• Animal Bioscience
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• v.35 no.11
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• pp.1635-1648
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• 2022

Thermal stress due to extreme changes in the thermal environment is a critical issue in cattle production. Many previous findings have shown a decrease in feed intake, milk yield, growth rate, and reproductive efficiency of cattle when subjected to thermal stress. Therefore, selecting thermo-tolerant animals is the primary goal of the efficiency of breeding programs to reduce those adverse impacts. The recent advances in molecular genetics have provided significant breeding advantages that allow the identification of molecular markers in both beef and dairy cattle breeding, including marker-assisted selection (MAS) as a tool in selecting superior thermo-tolerant animals. Single-nucleotide polymorphisms (SNPs), which can be detected by DNA sequencing, are desirable DNA markers for MAS due to their abundance in the genome's coding and non-coding regions. Many SNPs in some genes (e.g., HSP70, HSP90, HSF1, EIF2AK4, HSBP1, HSPB8, HSPB7, MYO1A, and ATP1A1) in various breeds of cattle have been analyzed to play key roles in many cellular activities during thermal stress and protecting cells against stress, making them potential candidate genes for molecular markers of thermotolerance. This review highlights the associations of SNPs within these genes with thermotolerance traits (e.g., blood biochemistry and physiological responses) and suggests their potential use as MAS in thermotolerant cattle breeding.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1526-1533
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• 2022

Small modular reactors have garnered considerable attention in the recent years. Plate fuel elements exhibit a good application prospect in small modular pressurized water reactors for marine applications. Further, improved economic benefits can be achieved by extending the core lifetime of small modular reactors. However, it is necessary to realize a large initial residual reactivity for achieving a relatively long burnup depth finally. Thus, the selection of a suitable burnable poison (BP) is a crucial factor that should be considered in the design of small modular reactors. In this study, some candidate BPs are selected to realize the effective control of reactivity. The results show that ²³¹Pa₂O₃, ²⁴⁰Pu₂O₃, ¹⁶⁷Er₂O₃, PACS-J, and PACS-L are ideal candidates of BP, and since the characteristics of BP can increase the final burnup depth of assembly, the economic benefits are gained. Additionally, an optimal combination scheme of BPs is established. Specifically, it is proved that through a reasonable combination of BPs, a low reactivity fluctuation during the lifetime can be achieved, leading to a large final burnup depth.

• Korean Journal of Poultry Science
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• v.50 no.3
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• pp.187-191
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• 2023

Korean native ducks (KNDs) continue to have a high preference from consumers due to their excellent meat quality and taste characteristics. However, due to low productivity and fixed plumage color phenotype, it could not secure a large share in the domestic market compared to imported species. In order to improve the market share of KNDs, the genetic characteristics of the breed should be identified and used for improvement and selection. Therefore, this study was conducted to identify the genetic information of colored and white KNDs using next-generation resequencing data and screening for differences between the two groups. As a result of the analysis, the genetic variants that showed significant differences between the colored and white KND groups were mainly identified as mutations related to tyrosine activity. The variants were located in the genes that affect melanin synthesis and regulation, such as EGFR, PDGFRA, and DDR2, and these were reported as the candidate genes related to plumage pigmentation in poultry. Therefore, the results of this study are expected to be useful as a basis for understanding and utilizing the genetic characteristics of KNDs for genetic improvement and selection of white broiler KNDs.

• Interdisciplinary Bio Central
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• v.4 no.1
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• pp.1.1-1.7
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• 2012

Background: The F-box proteins represent one of the largest families of proteins in eukaryotes. Apart from being a component of the ubiquitin (Ub)/26 S proteasome pathways, their regulatory roles in other cellular and developmental pathways have also been reported. One interesting feature of the genes encoding the proteins of this particular family is their variable selection patterns across different lineages. This resulted in the presence of lineage specific F-box proteins across different species. Findings: In this study, 48 non-redundant F-box proteins in E. siliculosus have been identified by a homology based approach and classified into three classes based on their variable C-terminal domains. A greater number of the F-box proteins have domains similar to the ones identified in other species. On the other hand, when the proteins having unknown or no C-terminal domain (as predicted by InterProScan) were analyzed, it was found that some of them have the polyglutamine repeats. To gain evolutionary insights on the genes encoding the F-box proteins, their selection patterns were analyzed and a strong positive selection was observed which indicated the adaptation potential of the members of this family. Moreover, four lineage specific F-box genes were found in E. siliculosus with no identified homolog in any other species. Conclusions: This study describes a genome wide in silico analysis of the F-box proteins in E. siliculosus which sheds light on their evolutionary patterns. The results presented in this study provide a strong foundation to select candidate sequences for future functional analysis.

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.23-41
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• 2017

Objectives: In this study, we seek to perform a priority selection for test substances for chronic inhalation toxicity studies, including acute and subchronic inhalation toxicity studies, which are to be performed after the construction of a chronic/carcinogenicity inhalation toxicity study facility and enactment of pertinent legislation. Methods: Through this study, qualitative and quantitative priority evaluation of test substances according to acute, subchronic and chronic categories were respectively performed and priorities were suggested by expert group review, redundancy and other methods. Meanwhile, a draft on test substance selection criteria, procedures and methods referring to the National Toxicology Program (NTP) system was proposed. Results: This study selected priorities for candidate substances for chronic inhalation toxicity studies to be conducted from 2016. Conclusions: In the future, by assessing in advance the toxicological effects of chemicals to which workers can be potentially exposed in the workplace via long-term inhalation, expected health disturbances among workers will be reduced and it is anticipated that occupational disease induced by chemicals will be effectively prevented.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.9
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• pp.1-9
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• 2011

In this paper, we propose an efficient method to create clusters of geographically distributed base stations which cooperatively transmit signals in cellular mobile communication systems. The proposed method utilizes a sequential selection approach to choose candidate base stations which can provide maximum weighted sum-rate gain when they participate in the cooperative transmission with the existing cluster. In particular, the proposed method limits the maximum number of base stations in a cluster by considering the system operational and implementation complexities. Moreover, the combinations of clusters dynamically change along with variations of channel environments. Through computer simulations, performance of the proposed method is verified by comparing with the non-cooperative transmission method and the static clustering method. Numerical result shows that the proposed sequential selection based clustering method is especially advantageous for the performance improvement of lower percentile users in terms of average throughput, and thus the proposed method can effectively improve the fairness among users.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.41-48
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• 2011

In feature selection, the selective evaluation scheme for Ant Colony Optimization(ACO) has recently been proposed, which reduces computational load by excluding unnecessary or less promising candidate solutions from the actual evaluation. Its superiority was supported by experimental results. However the experiment seems to be not statistically sufficient since it used only one dataset. The aim of this paper is to analyze convergence characteristics of the selective evaluation scheme and to make the conclusion more convincing. We chose three datasets related to handwriting, medical, and speech domains from UCI repository whose feature set size ranges from 256 to 617. For each of them, we executed 12 independent runs in order to obtain statistically stable data. Each run was given 72 hours to observe the long-time convergence. Based on analysis of experimental data, we describe a reason for the superiority and where the scheme can be applied.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3A
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• pp.217-224
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• 2010

In this paper, we propose a hard handover algorithm for a base station's self-optimization, one of the automatic operational technologies for the 3GPP LTE systems. The proposed algorithm simultaneously considers a mixed target sell selection method for optimal selection and a multiple parameter based active hysteresis method with the received signal strength from adjacent cells and the cell load information of the candidate target cells from information exchanges between eNBs through X2 interface. The active hysteresis method chooses optimal handover hysteresis value considering the costs of the various environmental parameters effect to handover performance. The algorithm works on the optimal target cell and the hysteresis value selections for a base station's automatic operational optimization of the LTE system with the gathered informaton effects to the handover performance. The simulation results show distinguished handover performances in terms of the most important performance indexes of handover, handover failure rate and load balancing.

• Molecules and Cells
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• v.39 no.12
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• pp.862-868
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• 2016

Goats (Capra hircus) are one of the oldest species of domesticated animals. Native Korean goats are a particularly interesting group, as they are indigenous to the area and were raised in the Korean peninsula almost 2,000 years ago. Although they have a small body size and produce low volumes of milk and meat, they are quite resistant to lumbar paralysis. Our study aimed to reveal the distinct genetic features and patterns of selection in native Korean goats by comparing the genomes of native Korean goat and crossbred goat populations. We sequenced the whole genome of 15 native Korean goats and 11 crossbred goats using next-generation sequencing (Illumina platform) to compare the genomes of the two populations. We found decreased nucleotide diversity in the native Korean goats compared to the crossbred goats. Genetic structural analysis demonstrated that the native Korean goat and cross-bred goat populations shared a common ancestry, but were clearly distinct. Finally, to reveal the native Korean goat's selective sweep region, selective sweep signals were identified in the native Korean goat genome using cross-population extended haplotype homozygosity (XP-EHH) and a cross-population composite likelihood ratio test (XP-CLR). As a result, we were able to identify candidate genes for recent selection, such as the CCR3 gene, which is related to lumbar paralysis resistance. Combined with future studies and recent goat genome information, this study will contribute to a thorough understanding of the native Korean goat genome.

• The Plant Pathology Journal
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• v.32 no.1
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• pp.33-46
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• 2016

In this study, the full-length nucleotide sequences of four Iranian PVY isolates belonging to $PVY^N$ strain were determined. The genome of Iranian PVY isolates were 9,703-9,707 nucleotides long encoding all potyviral cistrons including P1, HC-Pro, P3, 6K1, CI, 6K2, VPg, NIa-Pro, NIb and CP with coding regions of 825, 1,395, 1,095, 156, 1,902, 156, 564, 732, 1,557 and 801 nucleotides in length, respectively. The length of pipo, embedded in the P3 cistron, was 231 nucleotides. Phylogenetic analysis showed that the Iranian isolates clustered with European recombinant NTN isolates in the N lineage. Recombination analysis demonstrated that Iranian $PVY^N$ isolates had a typical European $PVY^{NTN}$ genome having three recombinant junctions while $PVY^N$ and $PVY^O$ were identified as the parents. We used dN/dS methods to detect candidate amino acid positions for positive selection in viral proteins. The mean ${\omega}$ ratio differed among different genes. Using model M0, ${\omega}$ values were 0.267 (P1), 0.085 (HC-Pro), 0.153 (P3), 0.050 (CI), 0.078 (VPg), 0.087 (NIa-pro), 0.079 (NIb) and 0.165 (CP). The analysis showed different sites within P1, P3 and CP were under positive selection pressure, however, the sites varied among PVY populations. To the best of our knowledge, our analysis provides the first demonstration of population structure of $PVY^N$ strain in mid-Eurasia Iran using complete genome sequences and highlights the importance of recombination and selection pressure in the evolution of PVY.