178 research outputs found
Discovery of Multiple High-Velocity Narrow Circumstellar Na I D Lines in Nova V1280 Sco
We discovered multiple high-velocity (ranging from -900 to -650 km/s) and
narrow (FWHM = 15 km/s) absorption components corresponding to both the D2 and
the D1 lines of Na I on a high dispersion spectrum of V1280 Sco observed on
2009 May 9 (UT), 814 d after the V-band maximum. Subsequent observations
carried out on 2009 June and July confirmed at least 11 distinct absorption
components in both systems. Some components had deepened during the two months
period while their HWHMs and wavelengths remained nearly constant. We suggest
these high velocity components originate in cool clumpy gas clouds moving on
the line of sight, produced in interactions between pre-existing cool
circumstellar gas and high velocity gas ejected in the nova explosion. The
optical region spectrum of V1280 Sco in 2009 is dominated by the continuum
radiation and exhibits no forbidden line characterizing the nebular phase of
typical novae. Permitted Fe II lines show doubly peaked emission profiles and
some strong Fe II lines are accompanied by a blue shifted (about -255 km/s)
absorption component. However, no high-velocity and narrow components
corresponding to those of Na I could be detected in Fe II lines nor in the
Balmer lines. The 255 km/s low velocity absorption component is most probably
originating in the wind from the nova.Comment: Accepted for PASJ letter, 5 pages, 8 figure
Pharmacologic Treatment with GABAB Receptor Agonist of Methamphetamine-Induced Cognitive Impairment in Mice
Methamphetamine (METH) is a highly addictive drug, and addiction to METH has increased to epidemic proportions worldwide. Chronic use of METH causes psychiatric symptoms, such as hallucinations and delusions, and long-term cognitive deficits, which are indistinguishable from paranoid schizophrenia. The GABA receptor system is known to play a significant role in modulating the dopaminergic neuronal system, which is related to behavioral changes induced by drug abuse. However, few studies have investigated the effects of GABA receptor agonists on cognitive deficits induced by METH. In the present review, we show that baclofen, a GABA receptor agonist, is effective in treating METH-induced impairment of object recognition memory and prepulse inhibition (PPI) of the startle reflex, a measure of sensorimotor gating in mice. Acute and repeated treatment with METH induced a significant impairment of PPI. Furthermore, repeated but not acute treatment of METH resulted in a long-lasting deficit of object recognition memory. Baclofen, a GABAB receptor agonist, dose-dependently ameliorated the METH-induced PPI deficits and object recognition memory impairment in mice. On the other hand, THIP, a GABAA receptor agonist, had no effect on METH-induced cognitive deficits. These results suggest that GABAB receptors may constitute a putative new target in treating cognitive deficits in chronic METH users
Matrix Metalloproteinases Contribute to Neuronal Dysfunction in Animal Models of Drug Dependence, Alzheimer's Disease, and Epilepsy
Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) remodel the pericellular environment by regulating the cleavage of extracellular matrix proteins, cell surface components, neurotransmitter receptors, and growth factors that mediate cell adhesion, synaptogenesis, synaptic plasticity, and long-term potentiation. Interestingly, increased MMP activity and dysregulation of the balance between MMPs and TIMPs have also been implicated in various pathologic conditions. In this paper, we discuss various animal models that suggest that the activation of the gelatinases MMP-2 and MMP-9 is involved in pathogenesis of drug dependence, Alzheimer's disease, and epilepsy
An intellectual genealogy graph: affording a fine prospect of organizational learning
Abstract: The word of "learning", in a wide sense, is used as a part of the social system of education and it has been attracting researchers' interest in our research area of educational systems. The goal of this research is to support creation and inheritance of organizational intellect, that is, "learning" in an organization. In this paper, we will propose an "Intellectual Genealogy Graph," which is a model representing chronological correlation among persons, activities, and intellect in an organization. The intellectual genealogy graph is a basis of intelligent functions which is useful for surveying current learning conditions and clarifying the intellectual role of individuals, organizations, and documents in the organization
薬物依存の形成機序の解明: マトリクスメタロプロテアーゼの関与
名古屋大学 / 金沢大学医薬保健研究域医学系21世紀を迎えた今日、薬物依存あるいは薬物乱用は歯止めがないまま依然としてさらなる悪化の傾向をたどっている。日本においては覚せい剤事犯の若年化が進み、薬物依存は深刻な問題であり、法的にも社会的にも、そして何よりも医学的に正しく対処する必要がある。我々は、メタンフェタミン(methamphetamine, METH)と麻薬性鎮痛薬であるモルヒネに共通した薬物依存の形成機構を解明するために、各々の薬物を連続投与したラット脳における遺伝子発現の変化をDNAアレイを用いて網羅的に解析した。その結果、細胞外マトリックスプロテアーゼ関連タンパクが大きく変動している事が示された。そこで、私は本科学研究費補助金を用いて、細胞外マトリックスプロテアーゼの一つであるmatrix metalloproteinase-2(MMP-2)、MMP-9およびその抑制因子tissue inhibitor of MMP-2(TIMP-2)の薬物依存への関わりについて検討した。その結果、METHの連続投与により、MMP-2、MMP-9、TIMP-2の発現が増加することを初めて見出した。さらに、MMP/TIMPシステムはドパミントランスポーター(DAT)やドパミン受容体機能の調節を介してMETHによる細胞外ドパミン量の増加を増強することにより、METHによる行動感作や報酬効果の調節に関与している可能性を明らかにした。近い将来、この経路に作用する選択的薬剤を開発することができれば、薬物依存を根絶することができると期待している。研究課題/領域番号:18790052, 研究期間(年度):2006 – 2007出典:「薬物依存の形成機序の解明-マトリクスメタロプロテアーゼの関与-」研究成果報告書 課題番号18790052(KAKEN:科学研究費助成事業データベース(国立情報学研究所))(https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-18790052/)を加工して作
Matrix metalloproteinases contribute to neuronal dysfunction in animal models of drug dependence, Alzheimer’s disease
Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) remodel the pericellular environment by regulating the cleavage of extracellular matrix proteins, cell surface components, neurotransmitter receptors, and growth factors that mediate cell adhesion, synaptogenesis, synaptic plasticity, and long-term potentiation. Interestingly, increased MMP activity and dysregulation of the balance between MMPs and TIMPs have also been implicated in various pathologic conditions. In this paper, we discuss various animal models that suggest that the activation of the gelatinases MMP-2 and MMP-9 is involved in pathogenesis of drug dependence, Alzheimer's disease, and epilepsy
Outbreak of Salmonella Braenderup Infection Originating in Boxed Lunches in Japan in 2008
There have been only 2 reports of a large-scale foodborne outbreak arising from Salmonella enterica serotype Braenderup infection worldwide. On August 9, 2008, an outbreak originating in boxed lunches occurred in Okayama, Japan. We conducted a cohort study of 786 people who received boxed lunches from a particular catering company and collected 644 questionnaires (response rate:82%). Cases were defined as those presenting with diarrhea (≧4 times in 24h) or fever (≧38℃) between 12 am on August 8 and 12 am on August 14. We identified 176 cases (women/men:39/137);younger children (aged<10 years) appeared to more frequently suffer severe symptoms. Three food items were significantly associated with higher risk of illness;tamagotoji (soft egg with mixed vegetables and meat) (relative risk (RR):11.74, 95% confidence interval (CI):2.98-46.24), pork cooked in soy sauce (RR:3.17, 95% CI:1.24-8.10), and vinegared food (RR:4.13, 95% CI:1.60-10.63). Among them, only the RR of tamagotoji was higher when we employed a stricter case definition. Salmonella Braenderup was isolated from 5 of 9 sampled cases and 6 food handlers. It is likely that unpasteurized liquid eggs contaminated by Salmonella Braenderup and used in tamagotoji caused this outbreak
A new digital control for forward type multiple-output dc-dc converter
The purpose of this paper is to present a new digital control method of the forward type multiple-output dc-dc converter with both the P-I-D control and the static equation model. The dynamic characteristics of digital control dc-dc converter are improved as compared with the conventional one. As a result, it is seen that the forward type multiple-output dc-dc converter with a new digital control has a superior transient response compared with that of the conventional control. The overshoot of reactor current is improved 28%.INTELEC 2009 - 2009 International Telecommunications Energy Conference : Incheon, South Korea, 2009.10.18-2009.10.2
Remarks on Phase Transitions in Matrix Models and N=1 Supersymmetric Gauge Theory
A hermitian one-matrix model with an even quartic potential exhibits a
third-order phase transition when the cuts of the matrix model curve coalesce.
We use the known solutions of this matrix model to compute effective
superpotentials of an N=1, SU(N) supersymmetric Yang-Mills theory coupled to an
adjoint superfield, following the techniques developed by Dijkgraaf and Vafa.
These solutions automatically satisfy the quantum tracelessness condition and
describe a breaking to SU(N/2) x SU(N/2) x U(1). We show that the value of the
effective superpotential is smooth at the transition point, and that the
two-cut (broken) phase is more favored than the one-cut (unbroken) phase below
the critical scale. The U(1) coupling constant diverges due to the massless
monopole, thereby demonstrating Ferrari's general formula. We also briefly
discuss the implication of the Painleve II equation arising in the double
scaling limit.Comment: 15 pages, 7 figure
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