information criteria (AIC) and/or Schwarz Bayesian information criteria (BIC) statistics to identify the model(s) of best fit for their respective traits. The lowest BIC value was observed for the models L5-HET15 (MILK; PROT; SNF) and L4-HET15 (FAT), which fit the best. In general, the BIC values of HET15 models for a particular polynomial order was lower than that of the HET60 model in most cases. This implies that the orders of LP and types of residual variances affect the goodness of models. Also, the heterogeneity of residual variances should be considered for the test-day analysis. The heritability estimates of from the best fitted models ranged from 0.08 to 0.15 for MILK, 0.06 to 0.14 for FAT, 0.08 to 0.12 for PROT, and 0.07 to 0.13 for SNF according to days in milk of first lactation. Genetic variances for studied traits tended to decrease during the earlier stages of lactation, which were followed by increases in the middle and decreases further at the end of lactation. With regards to the fitness of the models and the differential genetic parameters across the lactation stages, we could estimate genetic parameters more accurately from RRMs than from lactation models. Therefore, we suggest using RRMs in place of lactation models to make national dairy cattle genetic evaluations for milk production traits in Korea.

• Biomolecules & Therapeutics
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• 제16권4호
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• pp.312-319
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• 2008

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by hyperactivity, inattention, and impulsiveness. Current estimates suggest that 4-12% of school age children are affected by ADHD, which hampers proper social relationship and achievements in school. Even though the exact etiology of the disorder is still in the middle of active investigation, the availability of pharmacological treatments for the disorder suggest that at least the symptoms of ADHD are manageable. To develop drugs with higher efficacy and fewer side effects, it is essential to have appropriate animal models for in vivo drug screening processes. Good animal models can also provide the chances to improve our understanding of the disease processes as well as the underlying etiology of the disorder. In this review, we summarized current animal models used for ADHD research and discussed the point of concerns about using specific animal models.

• 운동영양학회지
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• 제24권2호
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• pp.22-29
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• 2020

[Purpose] Exercise is thought to have a significant effect on chemotherapy, and previous studies have reported that exercise can increase patient survival. Thus, in this review, we aimed to summarize various animal models to analyze the effects of exercise on breast cancer. [Methods] We summarized types of breast cancer animal models from various reports and analyzed the effects of exercise on anti-cancer factors in breast cancer animal models. [Results] This review aimed to systematically investigate if exercise could aid in suppressing breast cancer. Our study includes (a) increase in survival rate through exercise; (b) the intensity of exercise should be consistent and increased; (c) a mechanism for inhibiting carcinogenesis through exercise; (d) effects of exercise on anti-cancer function. [Conclusion] This review suggested the necessity of a variety of animal models for preclinical studies prior to breast cancer clinical trials. It also provides evidence to support the view that exercise plays an important role in the prevention or treatment of breast cancer by influencing anticancer factors.

• 한국축산식품학회지
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• 제42권6호
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• pp.981-995
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• 2022

Cognitive dysfunction is a common symptom of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, and is known to be caused by the structural and functional loss of neurons. Many natural agents that can improve cognitive function have been developed and assessed for efficacy using various cognitive deficit animal models. As the gut environment is known to be closely connected to brain function, probiotics are attracting attention as an effective treatment target that can prevent and mitigate cognitive deficits as a result of neurodegenerative diseases. Thus, the objective of this review is to provide useful information about the types and characteristics of cognitive deficit animal models, which can be used to evaluate the anti-cognitive effects of probiotics. In addition, this work reviewed recent studies describing the effects and treatment conditions of probiotics on cognitive deficit animal models. Collectively, this review shows the potential of probiotics as edible natural agents that can mitigate cognitive impairment. It also provides useful information for the design of probiotic treatments for cognitive deficit patients in future clinical studies.

• 정신신체의학
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• 제2권1호
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• pp.46-51
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• 1994

Model' is one of the well-used, but poorly understood word in the neurobehavioral research. After Darwin's evolutionary theory, it has been generally believed that human is different from animals in terms of the complexity, not of the essential. This notion could be applied to the mind as well as body. Therefore, it became possible to establish animal models in the scientific field of mind. Experimental analysis of the animal behavior becomes an important area for establishing an animal model of human psychopathology because behavior is the ambassador of the mind. A model emphasizes a structural correspondence between sets of causally related variables in two different domains such as the animal and the human. The first selection of elements of the two domains in correspondence called the initial analogy. Once the initial analogy is formed. causally related variables in the two domains are examined and arrayed The structural parallel is the formal analogy of a model, and similarities between corresponding variables are called material analogy. Models may serve any of three major functions ; heuristic, evidential and representative. In many cases, utilizing models may be more practical than directly assessing the domain of primary interest, since technical and/or ethical problems are more serious in the human domain. Although modeling is important to study human psychopathology, rare animal models approved to be a good model for the human psychopathology up to now. Developing the appropriate model is urgent to solve many problems raised from human psychopathology.

• Archives of Plastic Surgery
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• 제44권5호
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• pp.361-369
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• 2017

As the popularity of fat grafting research increases, animal models are being used as the source of pre-clinical experimental information for discovery and to enhance techniques. To date, animal models used in this research have not been compared to provide a standardized model. We analyzed publications from 1968-2015 to compare published accounts of animal models in fat grafting research. Data collected included: species used, graft characteristics (donor tissue, recipient area, amount injected, injection technique), time of sacrifice and quantification methods. Mice were most commonly used (56% of studies), with the "athymic nude" strain utilized most frequently (44%). Autologous fat was the most common source of grafted tissue (52%). Subcutaneous dorsum was the most common recipient site (51%). On average, $0.80{\pm}0.60mL$ of fat was grafted. A single bolus technique was used in 57% of studies. Fat volume assessment was typically completed at the end of the study, occurring at less than 1 week to one year. Graft volume was quantified by weight (63%), usually in conjunction with another analysis. The results demonstrate the current heterogeneity of animal models in this research. We propose that the research community reach a consensus to allow better comparison of techniques and results. One example is the model used in our laboratory and others; this model is described in detail. Eventually, larger animal models may better translate to the human condition but, given increased financial costs and animal facility capability, should be explored when data obtained from small animal studies is exhausted or inconclusive.

• Animal Bioscience
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• 제37권4호
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• pp.622-630
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• 2024

Objective: Pig breeders cannot obtain phenotypic information at the time of selection for sow lifetime productivity (SLP). They would benefit from obtaining genetic information of candidate sows. Genomic data interpreted using deep learning (DL) techniques could contribute to the genetic improvement of SLP to maximize farm profitability because DL models capture nonlinear genetic effects such as dominance and epistasis more efficiently than conventional genomic prediction methods based on linear models. This study aimed to investigate the usefulness of DL for the genomic prediction of two SLP-related traits; lifetime number of litters (LNL) and lifetime pig production (LPP). Methods: Two bivariate DL models, convolutional neural network (CNN) and local convolutional neural network (LCNN), were compared with conventional bivariate linear models (i.e., genomic best linear unbiased prediction, Bayesian ridge regression, Bayes A, and Bayes B). Phenotype and pedigree data were collected from 40,011 sows that had husbandry records. Among these, 3,652 pigs were genotyped using the PorcineSNP60K BeadChip. Results: The best predictive correlation for LNL was obtained with CNN (0.28), followed by LCNN (0.26) and conventional linear models (approximately 0.21). For LPP, the best predictive correlation was also obtained with CNN (0.29), followed by LCNN (0.27) and conventional linear models (approximately 0.25). A similar trend was observed with the mean squared error of prediction for the SLP traits. Conclusion: This study provides an example of a CNN that can outperform against the linear model-based genomic prediction approaches when the nonlinear interaction components are important because LNL and LPP exhibited strong epistatic interaction components. Additionally, our results suggest that applying bivariate DL models could also contribute to the prediction accuracy by utilizing the genetic correlation between LNL and LPP.

• 한국초지조사료학회지
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• 제40권3호
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• pp.167-176
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• 2020

The objective of the present study was to determine the best model to describe and quantify the changes in live body weight, height at withers, height at rump, body length and chest girth of Holstein cows raised under Korean feeding conditions for 50 months. The five standard growth models namely polynomial linear regression models, regression of growth variables on the first and second-order of ages in days (model 1) and regression of growth variables on age covariates from first to the third-order (model 2) as well as non-linear models were fitted and evaluated for representing growth pattern of Holstein cows raised in Korean feeding circumstances. Nonlinear models fitted were three exponential growth curve models; Brody, Gompertz, and von Bertalanffy functional models. For this purpose, a total of 22 Holstein cows raised in Korea used in the period from April 2016 to May 2020. Each model fitted to monthly growth curve records of dairy cows by using PROC NLIN procedure in SAS program. On the basis of the results, nonlinear models showed the lower root mean square of error (RMSE) for live body weight, height at withers, height at rump, body length and chest girth (12.22, 1.95, 1.55, 4.04, 2.06) with higher correlation coefficiency (R²) values for live body weight, height at withers, height at rump, body length and chest girth (0.99, 0.99, 0.99, 1.00, 1.00). Overall, the evaluation of the different growth models indicated that the Gompertz model used in the study seemed to be the most appropriate one for standard growth of Holstein cows raised under Korean feeding system.

• 재활치료과학
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• 제1권1호
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• pp.39-56
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• 2012

서론 : 동물 연구는 작업치료에 직접적으로 적용할 수 없으나, 인간을 대상으로 한 연구와 함께 작업치료의 이론과 임상에 필수적인 지식을 제공한다. 본 논문의 목적은 신경과학적 관점에서 동물모델이 작업치료의 이론과 임상에 어떠한 가능성을 가져다 줄 수 있는지를 살펴보는 것이다. 본론 : 동물 모델을 통해 얻은 지식은 뇌신경 질환의 기전과 관련된 신경 회로에 대한 이해를 돕는다. 이러한 지식을 바탕으로, 연구자들은 뇌신경 질환에 대한 여러 가지 가정들을 동물 모델을 통해 확인해 볼 수 있다. 또한, 여러 동물 실험들을 통해 쌓인 지식들은 인간에게 적용할 수 있는 새로운 치료적 접근들을 제시해 줄 수 있으며 치료에 대한 효율성을 높여줄 수 있다. 결론 : 동물 모델을 통해 얻은 지식은 뇌신경 질환의 기전과 관련된 신경 회로에 대한 이해를 돕는다. 이러한 지식을 바탕으로, 연구자들은 뇌신경 질환에 대한 여러 가지 가정들을 동물 모델을 통해 확인해 볼 수 있다. 또한, 여러 동물 실험들을 통해 쌓인 지식들은 인간에게 적용할 수 있는 새로운 치료적 접근들을 제시해 줄 수 있으며 치료에 대한 효율성을 높여줄 수 있다.

• Biomolecules & Therapeutics
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• 제15권1호
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• pp.7-15
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• 2007

There have been various animal models of skin inflammation. These models have been used for establishing anti-inflammatory activity of the topical agents including cosmetics. Here, the molecular mechanisms of most widely-used animal models of skin inflammation including contact irritation, acute and chronic inflammation, and delayed-type hypersensitivity are summarized. Against these animal models, varieties of plant flavonoids showed anti-inflammatory activity. The action mechanisms of anti-inflammation by topical flavonoids are presented. A therapeutic potential of flavonoids is discussed.