• Title/Summary/Keyword: Sensing mechanism

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Location Recognition Mechanism of Mobile Node for Fast Handover on Proxy Mobile IPv6 (프록시 모바일 IPv6에서 빠른 핸드오버를 위한 이동단말의 위치인지 메커니즘)

  • Bae, Sang-Wook;Kim, Hee-Min;Oudom, Keo;Han, Sun-Young
    • Journal of KIISE:Information Networking
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    • v.37 no.6
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    • pp.459-465
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    • 2010
  • Mobile IPv6(MIPv6) features have several defects such as overloading of nodes, loss of wireless signals, packet loss, movement problem and so forth. Proxy Mobile IPv6 (PMIPv6) got over the limit of MIPv6 problems. MIPv6 features have several defects such as overloading of nodes, loss of wireless signals, packet loss, movement problem and so forth. Research on PMIPv6, which features network-based mobility is actively in progress in order to resolve these issues. PMIPv6 is emerging as a new paradigm that can overcome the limitations of the existing MIPv6. Nevertheless, such PMIPv6 also incurs problems during hand-over. While it offers a solution to node-based problems, it does, too, create long delay times during hand-over. Since MN (Mobile Node) has been sensing its own movements on MIPv6, fast handover can be done easily. However it can't apply fast handover like MIPv6, as it can't apply fast handover like MIPv6 In this paper, the author solved hand-over problem on MIPv6. MAG knows location information of MN and if MN moves into other MAG's area, Location Server gives MN information to the MAG. Therefore, this mechanism makes hand-over process easier.

Raloxifene Induces Autophagy-Dependent Cell Death in Breast Cancer Cells via the Activation of AMP-Activated Protein Kinase

  • Kim, Dong Eun;Kim, Yunha;Cho, Dong-Hyung;Jeong, Seong-Yun;Kim, Sung-Bae;Suh, Nayoung;Lee, Jung Shin;Choi, Eun Kyung;Koh, Jae-Young;Hwang, Jung Jin;Kim, Choung-Soo
    • Molecules and Cells
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    • v.38 no.2
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    • pp.138-144
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    • 2015
  • Raloxifene is a selective estrogen receptor modulator (SERM) that binds to the estrogen receptor (ER), and exhibits potent anti-tumor and autophagy-inducing effects in breast cancer cells. However, the mechanism of raloxifene-induced cell death and autophagy is not well-established. So, we analyzed mechanism underlying death and autophagy induced by raloxifene in MCF-7 breast cancer cells. Treatment with raloxifene significantly induced death in MCF-7 cells. Raloxifene accumulated GFP-LC3 puncta and increased the level of autophagic marker proteins, such as LC3-II, BECN1, and ATG12-ATG5 conjugates, indicating activated autophagy. Raloxifene also increased autophagic flux indicators, the cleavage of GFP from GFP-LC3 and only red fluorescence-positive puncta in mRFP-GFP-LC3-expressing cells. An autophagy inhibitor, 3-methyladenine (3-MA), suppressed the level of LC3-II and blocked the formation of GFP-LC3 puncta. Moreover, siRNA targeting BECN1 markedly reversed cell death and the level of LC3-II increased by raloxifene. Besides, raloxifene-induced cell death was not related to cleavage of caspases-7, -9, and PARP. These results indicate that raloxifene activates autophagy-dependent cell death but not apoptosis. Interestingly, raloxifene decreased the level of intracellular adenosine triphosphate (ATP) and activated the AMPK/ULK1 pathway. However it was not suppressed the AKT/mTOR pathway. Addition of ATP decreased the phosphorylation of AMPK as well as the accumulation of LC3-II, finally attenuating raloxifene-induced cell death. Our current study demonstrates that raloxifene induces autophagy via the activation of AMPK by sensing decreases in ATP, and that the overactivation of autophagy promotes cell death and thereby mediates the anti-cancer effects of raloxifene in breast cancer cells.

Oil Spill Detection Mechanism using Single-wavelength LED and CCD (단일 파장의 LED와 CCD를 이용한 유출유 탐지방법)

  • Oh, Sangwoo;Lee, Moonjin
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.15 no.4
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    • pp.323-329
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    • 2012
  • In this study, a new optical method for oil detection using an analysis the light-absorption image of separate oil-water mixture with a LED illumination is described. To obtain an information about the presence of oil on water and the thickness of oil, the intensity of light-absorption images acquired through CCD is analyzed. To select the optimal wavelength of the light source, the experiment is conducted using several LEDs having four different wavelength. In the case of using a blue LED having 465 nm wavelength, an intensity decreasing tendency of light-absorption image is obvious and clear. To identify the applicability of sensing system at the real sea condition, experiments are conducted as varying the brightness and water surface angle. Through this research, new optical oil detection methodology is proposed using the absorption difference between water and oil with single-wavelength LED and CCD.

Prolonged Exposure to Lipopolysaccharide Induces NLRP3-Independent Maturation and Secretion of Interleukin (IL)-1β in Macrophages

  • Hong, Sujeong;Yu, Je-Wook
    • Journal of Microbiology and Biotechnology
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    • v.28 no.1
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    • pp.115-121
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    • 2018
  • Upon sensing of microbial infections or endogenous danger signals in macrophages, inflammasome signaling plays a significant role in triggering inflammatory responses via producing interleukin (IL)-$1{\beta}$. Recent studies revealed that active caspase-1, a product of the inflammasome complex, causes maturation of inactive pro-IL-$1{\beta}$ into the active form. However, the underlying mechanism by which this leaderless cytokine is secreted into the extracellular space remains to be elucidated. In this study, we demonstrated that prolonged lipopolysaccharide (LPS) treatment to macrophages could trigger the unexpected maturation and extracellular release of IL-$1{\beta}$ through a nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3)-independent manner. Short-term treatment (less than 6 h) of LPS induced robust production of the IL-$1{\beta}$ precursor form inside cells but did not promote the maturation and secretion of IL-$1{\beta}$ in bone marrow-derived macrophages or peritoneal macrophages. Instead, prolonged LPS treatment (more than 12 h) led to a significant release of matured IL-$1{\beta}$ with no robust indication of caspase-1 activation. Intriguingly, this LPS-triggered secretion of IL-$1{\beta}$ was also observed in NLRP3-deficient macrophages. In addition, this unexpected IL-$1{\beta}$ release was only partially impaired by a caspase-1 and NLRP3 inflammasome inhibitor. Collectively, our results propose that prolonged exposure to LPS is able to drive the maturation and secretion of IL-$1{\beta}$ in an NLRP3 inflammasome-independent manner.

A Case of Vestibulopathy With Vertigo (전정 신경병증 환자 치험 1례에 대한 고찰)

  • Yu, Mi-Kyung;Choi, Jung-Hwa;Kim, Jong-Han;Park, Su-Yeon;Park, Yong-Ho
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.18 no.2
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    • pp.93-98
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    • 2005
  • Vertigo occurs when there is conflict between the signals sent to the brain by various balance- and position-sensing systems of the body. Injury to or diseases of the inner ear can send false signals to the brain indicating that the balance mechanism of the inner ear (labyrinth) detects motion. Inner ear disorders, such as benign paroxysmal positional vertigo (BPPV), Meniere's disease, vestibular neuronitis, or labyrinthitis. Vestibular neuronitis is an inflammation of the vestibular nerve, which is located in your inner ear. In this case, She has vertigo occured suddenly and continued even when the person lies completely still. It may be accompanied by nausea and vomiting. She has taken herbal medication and treated by acupunture. Her symptoms become disappeared after 3 days and All most symptoms were disappeard. In conclusion, It is required to classify vestibulopathy into vestibular neuronitis or labyrinthitis. In this case we diagnosed her case as vestibular neuronitis. Her symptoms of vestibulopathy recovered fast by Korean traditional medical therapy.

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Implementation on the Portable Blood Gas Analyzer and Performance Estimation (휴대형 혈액가스분석 시스템의 구현 및 성능평가)

  • Jeong, Do-Un;Jeon, Gye-Rok;Bae, Jin-Woo;Kim, Gil-Jung;Sim, Yoon-Bo
    • Journal of Sensor Science and Technology
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    • v.12 no.1
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    • pp.34-43
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    • 2003
  • In this study, we implemented the measurement of pH, $pO_2$, $pCO_2$ of the arterial blood on a portable blood gas analysis system. This system is consist of two parts of hardware and software. The hardware part is divided into a fluidic mechanism and an electronic circuit unit. The system program is composed of operating, washing, correcting, and measuring routines. Both of 1-point and 2-point calibration schemes were used to enhance the accuracy of the measurement. In order to evaluate the performance of the developed system, we measured and performed statistical analysis on the characteristics of the sensing electrode response. As a result, coefficient variation was within 1.12, and maximum error was within 1.298%. We confirmed development possibility of portable blood gas analyzer.

CUCE: clustering protocol using node connectivity and node energy (노드 연결도와 에너지 정보를 이용한 개선된 센서네트워크 클러스터링 프로토콜)

  • Choi, Hae-Won
    • Journal of Korea Society of Industrial Information Systems
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    • v.17 no.4
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    • pp.41-50
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    • 2012
  • Network life time is very important issue for wireless sensor network(WSN). It is very important to design sensor networks for sensors to utilize their energies in effective ways. A-PEGASIS that basically bases on PEGASIS and enhances in two aspects-an elegant chain generation algorithm and periodical update of chains. However, it has problems in the chain generation mechanism and some possibility of network partitioning or sensing hole problem in the network, in LEACH related protocols. This dissertation proposes a new clustering protocol to solve the co-shared problems in the previous protocols. The basic idea of our scheme is using the table for node connectivity. The results show that the network life time would be extended in about 1.8 times longer than LEACH and 1.5 times longer than PEGASIS-A.

Transcript accumulation of carotenoid biosynthesis genes in the cyanobacterium Synechocystis sp. PCC 6803 during the dark-to-light transition is mediated by photosynthetic electron transport

  • Ryu, Jee-Youn;Song, Ji-Young;Chung, Young-Ho;Park, Young-Mok;Chow, Wah-Soon;Park, Youn-Il
    • Plant Biotechnology Reports
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    • v.4 no.2
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    • pp.149-155
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    • 2010
  • Expression of the genes for carotenoid bio-synthesis (crt) is dependent on light, but little is known about the underlying mechanism of light sensing and signalling in the cyanobacterium Synechocystis sp. PCC 6803 (hereafter, Synechocystis). In the present study, we investigated the light-induced increase in the transcript levels of Synechocystis crt genes, including phytoene synthase (crtB), phytoene desaturase (crtP), ${\zeta}$-carotene desaturase (crtQ), and ${\beta}$-carotene hydroxylase (crtR), during a darkto-light transition period. During the dark-to-light shift, the increase in the crt transcript levels was not affected by mutations in cyanobacterial photoreceptors, such as phytochromes (cph1, cph2 and cph3) and a cryptochrome-type photoreceptor (ccry), or respiratory electron transport components NDH and Cyd/CtaI. However, treatment with photosynthetic electron transport inhibitors significantly diminished the accumulation of crt gene transcripts. Therefore, the light induction of the Synechocystis crt gene expression is most likely mediated by photosynthetic electron transport rather than by cyanobacterial photoreceptors during the dark-to-light transition.

Dynamic Threads Stack Management Scheme for Sensor Operating Systems under Space-Constrained (공간 제약하의 센서 운영체제를 위한 동적 쓰레드 스택관리 기법)

  • Yi, Sang-Ho;Cho, Yoo-Kun;Hong, Ji-Man
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.11
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    • pp.572-580
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    • 2007
  • Wireless sensor networks are sensing, computing and communication infrastructures that allow us to monitor, instrument, observe, and respond to phenomena in the harsh environment. Generally, the wireless sensor networks are composed of many deployed sensor nodes that were designed to be very cost-efficient in terms of production cost. For example, UC Berkeley's MICA motes have only 8-bit CPU, 4KB RAM, and 128KB FLASH memory space. Therefore, sensor operating systems that run on the sensor nodes should be able to operate efficiently in terms of the resource management. In this paper, we present a dynamic threads stack management scheme for space-constrained and multi-threaded sensor operating systems. In this scheme, the necessary stack space of each function is measured on compile-time. Then, the information is used to dynamically allocate and release each function's stack space on run-time. It was implemented in Nano-Qplus sensor operating system. Our experimental results show that the proposed scheme outperforms the existing fixed-size stack allocation mechanism.

Study for Chronic Diseases Patients Management System using Zigbee of based WPAN (WPAN 기반의 Zigbee를 이용한 만성질환 환자 관리 시스템에 관한 연구)

  • Park, Hung-Bog;Seo, Jung-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.4
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    • pp.965-972
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    • 2011
  • As an aged population has increased in Korea, the number of patients with chronic disease has soared up as well. The rapid increase of the chronic disease triggers a need of new paradigm of healthcare. In terms of data transmission of healthcare system, a use of data-transmission protocol based on bluetooth could be dismal in application of healthcare due to its postponement of connection. On the contrary, WPAN is evaluated to be proper to support the application of healthcare in restricted geographic areas. In addition, the bluetooth, a base of the current wireless network, doesn't support a special mechanism to cope up with emergent patients because of its delayed connection among devices. Against this backdrop, this study aims to design an integrated interface of multi bio-sensing and suggest a measuring and monitering system for the patients with chronic illnesses by using Zigbee of WPAN as a sufficient bandwidth is anticipated owing to frequent deliveries of complicated biological signals.