• 제목/요약/키워드: over-activation

검색결과 860건 처리시간 0.028초

파킨슨 환자들의 질병등급척도가 보행 시 하지의 근육활동에 미치는 영향 (Effects of Hoehn-Yahr Scale on the Activation of Lower-Extremity Muscles during Walking with Parkinson's Patients)

  • 김창환;김미영;문제헌;임비오
    • 한국운동역학회지
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    • 제24권3호
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    • pp.287-293
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    • 2014
  • The purpose of this study was to investigate the effects of Hoehn-Yahr scale on the activation of lower-extremity muscles during walking. Electromyography (EMG) analysis was carried out on 36 patients with Parkinson's disease in the off phase of the medication cycle. We recorded EMG signals of the tibialis anterior (TA), medial gastrocnemius (MG), lateral gastrocnemius (LG), soleus (SOL), rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST) and biceps femoris (BF) using Noraxon 16 channels EMG system during walking at preferred speed. Rectified EMG signals were normalized to reference voluntary contractions (RVC) over a gait cycle at the preferred speed, allowing for an assessment of how the activity was distributed over the gait cycle. Compared to the H & Y Scale 1, H & Y Scale 3 exhibited greater activation of the vastus lateralis during mid-stance and greater activation of the medial gastrocnemius during terminal swing. Compared to the H & Y Scale 1, H & Y Scale 2 and 3 exhibited less activation of the tibialis anterior during initial swing. We conclude that the more Hoen & Yahr Scale increase, the more abnormal lower-extremity muscles activation.

Activation of the Caprine ${\beta}$-Lactoglobulin Gene Promoter by Lactogenic Hormones in Cultured Mammary HC11 Cells

  • 김재민;유명희;김경진
    • Animal cells and systems
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    • 제1권4호
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    • pp.603-608
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    • 1997
  • Analysis of the 5'-regulatory sequence of the caprine ${\beta}$-lactoglobulin (BLG) gene promoter revealed that two different types of activation were mediated by discrete regions, from -740 to -470 and from -205 to 109, in cultured mammary HC11 cells. Activation mediated by the proximal region was observed regardless of cell growth status. Distal activation, however, was observed only after confluent growth of the cells and was enhanced by the lactogenic hormones. This activation was accompanied by appearance of binding activity of proteins to these regions in the mammary HC11 cells. The binding motifs were broadly distributed over the upstream regulatory sequence. Comparison of the binding regions and mutation analysis suggest that a binding motif homologous to the ${\gamma}$-interferon responsive element (${\gamma}$-IRE) is responsible for transcriptional activation by hormonal induction in the mammary HC11 cells. The multiple ${\gamma}$-IRE homologous motifs seem to play a significant role in enhancing mammary cell-specific activation of the caprine BLG gene.

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Evolutionary Model of Depression as an Adaptation for Blocked Social Mobility

  • Park, Hanson;Pak, Sunyoung
    • 생물정신의학
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    • 제29권1호
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    • pp.1-8
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    • 2022
  • Objectives In regard to the social competition hypothesis, depression is viewed as an involuntary defeat strategy. A previous study has demonstrated that adaptation in microenvironments can result in a wide range of behavioural patterns including defense activation disorders. Using a simulation model with evolutionary ecological agents, we explore how the fitness of various defence activation traits has changed over time in different environments with high and low social mobility. Methods The Evolutionary Ecological Model of Defence Activation Disorder, which is based on the Marginal Value Theorem, was used to examine changes in relative fitness for individuals with defensive activation disorders after adjusting for social mobility. Results Our study examined the effects of social mobility on fitness by varying the d-values, a measure of depression in the model. With a decline in social mobility, the level of fitness of individuals with high levels of defense activation decreased. We gained insight into the evolutionary influence of varying levels of social mobility on individuals' degrees of depression. In the context of a highly stratified society, the results support a mismatch hypothesis which states that high levels of defence are detrimental. Conclusions Despite the fact that niche specialization in habitats composed of multiple microenvironments can result in diverse levels of defensive activation being evolutionary strategies for stability, decreased social mobility may lead to a decrease in fitness of individuals with highly activated defence modules. There may be a reason behind the epidemic of depression in modern society.

Calpains and Apoptosis

  • Tagliarino, Colleen;Pink, John J.;Boothman, David A.
    • Animal cells and systems
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    • 제5권4호
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    • pp.267-274
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    • 2001
  • Calpains are a family of cysteine proteases existing primarily in two forms designated by the $Ca^{2+}$ concentration needed for activation in vitro, $\mu$-calpain (calpain-I) and m-calpain (calpain-II). The physiologica1 roles of calpains remain unclear. Many groups have proposed a role for calpains In apoptosis, but their patterns of activation are not well characterized. Calpains have been implicated in neutrophil apoptosis, glucocorticoid-induced thymocyte apoptosis, as well as many other apoptotic pathways. Calpain activation in apoptosis is usually linked upstream or downstream to caspase activation, or in a parallel pathway alongside caspase activation. Calpains have been suggested to be involved in DNA fragmentation (via endonuclease activation), but also as effector proteases that cleave cellular proteins involved in DNA repair, membrane associated proteins and other homeostatic regulatory proteins. Recently, our laboratory demonstrated $\mu$-calpain activation in NAD(P)H: quinone oxidoreducatse 1 (NQO1)-expressing cells after exposure to $\beta$-lapachone, a novel quinone and potential chemo- and radio-therapeutic agent. Increased cytosolic $Ca^{2+}$ in NQO1-expressing cells after $\beta$-lapachone exposures were shown to lead to $\mu$-calpain activation. In turn, $\mu$-calpain activation was important for substrate proteolysis and DNA fragmentation associated with apoptosis. Upon activation, $\mu$-calpain translocated to the nucleus where it could proteolytically cleave PARP and p53. We provided evidence that $\beta$-lapachone-induced, $\mu$-calpain stimulated, apoptosis did not involve any of the known caspases; known apoptotic caspases were not activated after $\beta$-lapachone treatment of NQO1-expressing cells, nor did caspase inhibitors have any effect on $\beta$-1apachone-induced cell death. Elucidation of processes by which $\beta$-1apachone-stimulated $\mu$-calpain activation and calpains ability to activate endonucleases and induce apoptosis independent of caspase activity will be needed to further develop/modulate $\beta$-lapachone for treatment of human cancers that over-express NQO1.

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The Effect of Hyperparameter Choice on ReLU and SELU Activation Function

  • Kevin, Pratama;Kang, Dae-Ki
    • International journal of advanced smart convergence
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    • 제6권4호
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    • pp.73-79
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    • 2017
  • The Convolutional Neural Network (CNN) has shown an excellent performance in computer vision task. Applications of CNN include image classification, object detection in images, autonomous driving, etc. This paper will evaluate the performance of CNN model with ReLU and SELU as activation function. The evaluation will be performed on four different choices of hyperparameter which are initialization method, network configuration, optimization technique, and regularization. We did experiment on each choice of hyperparameter and show how it influences the network convergence and test accuracy. In this experiment, we also discover performance improvement when using SELU as activation function over ReLU.

마그네슘 합금의 크리이프 거동에 표면처리가 미치는 영향 (The Effect of Surface Treatment on Creep Behaviors of Mg Alloy)

  • 강대민;안정오;강민철
    • 소성∙가공
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    • 제18권4호
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    • pp.347-353
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    • 2009
  • The apparent activation energy, the applied stress exponent, and rupture life have been measured from creep experiments over the range of $200^{\circ}C$ to $220^{\circ}C$ and the applied stress range of 64MPa to 94MPa. The materials were used AZ31 magnesium alloys treated by plasma electrolytic oxidation of $20{\mu}m$ and $40{\mu}m$ at surface to investigate the its influence on creep behavior, and creep tests were carried out under constant applied stress and temperature. The experimental results showed that the dipper the thickness of surface treatment the higher the activation energy and stress exponent. And the higher temperature and applied stress, the lower stress exponent and activation energy, respectively. Also the dipper the thickness of surface treatment the longer creep rupture time.

A Sperm Factor Inducing Second Polar Body Formation in Mouse Secondayy Oocyte

  • Park, Y.S;Min, S.H.
    • 한국가축번식학회지
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    • 제26권4호
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    • pp.369-375
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    • 2002
  • A sperm factor(s) for oocyte activation during fertilization has not been clearly identified. In this study to elucidate an oocyte activation factor(s), mouse sperm were sonicated and ultra-filtered with a 30 kilo-daltons (KD) cutoff membrane and the ultra-filtrate was then sequentially fractionated over Suporose 12 column and Superdex column, The recovered fractions were micro-injected into Mⅱmouse oocytes and second polar body formation (PBF) was examined. Suporose fraction RV2.10 prepared from sperm extract significantly increased PBF. Of Superdex fractions re-separated from Suporose fraction RV2.10, fraction RV2.12 also had the strongest PBF activity. By analyzing with micro-reverse phase column (URPC), the Superdex fraction RV2.12 appeared to be glutamic acid. In microinjection test, glutamic acid significantly increased PBF. This study suggests that glutamic acid should be a type of sperm factor for second polar body formation related to oocyte activation.

팔라듐 무전해 도금을 위한 활성화 처리에 대한 연구 (Activation Effect on Palladium Electroless Plating of Porous Stainless Steel Support)

  • 허장은;우상국;서동수;한성욱;한인섭;서두원
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 1999년도 춘계 학술발표회 논문집
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    • pp.165-170
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    • 1999
  • Palladium membranes have high selectivity of separation and removal of hydrogen to chemical process at high temperature. For the development of hydrogen permeable membrane, palladium was deposited on porous stainless steel support by electroless plating method. In this work, the activation effect on the surface of stainless steel support has been investigated for the effective palladium plating. The morphology and microstructure were characterized by SEM and the composition was analyzed by EDX. It is found that the composition of deposited nuclei on the stainless steel support was changed in accordance with activation cycles. It is also observed that Sn-enriched nuclei has been changed to Pd-enriched nuclei over the fifteenth activation. The uniform deposition of the dense palladium layer on porous stainless steel support has been performing with Sn-enriched nuclei and comparing with Pd-enriched nuclei.

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좀보리사초의 IgE 매개성 알레르기 반응 억제 효과 및 기전 (Carex pumila Extract Supresses Mast Cell Activation and IgE-Mediated Allergic Response in Mice)

  • 임한나;김영미
    • 한국식품위생안전성학회지
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    • 제29권4호
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    • pp.356-362
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    • 2014
  • Allergic diseases have increased rapidly over the past decades, affecting an estimated 20~30% of the population in developed countries. In this study, we investigated whether or not a typical costal sand dune plant Carex pumila (CPE) suppresses the activation of mast cells and IgE-mediated allergic response in vitro and in vivo. As the results, the extract of Carex pumila inhibited antigen-stimulated degranulation in RBL-2H3 cells and Bone marrow-derived mast cells (BMMCs), and IgE-mediated passive cutaneous anaphylaxis (PCA) in mice. CPE also suppressed the production of pro-inflammatory cytokines, TNF-${\alpha}$ and IL-4, in antigen-stimulated mast cells. As its mechanism of action, CPE inhibited the activation of Syk in $Fc{\varepsilon}RI$-mediated signalling pathway, and that of LAT, a downstream adaptor molecule of Syk, in a dose-dependent manner. CPE also suppressed the activation of mitogen-activated protein (MAP) kinases, p38, ERK1/2, JNK, and Akt. Altogether, CPE inhibited mast cell activation and IgE-mediated allergic response by antigen through suppressing the activation of Syk. These results suggest that CPE may be useful for the treatment of allergic diseases.

민첩한 활성함수를 이용한 합성곱 신경망의 성능 향상 (Performance Improvement Method of Convolutional Neural Network Using Agile Activation Function)

  • 공나영;고영민;고선우
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제9권7호
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    • pp.213-220
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    • 2020
  • 합성곱 신경망은 합성곱층과 완전연결층으로 구성되어 있다. 합성곱층과 완전연결층의 각 층에서는 비선형 활성함수를 사용하고 있다. 활성함수는 뉴런 간에 신호를 전달할 때 입력신호가 일정 기준 이상이면 신호를 전달하고 기준에 도달하지 못하면 신호를 보내지 않을 수 있는 뉴런의 정보전달 방법을 모사하는 함수이다. 기존의 활성함수는 손실함수와 관계성을 가지고 있지 않아 최적해를 찾아가는 과정이 늦어지는 점을 개선하기 위해 활성함수를 일반화한 민첩한 활성함수를 제안하였다. 민첩한 활성함수의 매개변수는 역전파 과정에서, 매개변수에 대한 손실함수의 1차 미분계수를 이용한 학습과정을 통해 최적의 매개변수를 선택하는 방법으로 손실함수를 감소시킴으로써 심층신경망의 성능을 향상시킬 수 있다. MNIST 분류문제를 통하여 민첩한 활성함수가 기존의 활성함수에 비해 우월한 성능을 가짐을 확인하였다.