The Ventral Midline Thalamus Mediates Hippocampal Spatial Information Processes upon Spatial Cue Changes

Jung, Dahee,Huh, Yeowool,Cho, Jeiwon Society for Neuroscience 2019 The Journal of neuroscience Vol.39 No.12

<P>The ventral midline thalamus, consisting of the reuniens and rhomboid nuclei (RE/Rh), is a thalamic structure interconnected with the limbic systems including the hippocampus. Recently, many studies have revealed that this structure plays distinctive roles in spatial learning and memory in collaboration with hippocampal functions. However, what aspects of spatial information process are influenced by the RE/Rh is not clearly known. To elucidate the roles of RE/Rh in spatial information processing and its effects on hippocampal activity, specifically with the manipulation of spatial contents, we measured hippocampal-dependent spatial memory performance and hippocampal place cell activities after RE/Rh lesion using male C57BL/6J × 129/SvJae hybrid mice. We found that the lesion altered the behavioral aptitude in recognizing locational changes of an object. Furthermore, CA1 place cells in the lesion group showed different spatial representation patterns in recognizing the environment with cue locational changes compared with the control group. Interestingly, the patterns of CA1 place cells in recognizing the same environment previously visited were not disrupted in the lesion group compared with the control group. These findings demonstrate that the ventral midline thalamus (RE/Rh) is important in recognizing the spatial relationships, especially when spatial rearrangement of cue position was introduced.</P><P><B>SIGNIFICANCE STATEMENT</B> The ventral midline thalamic nuclei (reuniens and rhomboid) interact with the hippocampus to influence various cognitive functions requiring spatial memories, yet what aspects of spatial information process are influenced by these nuclei is not clearly known. Here, we reveal that these nuclei play a crucial role in modulating hippocampal properties only with locational rearrangement of cues, not with the familiar arrangement. These nuclei are distinctively involved in cue-dependent spatial information processes of CA1 place cells. In particular, we suggest that these nuclei modulate spatial information processing on discrete components, especially when the spatial cue relationship is modified.</P>

Greater body mass index is related to greater self-identified cold tolerance and greater insensible body mass loss

Jung, Dahee,Kim, Dami,Park, Joonhee,Lee, Joo Young BioMed Central 2016 Journal of Physiological Anthropology Vol.35 No.1

<P><B>Background</B></P><P>Insensible body mass loss (IBL) from the human body continuously occurs, which is an important component in body heat exchange. The purpose of this study was to examine the relevance of IBL to anthropometric characteristics and self-identified thermal tolerance.</P><P><B>Methods</B></P><P>A total of 289 healthy young Korean males were chosen and sorted into the following three groups: heat tolerable only (HTO, <I>N</I> = 79), cold tolerable only (CTO, <I>N</I> = 104), neither heat nor cold tolerable (NHC, <I>N</I> = 106). They weighed before and after a 30-min rest under lightly clothed condition at an air temperature of 23 ± 1 °C with a relative humidity 55 ± 5 %RH.</P><P><B>Results</B></P><P>(1) The IBL of 289 males had a mean of 90 ± 75 g h<SUP>−1</SUP> (48 ± 40 g h<SUP>−1</SUP> m<SUP>−2</SUP>); (2) No significant difference in IBL among the three groups were found; (3) Significant differences in body weight and body mass index (BMI) among three groups were found (<I>P</I> < 0.05), but insignificance was found for height (<I>P</I> = 0.726) or body surface area (<I>P</I> = 0.059); (4) CTO was approximately 4.1 kg heavier in body weight (<I>P</I> < 0.05) and higher in BMI (<I>P</I> < 0.01) than in HTO; (5) Only for the group CTO, IBL (g h<SUP>−1</SUP>) showed a positive relationship to BMI (<I>P</I> < 0.05, <I>R</I><SUP>2</SUP> = 0.056), but there was no relationship between IBL and body surface area.</P><P><B>Conclusions</B></P><P>For healthy young males within normal anthropometric ranges in Korea, IBL was positively related to BMI, and individuals with greater BMI showed greater self-identified cold tolerance, but no direct relationship was found between IBL and self-identified cold tolerance. This suggests that body physique (e.g., BMI) could be an explanatory factor between insensible body heat loss and subjective cognition on cold tolerance.</P>

Conditional Knockout of Cav2.1 Disrupts the Accuracy of Spatial Recognition of CA1 Place Cells and Spatial/Contextual Recognition Behavior

Jung, Dahee,Hwang, Yu J.,Ryu, Hoon,Kano, Masanobu,Sakimura, Kenji,Cho, Jeiwon Frontiers Media S.A. 2016 Frontiers in Behavioral Neuroscience Vol.10 No.-

<P>Hippocampal pyramidal neurons play an essential role in processing spatial information as implicated with its place-dependent firing. Although, previous slice physiology studies have reported that voltage gated calcium channels contribute to spike shapes and corresponding firing rate in the hippocampus, the roles of P/Q type calcium channels (Cav2.1) underlying neural activity in behaving mice have not been well-investigated. To determine physiological and behavioral roles of Cav2.1, we conducted place cell recordings in CA1 and hippocampus dependent learning/memory tasks using mice lacking Cav2.1 in hippocampal pyramidal neurons under CamK2α-Cre recombinase expression. Results suggested that impairments shown in behavioral tasks requiring spatial and contextual information processing were statistically significant while general neurological behaviors did not differ between groups. In particular, deficits were more profound in recognition than in acquisition. Furthermore, place cell recordings also revealed that the ability to recollect spatial representation on re-visit in the conditional knockout was also altered in terms of the cue recognition while the capability of a place cell to encode a place was intact compared to the control group. Interestingly, CA1 pyramidal neurons of conditional knockout mice showed reduced burst frequency as well as abnormal temporal patterns of burst spiking. These results provide potential evidence that Cav2.1 in hippocampal pyramidal cells modulates temporal integration of bursts, which, in turn, might influence the recognition of place field and consequently disrupt spatial recognition ability.</P>

전자섬유의 피부 밀착의복 적용을 위한 인체 부위별 피부 최대변형률

정다희(Dahee Jung),김소연(So-Yeon Kim),손아림(Arim Sohn),전보영(Bo-Young Jeon),김선영(Seon-Young Kim),이주영(Joo-Young Lee) 한국지역사회생활과학회 2017 한국지역사회생활과학회지 Vol.28 No.3

유머 요소를 적용한 휴대용 게임의 스토리텔링 양상 연구 : 닌텐도 DS Lite 타이틀을 중심으로

정다희(Dahee Jung) 한국HCI학회 2009 한국HCI학회 학술대회 Vol.2009 No.2

Titles of Nintendo DS are frequently use humor to help users fall in short time. Among many humor element, many titles use exaggeration. It is because 'exaggeration' is the best instrument to make users understand humor without complex cognitive process. Therefore, portable game using humor storytelling as a strategy for attracting various people. 본 연구는 휴대용 게임기인 닌텐도 DS Lite의 타이틀 중 유머 요소를 지닌 게임 타이틀에서 사용자들이 짧은 시간에 집중적으로 게임에 몰입할 수 있도록 돕는 역할을 하는 유머 요소가 더욱 빈번하게 발견됨을 알 수 있었다. 또한 본고에서 제시한 유머 요소 평가표를 기준으로 게임 타이틀을 분석하였을 때, 가장 많이 사용되고 있는 유머의 요소는 과장임을 알 수 있었다. 스토리를 과장하거나 캐릭터의 외모나 성격, 또는 행동을 과장함으로써 유머를 만들어내는 것은 '과장'은 복잡한 인지적 처리과정 없이도 사용자가 빠르게 유머를 이해할 수 있는 장치이기 때문이라고 여겨진다. 휴대용 게임기는 다양한 연령층과 다양한 상황에 어필하기 위한 전략으로, 언제 어디서나 간편히 몰입할 수 있는 단순한 조작과 쉬운 스토리텔링 구조를 내세우고 있다. 이러한 휴대용 게임기의 스토리텔링에 적절한 유머요소를 도입하여 사용하는 것은 사용자의 몰입을 한층 심화하는 데 도움이 되어, 퍼즐이나 스포츠, 액션 게임 등의 단순한 형식의 게임 위주의 플레이에서 벗어나 보다 다양한 게임을 즐기는 데 도움이 될 것으로 예상할 수 있다.

Fabrication and Pore Characteristics of Cu Foam by Slurry Coating Process

Park, Dahee,Jung, Eun-Mi,Yang, Sangsun,Yun, Jung-Yeul The Korean Powder Metallurgy Institute 2015 한국분말재료학회지 (KPMI) Vol.22 No.2

Metallic porous materials have many interesting combinations of physical and geometrical properties with very low specific weight or high gas permeability. In this study, highly porous Cu foam is successfully fabricated by a slurry coating process. The Cu foam is fabricated specifically by changing the coating amount and the type of polyurethane foam used as a template. The processing parameters and pore characteristics are observed to identify the key parameters of the slurry coating process and the optimized morphological properties of the Cu foam. The pore characteristics of Cu foam are investigated by scanning electron micrographs and micro-CT analyzer, and air permeability of the Cu foam is measured by capillary flow porometer. We confirmed that the characteristics of Cu foam can be easily controlled in the slurry coating process by changing the microstructure, porosity, pore size, strut thickness, and the cell size. It can be considered that the fabricated Cu foams show tremendous promise for industrial application.

머신러닝 모델을 이용한 석산 개발 발파진동 예측

정다희(Dahee Jung),최요순(Yosoon Choi) 한국암반공학회 2021 터널과지하공간 Vol.31 No.6

본 연구에서는 발파 시 사람과 주변 환경에 영향을 끼치는 발파진동(peak particle velocity, PPV)을 예측하는 모델을 개발하였다. PPV를 예측하기 위해 kNN(k-nearest neighbors), CART(classification and regression tree), SVR(support vector regression), PSO(particle swarm optimization)-SVR 알고리즘을 이용한 4가지 머신러닝 모델을 개발하고 상호 비교하였다. 머신러닝 모델을 훈련하기 위해 경상남도 창원시에 있는 욕망산을 연구지역으로 선정하고 1048개의 발파 데이터를 획득하였다. 발파데이터는 천공장, 저항선, 공간격, 최대지발장약량, 비장약량, 총공수, 에멀전비율, 이격거리, PPV로 구성되었다. 훈련된 모델들의 성능을 평가하기 위한 지표 값으로 MAE(mean absolute error), MSE(mean squared error), RMSE(root mean squared error)를 사용하였다. 평가결과 PSO-SVR 모델이 MAE, MSE, RMSE가 각각 0.0348, 0.0021, 0.0458으로 가장 우수한 예측 성능을 나타냈다. 마지막으로 개발된 머신러닝 모델을 이용하여 주변 환경에 영향을 끼치는 정도를 예측하는 방법을 제시하였다. In this study, a model was developed to predict the peak particle velocity (PPV) that affects people and the surrounding environment during blasting. Four machine learning models using the k-nearest neighbors (kNN), classification and regression tree (CART), support vector regression (SVR), and particle swarm optimization (PSO)-SVR algorithms were developed and compared with each other to predict the PPV. Mt. Yogmang located in Changwon-si, Gyeongsangnam-do was selected as a study area, and 1048 blasting data were acquired to train the machine learning models. The blasting data consisted of hole length, burden, spacing, maximum charge per delay, powder factor, number of holes, ratio of emulsion, monitoring distance and PPV. To evaluate the performance of the trained models, the mean absolute error (MAE), mean square error (MSE), and root mean square error (RMSE) were used. The PSO-SVR model showed superior performance with MAE, MSE and RMSE of 0.0348, 0.0021 and 0.0458, respectively. Finally, a method was proposed to predict the degree of influence on the surrounding environment using the developed machine learning models.

Catalytic Activity of Au/TiO₂ and Pt/TiO₂ Nanocatalysts Prepared with Arc Plasma Deposition under CO Oxidation

Chan Ho Jung,Sang Hoon Kim,Nruparaj Sahu,Dahee Park,Jung Yeul Yun,Heonphil Ha,Jeong Young Park 한국진공학회 2013 한국진공학회 학술발표회초록집 Vol.2013 No.2

Chemical characterization of the long-range transport of firework/firecracker emissions over the Korean Peninsula: A novel indicator of Asian continental outflows

Jung, Jinsang,Lee, Dahee,Jeong, Hyeonjin,Lee, Sangil,Oh, SangHyub Elsevier 2018 Atmospheric environment Vol.178 No.-

<P><B>Abstract</B></P> <P>The long-range transport (LRT) of pollutants between countries in Northeast Asia is a serious issue. However, reliable quantification of LRT pollutants has not been performed due to a lack of clear evidence of the transport between countries. Hourly chemical composition of PM<SUB>2.5</SUB> (particulate matter with a diameter of ≤2.5 μm) was measured continuously at a suburban site in Daejeon, Korea during the Lunar New Year festival period to investigate the influence of firework/firecracker emissions from China over areas downwind subject to LRT. Elevated PM<SUB>10</SUB> (particulate matter with a diameter of ≤10 μm) and PM<SUB>2.5</SUB> mass concentrations were observed over the Korean Peninsula during the third day of the Lunar New Year festival (30 January 2017) when air masses originated from the northern part of China. Water-soluble potassium (K<SUP>+</SUP>), an indicator of both firework/firecracker and biomass burning, increased significantly during the third day of the Lunar New Year festival with an episode to non-episode ratio of 7.5, whereas no increase in levoglucosan, an indicator of biomass burning, was observed. Because firework/firecracker activities do not typically occur over the Korean Peninsula during the Lunar New Year festival, elevated K<SUP>+</SUP> indicates that haze plumes mixed with firework/firecracker emissions in China impacted the Korean Peninsula through the LRT. This study finds, for the first time, clear evidence of the LRT of pollutants between source and receptor countries in Northeast Asia under Asian continental outflow.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Haze caused by firework activities in China impacted on the Korean Peninsula. </LI> <LI> Elevated K<SUP>+</SUP> over the Korean Peninsula was attributed to firework emissions from China. </LI> <LI> This study finds clear evidence of the LRT of pollutants from China to Korea. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Chemical characteristics of size-segregated atmospheric aerosols in Seoul and Daejeon, Korea during early summer and winter, respectively

Dahee Lee,Jinsang Jung,Hyeonjin Jeong,Seongho Choi,Sanghyub Oh 한국분석과학회 2017 학술대회논문집 Vol.2017 No.11