• Title/Summary/Keyword: Mas1

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MAS-NMR Studies in Mixed Alkali Silicate Glasses with low Fe2O3 Content (미소량의 Fe2O3를 첨가시킨 혼합 알칼리 Silicate 유리들의 MAS-NMR 연구)

  • Kang, Myoung-Jin;Shim, Moon-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.1
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    • pp.1-14
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    • 1996
  • The mixed alkali silicate glasses doped 0.1 mol% $Fe_2O_3$ are fabricated for studying the effect of transition metal oxides, which is related to the $Li^-$ ion movement in Magic-Angle-Spinning NMR. We have investigated the spin-lattice relaxation times in the room temperature and measured the $^7Li$ MAS-NMR spectrum with temperature. When the $Fe_2O_3$ oxides are added in alkali silicate glasses, the width of spectrum is changed a little but the line shape is hardly varied. For this reason, we can think that the mixed alkali effects are shown sufficiently in the spin-spin relaxation processes. However, it is not mixed alkali effects in this case. The activation energy of $Li^-$ ions are diminished in mixed alkali glasses. From the analysis of $Li^-$ diffusion environment, spin-lattice relaxation time and the nuclear magnetization, it is confirmed that the alkali mixed effects are not shown in $^7Li$ spin-lattice relaxation processes.

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Identification Of Jet Components Of CTA 102 On Milliarcsecond Scales Using The iMOGABA Program

  • Kim, Sang-Hyun;Lee, Sang-Sung;Hodgson, Jeffrey A.;Lee, Jee Won;Kang, Sincheol;Yoo, Sung-Min
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.76.1-76.1
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    • 2019
  • CTA 102, one of gamma-ray bright active galactic nuclei (AGN) has been observed with Korean very long baseline interferometry (VLBI) network (KVN) during the period of 2012 December-2018 May as part of interferometric Monitoring Of Gamma-ray Bright AGN (iMOGABA). Multi-frequency VLBI observations enable us to compare the milliarcsecond(mas)-scale iMOGABA images of relativistic jets with those from the Monitoring Of Jets in AGN with Very long baseline array (VLBA) Experiments (MOJAVE) and the VLBA-Boston University(BU)-BLAZAR programs which use VLBA with its angular resolutions of 0.2-1.3 mas. In spite of the relative larger beam sizes of KVN (1-10 mas), we are able to identify jet components of CTA 102 using the KVN multi-frequency VLBI observations with those resolved with VLBA. Considering an instrumental beam blending effect on the jet component identification, we were able to obtain a blending shift of the core position based on a convolution analysis using the VLBA data. When we apply the core position shift to the KVN images of CTA 102, we find that the identified jet components of CTA 102 from the KVN observations are well matched with those from the VLBA observations. Based on the results of the analysis, we may be able to study the jet kinematics and its correlation with gamma-ray flare activity.

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Association of selected gene polymorphisms with thermotolerance traits in cattle - A review

  • Hariyono, Dwi Nur Happy;Prihandini, Peni Wahyu
    • Animal Bioscience
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    • v.35 no.11
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    • pp.1635-1648
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    • 2022
  • Thermal stress due to extreme changes in the thermal environment is a critical issue in cattle production. Many previous findings have shown a decrease in feed intake, milk yield, growth rate, and reproductive efficiency of cattle when subjected to thermal stress. Therefore, selecting thermo-tolerant animals is the primary goal of the efficiency of breeding programs to reduce those adverse impacts. The recent advances in molecular genetics have provided significant breeding advantages that allow the identification of molecular markers in both beef and dairy cattle breeding, including marker-assisted selection (MAS) as a tool in selecting superior thermo-tolerant animals. Single-nucleotide polymorphisms (SNPs), which can be detected by DNA sequencing, are desirable DNA markers for MAS due to their abundance in the genome's coding and non-coding regions. Many SNPs in some genes (e.g., HSP70, HSP90, HSF1, EIF2AK4, HSBP1, HSPB8, HSPB7, MYO1A, and ATP1A1) in various breeds of cattle have been analyzed to play key roles in many cellular activities during thermal stress and protecting cells against stress, making them potential candidate genes for molecular markers of thermotolerance. This review highlights the associations of SNPs within these genes with thermotolerance traits (e.g., blood biochemistry and physiological responses) and suggests their potential use as MAS in thermotolerant cattle breeding.

Solid-state NMR Studies of Miscibility and Morphology in Blends of Bisphenol-A type Polycarbonate and Poly (ester-ether) Elastomer

  • Kim, Yongae
    • Journal of the Korean Magnetic Resonance Society
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    • v.5 no.1
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    • pp.19-28
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    • 2001
  • Miscibility and morphology in blends of bisphenol-A type polycarbonate and poly (ester-ether) elastomer with different compositions are studied by solid-state NMR spectroscopy. $^{13}$ C Solid-state NMR of CP/MAS/TOSS/DD, CP/MAS/DD, inversion recovery CP/MAS/DD, and 2D rotor driven spin diffusion techniques are used to identify the miscibility, morphology, and transesterification in blends. The blends of PC /BT elastomer with 15% to 42% of soft segment seem to be single phase miscible mixing and those of PC/PBT and PC/PBT elastomer with 62% of soft segment are cocontinuous two phase immiscible mixing. No significant transesterification reactions are observed in blends with different compositions.

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Performance Comparison of Two Parallel LU Decomposition Algorithms on MasPar Machines

  • Kim, Yong-Tae
    • Journal of IKEEE
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    • v.2 no.2 s.3
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    • pp.247-254
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    • 1998
  • This paper presents a performance study of two LU decomposition algorithms on two massively parallel SIMD machines: the 16K processor MasPar MP-1 and the 4K processor MasPar MP-2. The paper presents experimental results and an analysis of the algorithms to explain the results. While the blocked and the nonblocked algorithms for LU decomposition have been studied individually by others, we compare the two algorithms and identify the tradeoffs between them. Our analysis of the blocked algorithm shows how the block size affects the interprocessor communication cost and the memory read/write overhead. The analysis in this paper is useful to determine an optimum block size for the blocked algorithm.

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The Effects of Clinical Characteristics of Chronic Stroke Patients on Physiological Cost Index During Walking (만성 뇌졸중 환자의 임상적 특성이 보행 시 생리적 부담지수에 미치는 영향)

  • Kim, Won-Ho
    • Physical Therapy Korea
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    • v.13 no.1
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    • pp.32-37
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    • 2006
  • The purpose of this study was to investigate the effects of clinical characteristics of chronic stroke patients on physiological cost index (PCI) during walking. Fourteen stroke patients participated in this study. To investigate the clinical characteristics, Fugl-Meyer score (FMS), gait velocity (GV), muscle strength of the knee extensor, modified Ashworth scale (MAS) of ankle plantar flexor, devices, and gait patterns during walking were measured and analyzed. The results were as follows: Firstly, use of devices and high MAS of the ankle plantar flexor significantly increased PCI. Secondly, PCI was significantly correlated with the FMS and MAS of the ankle plantar flexor. In conclusion, inhibition of spasticity of the ankle plantar flexor is considered to reduce PCI during walking for chronic stroke patients.

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Effects of the long-term use of maxillary protraction facemasks with skeletal anchorage on pharyngeal airway dimensions in growing patients with cleft lip and palate

  • Kim, Jung-Eun;Yim, Sunjin;Choi, Jin-Young;Kim, Sukwha;Kim, Su-Jung;Baek, Seung-Hak
    • The korean journal of orthodontics
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    • v.50 no.4
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    • pp.238-248
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    • 2020
  • Objective: To investigate the effects of the long-term use of a maxillary protraction facemask with miniplate (FM-MP) on pharyngeal airway dimensions in growing patients with cleft lip and palate (CLP). Methods: The study included 24 boys with CLP (mean age, 12.2 years; mean duration of FM-MP therapy, 4.9 years), divided into two groups according to the amount of A point advancement to the vertical reference plane (VRP): Group 1, > 4 mm; Group 2, < 2 mm; n = 12/group. After evaluating the skeletodental and airway variables using lateral cephalograms acquired before and after FM-MP therapy, statistical analyses were performed. Results: Group 1 showed greater forward and downward displacements of the posterior maxilla (posterior nasal spine [PNS]-horizontal reference plane [HRP]; PNS-VRP), greater increase in ANB, more forward tongue position (tongue tip-Pt vertical line to Frankfort horizontal plane), and greater increase in the oropharynx (superior posterior airway space [SPAS]; middle airway space [MAS]) and upper nasopharynx (PNS-adenoid2) than did Group 2. While maxillary advancement (A-VRP and PNS-VRP) correlated with increases in SPAS, MAS, and PNS-adenoid2, downward displacement of the PNS (PNS-HRP) correlated with increases in SPAS, MAS, PNS-adenoid1, and PNS-adenoid2, and with a decrease in vertical airway length (VAL). Mandibular forward displacement and decrease in mandibular plane correlated with increases in MAS. Conclusions: FM-MP therapy had positive effects on the oropharyngeal and nasopharyngeal airway spaces without increases in VAL in Group 1 rather than in Group 2. However, further validation using an untreated control group is necessary.

A Context-based Multi-Agent System for Enacting Virtual Enterprises (가상기업 지원을 위한 컨텍스트 기반 멀티에이전트 시스템)

  • Lee, Kyung-Huy;Kim, Duk-Hyun
    • The Journal of Society for e-Business Studies
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    • v.12 no.3
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    • pp.1-17
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    • 2007
  • A virtual enterprise (VE) can be mapped into a multi-agent system (MAS) that consists of various agents with specific role(s), communicating with each other to accomplish common goal(s). However, a MAS for enacting VE requires more advanced mechanism such as context that can guarantee autonomy and dynamism of VE members considering heterogeneity and complex structure of them. This paper is to suggest a context-based MAS as a platform for constructing and managing virtual enterprises. In the Context-based MAS a VE is a collection of Actor, Interaction (among Actors), Actor Context, and Interaction Context. It can raise the speed and correctness of decision-making and operation of VE enactment using context, i.e., information about the situation (e.g., goal, role, task, time, location, media) of Actors and Interactions, as well as simple data of their properties. The Context-based MAS for VE we proposed('VECoM') may consists of Context Ontology, Context Model, Context Analyzer, and Context Reasoner. The suggested approach and system is validated through an example where a VE tries to find a partner that could join co-development of new technology.

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Comparison of metabolic profiling of Daphnia magna between HR-MAS NMR and solution NMR techniques

  • Kim, Seonghye;Lee, Sujin;Lee, Wonho;Lee, Yujin;Choi, Juyoung;Lee, Hani;Li, Youzhen;Ha, Seulbin;Kim, Suhkmann
    • Journal of the Korean Magnetic Resonance Society
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    • v.25 no.2
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    • pp.12-16
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    • 2021
  • Daphnia magna is used as target organism for environmental metabolomics. The metabolome of D. magna was studied with NMR spectroscopy. Most studies used the extract of D. magna, but the reproducibility cannot be obtained using extracted sample. In this study, lyophilized D. magna samples were analyzed with two different 1H NMR techniques, HR-MAS on intact tissues and solution NMR on extracted tissues. Samples were measured three times using 600 MHz NMR spectrometer. Metabolite extraction required more than twice as many D. magna, but the metabolite intensity was lower in solution NMR. In the spectra of HR-MAS NMR, the lipid signal was observed, but they did not interfere with metabolite profiling. We also confirmed the effect of swelling time on signal intensities of metabolites in HR-MAS NMR, and the results suggest that appropriate swelling should be used in lyophilized D. magna to improve the accuracy of metabolite profiles.

Study of Metabolic Profiling Changes in Colorectal Cancer Tissues Using 1D 1H HR-MAS NMR Spectroscopy

  • Kim, Siwon;Lee, Sangmi;Maeng, Young Hee;Chang, Weon Young;Hyun, Jin Won;Kim, Suhkmann
    • Bulletin of the Korean Chemical Society
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    • v.34 no.5
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    • pp.1467-1472
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    • 2013
  • Metabolomics is a field that studies systematic dynamics and secretion of metabolites from cells to understand biological pathways based on metabolite changes. The metabolic profiling of intact human colorectal tissues was performed using high-resolution magic angle spinning (HR-MAS) NMR spectroscopy, which was unnecessary to extract metabolites from tissues. We used two different groups of samples, which were defined as normal and cancer, from 9 patients with colorectal cancer and investigated the samples in NMR experiments with a water suppression pulse sequence. We applied target profiling and multivariative statistical analysis to the analyzed 1D NMR spectra to identify the metabolites and discriminate between normal and cancer tissues. Cancer tissue showed higher levels of arginine, betaine, glutamate, lysine, taurine and lower levels of glutamine, hypoxanthine, isoleucine, lactate, methionine, pyruvate, tyrosine relative to normal tissue. In the OPLS-DA (orthogonal partial least square discriminant analysis), the score plot showed good separation between the normal and cancer groups. These results suggest that metabolic profiling of colorectal cancer could provide new biomarkers.