• Title/Summary/Keyword: Signaling Strength

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Differential effects of type 1 diabetes mellitus and subsequent osteoblastic β-catenin activation on trabecular and cortical bone in a mouse mode

  • Chen, Sixu;Liu, Daocheng;He, Sihao;Yang, Lei;Bao, Quanwei;Qin, Hao;Liu, Huayu;Zhao, Yufeng;Zong, Zhaowen
    • Experimental and Molecular Medicine
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    • v.50 no.12
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    • pp.3.1-3.14
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    • 2018
  • Type 1 diabetes mellitus (T1DM) is a pathological condition associated with osteopenia. $WNT/{\beta}$-catenin signaling is implicated in this process. Trabecular and cortical bone respond differently to $WNT/{\beta}$-catenin signaling in healthy mice. We investigated whether this signaling has different effects on trabecular and cortical bone in T1DM. We first established a streptozotocin-induced T1DM mouse model and then constitutively activated ${\beta}$-catenin in osteoblasts in the setting of T1DM (T1-CA). The extent of bone loss was greater in trabecular bone than that in cortical bone in T1DM mice, and this difference was consistent with the reduction in the expression of ${\beta}$-catenin signaling in the two bone compartments. Further experiments demonstrated that in T1DM mice, trabecular bone showed lower levels of insulin-like growth factor-1 receptor (IGF-1R) than the levels in cortical bone, leading to lower $WNT/{\beta}$-catenin signaling activity through the inhibition of the IGF-1R/Akt/glycogen synthase kinase $3{\beta}$ ($GSK3{\beta}$) pathway. After ${\beta}$-catenin was activated in T1-CA mice, the bone mass and bone strength increased to substantially greater extents in trabecular bone than those in cortical bone. In addition, the cortical bone of the T1-CA mice displayed an unexpected increase in bone porosity, with increased bone resorption. The downregulated expression of WNT16 might be responsible for these cortical bone changes. In conclusion, we found that although the activation of $WNT/{\beta}$-catenin signaling increased the trabecular bone mass and bone strength in T1DM mice, it also increased the cortical bone porosity, impairing the bone strength. These findings should be considered in the future treatment of T1DM-related osteopenia.

Ginsenoside Rg1 augments oxidative metabolism and anabolic response of skeletal muscle in mice

  • Jeong, Hyeon-Ju;So, Hyun-Kyung;Jo, Ayoung;Kim, Hye-Been;Lee, Sang-Jin;Bae, Gyu-Un;Kang, Jong-Sun
    • Journal of Ginseng Research
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    • v.43 no.3
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    • pp.475-481
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    • 2019
  • Background: The ginsenoside Rg1 has been shown to exert various pharmacological activities with health benefits. Previously, we have reported that Rg1 promoted myogenic differentiation and myotube growth in C2C12 myoblasts. In this study, the in vivo effect of Rg1 on fiber-type composition and oxidative metabolism in skeletal muscle was examined. Methods: To examine the effect of Rg1 on skeletal muscle, 3-month-old mice were treated with Rg1 for 5 weeks. To assess muscle strength, grip strength tests were performed, and the lower hind limb muscles were harvested, followed by various detailed analysis, such as histological staining, immunoblotting, immunostaining, and real-time quantitative reverse transcription polymerase chain reaction. In addition, to verify the in vivo data, primary myoblasts isolated from mice were treated with Rg1, and the Rg1 effect on myotube growth was examined by immunoblotting and immunostaining analysis. Results: Rg1 treatment increased the expression of myosin heavy chain isoforms characteristic for both oxidative and glycolytic muscle fibers; increased myofiber sizes were accompanied by enhanced muscle strength. Rg1 treatment also enhanced oxidative muscle metabolism with elevated oxidative phosphorylation proteins. Furthermore, Rg1-treated muscles exhibited increased levels of anabolic S6 kinase signaling. Conclusion: Rg1 improves muscle functionality via enhancing muscle gene expression and oxidative muscle metabolism in mice.

Microarray Analysis of Genes Involved with Shell Strength in Layer Shell Gland at the Early Stage of Active Calcification

  • Liu, Zhangguo;Zheng, Qi;Zhang, Xueyu;Lu, Lizhi
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.5
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    • pp.609-624
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    • 2013
  • The objective of this study was to get a comprehensive understanding of how genes in chicken shell gland modulate eggshell strength at the early stage of active calcification. Four 32-week old of purebred Xianju hens with consistent high or low shell breakage strength were grouped into two pairs. Using Affymetrix Chicken Array, a whole-transcriptome analysis was performed on hen's shell gland at 9 h post oviposition. Gene ontology enrichment analysis for differentially expressed (DE) transcripts was performed using the web-based GOEAST, and the validation of DE-transcripts was tested by qRT-PCR. 1,195 DE-transcripts, corresponding to 941 unique genes were identified in hens with strong eggshell compared to weak shell hens. According to gene ontology annotations, there are 77 DE-transcripts encoding ion transporters and secreted extracellular matrix proteins, and at least 26 DE-transcripts related to carbohydrate metabolism or post-translation glycosylation modification; furthermore, there are 88 signaling DE-transcripts. GO term enrichment analysis suggests that some DE-transcripts mediate reproductive hormones or neurotransmitters to affect eggshell quality through a complex suite of biophysical processes. These results reveal some candidate genes involved with eggshell strength at the early stage of active calcification which may facilitate our understanding of regulating mechanisms of eggshell quality.

Voluntary stand-up physical activity enhances endurance exercise capacity in rats

  • Seo, Dae Yun;Lee, Sung Ryul;Kwak, Hyo-Bum;Seo, Kyo Won;McGregor, Robin A;Yeo, Ji Young;Ko, Tae Hee;Bolorerdene, Saranhuu;Kim, Nari;Ko, Kyung Soo;Rhee, Byoung Doo;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.3
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    • pp.287-295
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    • 2016
  • Involuntary physical activity induced by the avoidance of electrical shock leads to improved endurance exercise capacity in animals. However, it remains unknown whether voluntary stand-up physical activity (SPA) without forced simulating factors improves endurance exercise capacity in animals. We examined the effects of SPA on body weight, cardiac function, and endurance exercise capacity for 12 weeks. Twelve male Sprague-Dawley rats (aged 8 weeks, n=6 per group) were randomly assigned to a control group (CON) or a voluntary SPA group. The rats were induced to perform voluntary SPA (lifting a load equal to their body weight), while the food height (18.0 cm) in cages was increased progressively by 3.5 every 4 weeks until it reached 28.5 cm for 12 weeks. The SPA group showed a lower body weight compared to the CON group, but voluntary SPA did not affect the skeletal muscle and heart weights, food intake, and echocardiography results. Although the SPA group showed higher grip strength, running time, and distance compared to the CON group, the level of irisin, corticosterone, genetic expression of mitochondrial biogenesis, and nuclei numbers were not affected. These findings show that voluntary SPA without any forced stimuli in rats can effectively reduce body weight and enhance endurance exercise capacity, suggesting that it may be an important alternative strategy to enhance endurance exercise capacity.

Performance Analysis of Handover Trigger Based on Signal Strength Measurement (신호 강도 측정 기반 핸드오버 결정 방법의 성능 분석)

  • Park, Jae-Sung;Lim, Yu-Jin
    • The KIPS Transactions:PartC
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    • v.14C no.7
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    • pp.603-610
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    • 2007
  • Effective handover decision is important for providing seamless services to mobile users. In this paper, we propose an analysis framework to evaluate the performance of handover decision based on received signal strength (RSS) measurements in terms of the late notification and false alarm probability. In our framework, we consider mobility of a mobile user, signaling delays for exchanging messages related to handover protocols, cell sizes and RSS measurement interval to stabilize RSS reading due to random measurement errors. By quantitatively scrutinizing the impact of each parameter on the late notification and false alarms, we suggest the research directions for effective handover decision mechanism that may provide fast and reliable handover.

A precast slab track partially reinforced with GFRP rebars

  • Lee, Seung-Jung;Moon, Do-Young;Ahn, Chi-Hyung;Lee, Jong-Woo;Zi, Goangseup
    • Computers and Concrete
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    • v.21 no.3
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    • pp.239-248
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    • 2018
  • This study developed and investigated a precast slab track system partially reinforced with glass fiber reinforced polymer (GFRP) rebars in the transverse direction, which mitigated the loss of track circuit current by reducing magnetic coupling between the rails and steel reinforcements. An electric analysis was conducted and the results of the analysis verified that the GFRP rebars mitigate the reduced current strength produced by electro-magnetic induction. In the study, a three-dimensional finite element method and flexural experiments were used to study the mechanical behavior of the proposed slab track.

Acute Ethanol Reduces Calcium Signaling Elicited by K+ Depolarization in Cultured Cerebellar Granule Neurons

  • Kim, Jong-Nam
    • Toxicological Research
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    • v.16 no.1
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    • pp.63-66
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    • 2000
  • The effects of acute ethanol on the high K+ induced $Ca^{2+}}$ signals were examined from primary cultures of cerebellar granule neurons. $Ca^{2+}}$ signals were measured with Calcium Green-1 based microscopic video imaging. Because $Ca^{2+}}$ signal was low in most of granule neurons without stimuli, high KCI was used for depolarization. In most case, acute exposure to ethanol reduced the peak amplitude of the $Ca^{2+}}$ signals, induced by high K+, even though low concentration of ethanol(2~10mM) was used and the effects lasted more than 30min. In was also possible to see differences of ethanol inhibition, i.e. the temporal pattern of $Ca^{2+}}$ signal reductions and the strength of inhibition of $Ca^{2+}}$ signals in cerebellar granule neurons. These results indicate that low concentration of ethanol has diverse actions on the $Ca^{2+}}$ signals in cerebellar granule neurons.

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Predicting the FTSE China A50 Index Movements Using Sample Entropy

  • AKEEL, Hatem
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.3
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    • pp.1-10
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    • 2022
  • This research proposes a novel trading method based on sample entropy for the FTSE China A50 Index. The approach is used to determine the points at which the index should be bought and sold for various holding durations. The findings are then compared to three other trading strategies: buying and holding the index for the entire time period, using the Relative Strength Index (RSI), and using the Moving Average Convergence Divergence (MACD) as buying/selling signaling tools. The unique entropy trading method, which used 90-day holding periods and was called StEn(90), produced the highest cumulative return: 25.66 percent. Regular buy and hold, RSI, and MACD were all outperformed by this strategy. In fact, when applied to the same time periods, RSI and MACD had negative returns for the FTSE China A50 Index. Regular purchase and hold yielded a 6% positive return, whereas RSI yielded a 28.56 percent negative return and MACD yielded a 33.33 percent negative return.

An Optimal AP Discovery Method in 802.11 Network (802.11망에서 최적의 AP 검색 기법)

  • Lee, Daewon
    • The Journal of Korean Association of Computer Education
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    • v.15 no.5
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    • pp.55-62
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    • 2012
  • With the development of mobile communications and Internet technology, there is a strong need to provide seamless and fast connectivity for roaming devices. Generally, the mobile host (MH) may have several available networks when entering a new wireless area. However, the standard of decision for user's internet connection is provided only the subsystem identification (SSID) and signal strength of access point (AP). These two standards could not enough to decide optimal AP to the MH. Therefore, to decide the optimal AP, more information is needed. In this paper, we present additional information such as status of MH, capacity, current load, and depth of network hierarchy, by router advertisement message at layer 3. Also, we proposed decision engine (DE) on the MH that analyzes APs and decides the optimal AP automatically by AP's status information. For the MH, wireless connection period is increased, the power consumption is decreased, and the signaling overhead is reduced. For AP and router, the load balancing is provided and the network topology can also be more efficient.

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Performance Improvement of PFMIPv6 Using Signal Strength Prediction in Mobile Internet Environment (모바일 인터넷 환경에서 신호세기 예측을 이용한 PFMIPv6의 성능 개선)

  • Lee, Jun-Hui;Kim, Hyun-Woo;Choi, Yong-Hoon;Park, Su-Won;Rhee, Seung-Hyong
    • Journal of KIISE:Information Networking
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    • v.37 no.4
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    • pp.284-293
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    • 2010
  • For the successful deployment of Mobile Internet, fast handover technologies are essential. For the past few years several handover mechanisms are suggested, and Fast Handover for Proxy Mobile IPv6 (PFMIPv6) is one of the promising schemes for this purpose. In this paper, we propose a novel L2/L3 cross layer handover scheme based on ARIMA prediction model to apply PFMIPv6 to Mobile Internet environment effectively. Performance gains are evaluated in terms of probabilities of predictive-mode operation, handover latencies, packet loss probabilities, and signaling costs. Three mobilities models are used for our simulation: Manhattan Model, Open Area Model, and Freeway Model. Simulation results show that the proposed scheme can increase probabilities of predictive-mode operation and reduce handover latency, packet loss probabilities, and signaling cost.