Karyotype Analysis of Parthenote ⇔ Tetraploid Chimeric Blastocysts in Mice

MUKAI, M.,TAKAHASHI, J.,YASUDA, Y.,강민수 濟州大學校 農科大學 動物科學硏究所 1997 動物科學論叢 Vol.12 No.1

Parthenote ⇔ tetraploid chuneric embryos were produced by aggregation of a parthenogenetically activated embryo and a tetraploid embryo. The karyotype of these chimeric embryos were observed 48h after aggregation of embryos. Tetraploid embryos were produced by electrofusion at the 2-cell stage, and about 64% of these embryos developed to blastccysts. Parthenogenetic embryos were obtained by ethanol treatment. Eggs with second polar bodies were selected as haploid parthenogenetically activated embryos. The rate of activation was 71%, and 63% of these activated ova developed to 8-cell stage embryos. Thuty-six percent of haploid parthenote ⇔ tetraploid chimeric embryos developed to blastcysts. Chromosomal analysis of chmeric embryos showed that these embryos were consisted of haploid (n) ⇔ diploid (2n), diploid (2n) ⇔ tetraploid (4n), only haploid(n), only dploid(2n) and only tetraploid chromosome constitution. These results suggested the following three points. Firstly, parthenote ⇔ tetraploid chimeric embryos can develop to blastocysts, secondly, parthenogenetic or tetraploid cell may diploidize spontaneously, and thudly, diploid cell ratio increased with the numbers of cells per blastocyst.

Perpendicular Magnetic Anisotropy of (Fe, Co)-Rare Earth Amorphous alloy Films

Miyazaki,T.,Takahashi,M. 대한금속재료학회(대한금속학회) 1989 대한금속·재료학회지 Vol.27 No.3

Perpendicular magnetic anisotropy has been studied for (M_(100-x)R_x) (M = Fe, Co, R =Pr, Nd, Sm, Gd, Dy, Er) amorphous alloy films. It is found that the perpendicular magnetic anisotropy of amorphous films consists of two terms which are proportional to the content and to the square of content of rare earths. Both of these terms can be explained by a large one ion anisotropy of rare earths.

A hump-backed trend in bacterial diversity with elevation on Mount Fuji, Japan.

Singh, Dharmesh,Takahashi, Koichi,Kim, Mincheol,Chun, Jongsik,Adams, Jonathan M Springer-Verlag 2012 Microbial ecology Vol.63 No.2

<P>Little is known of how bacterial diversity in soils varies with elevation. One previous study found a decline with elevation, whereas another found no trend. We chose Mount Fuji of Japan as a geologically and topographically simple mountain system. Samples were taken at elevational intervals, between the base of the mountain at 1,000 m and its summit at 3,700 m. Polymerase chain reaction-amplified soil DNA for the bacterial 16S gene targeting V1-V3 region was pyrosequenced using the 454 Roche machine, and taxonomically classified with reference to a bioinformatic database. There was a significant 'peak' in total bacterial diversity at around 2,500 m above the tree line with a decline towards the highest elevations around 3,700 m near the summit. Individual bacterial phyla show distinct trends-increase, decrease, or a mid-elevational 'bulge' in diversity. Bacterial diversity does not parallel woody plant or herbaceous plant diversity. We suggest that beyond the tree and vegetation line, the more extreme temperature fluctuations, stronger UV, lack of nutrients, and more frequent disturbance of the loose substrate of these slopes allows less competition and greater bacterial species diversity due to 'lottery' recruitment. However, at the highest elevations, the physiological challenges are so extreme that fewer bacterial species are capable of surviving.</P>

Three major dietary patterns are all independently related to the risk of obesity among 3760 Japanese women aged 18–20 years

Okubo, H,Sasaki, S,Murakami, K,Kim, M K,Takahashi, Y,Hosoi, Y,Itabashi, M Nature Publishing Group 2008 International Journal of Obesity Vol.32 No.3

Objective:To examine associations between dietary patterns and obesity.Design:Cross-sectional study.Subjects:A total of 3760 Japanese female dietetic course students aged 18–20 years from 53 institutions in Japan.Measurements:Diet was assessed over a 1-month period with a validated self-administered diet history questionnaire with 148 food items, from which 30 food groups were created and entered into a factor analysis. Body mass index (BMI) was calculated from self-reported body height and weight.Results:Mean BMI (±s.d.) was 20.9±2.8 kg m<SUP>−2</SUP>. Four dietary patterns were identified. After adjustment for several confounding factors and total energy intake, the ‘Healthy’ pattern, characterized by high intakes of vegetables, mushrooms, seaweeds, potatoes, fish and shellfish, soy products, processed fish, fruit and salted vegetables, was significantly associated with a lower risk of BMI25 (odds ratio of the highest quintile vs lowest, 0.57; 95% confidence interval: 0.37–0.87; P for trend <0.05). In contrast, the ‘Japanese traditional’ pattern, characterized by high intakes of rice, miso soup and soy products, and the ‘Western’ pattern, characterized by high intakes of meats, fats and oils, seasonings, processed meats and eggs, were both significantly associated with an increased risk of BMI25 (OR: 1.77; 95% CI: 1.17–2.67; P for trend <0.01 and OR: 1.56; 95% CI: 1.01–2.40; P for trend=0.04, respectively).Conclusion:Three major dietary patterns, Healthy, Japanese traditional and Western, were all independently and significantly related to the risk of obesity even among a relatively lean young Japanese female population.International Journal of Obesity (2008) 32, 541–549; doi:10.1038/sj.ijo.0803737; published online 25 September 2007

Extremely Bendable, High-PerformanceIntegrated CircuitsUsing Semiconducting Carbon Nanotube Networks for Digital, Analog,and Radio-Frequency Applications

Wang, Chuan,Chien, Jun-Chau,Takei, Kuniharu,Takahashi, Toshitake,Nah, Junghyo,Niknejad, Ali M.,Javey, Ali American ChemicalSociety 2012 Nano letters Vol.12 No.3

<P>Solution-processed thin-films of semiconducting carbonnanotubesas the channel material for flexible electronics simultaneously offershigh performance, low cost, and ambient stability, which significantlyoutruns the organic semiconductor materials. In this work, we reportthe use of semiconductor-enriched carbon nanotubes for high-performanceintegrated circuits on mechanically flexible substrates for digital,analog and radio frequency applications. The as-obtained thin-filmtransistors (TFTs) exhibit highly uniform device performance withon-current and transconductance up to 15 μA/μm and 4 μS/μm.By performing capacitance–voltage measurements, the gate capacitanceof the nanotube TFT is precisely extracted and the corresponding peakeffective device mobility is evaluated to be around 50 cm<SUP>2</SUP>V<SUP>–1</SUP>s<SUP>–1</SUP>. Using such devices, digitallogic gates including inverters, NAND, and NOR gates with superiorbending stability have been demonstrated. Moreover, radio frequencymeasurements show that cutoff frequency of 170 MHz can be achievedin devices with a relatively long channel length of 4 μm, whichis sufficient for certain wireless communication applications. Thisproof-of-concept demonstration indicates that our platform can serveas a foundation for scalable, low-cost, high-performance flexibleelectronics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2012/nalefd.2012.12.issue-3/nl2043375/production/images/medium/nl-2011-043375_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl2043375'>ACS Electronic Supporting Info</A></P>

Influence of Roller Speed on Magnetic Properties and Structures of α-Fe / Nd₂Fe₁₄B Nanocomposite Magnets Prepared by Melt - spinning

Wenli Pei,Fazeng Lian,Meng Fu,Guiqin Zhou,M. Takahashi 한국자기학회 2004 Journal of Magnetics Vol.9 No.4

The crystallization behaviours of nanocomposite made by a function of quenching rate (roller speed) were studied. The results showed that there was one step crystallization process for the alloy quenched at roller speed of 32 ㎧, which could be shown as, Am (amorphouse) + α-Fe+Nd₂Fe₁₄B → α-Fe+Nd₂Fe₁₄B. For the alloy quenched at roller speed of 40 ㎧, there was two steps crystallization process taking place at different temperatures, which could be shown as, Am → α-Fe+Nd₂Fe₂₃B₃+Nd₂Fe₁₄B+Am' → α-Fe+Nd₂Fe₁₄B. The presence of transition phase (Nd₂Fe₂₃B₃) was harmful to get fine and uniform grain size during crystallization process. Uniform microstructures and high magnetic properties could be attained for the as-quenched alloy containing less amorphous phase and no presence of transition phase during annealing treatment. For the alloy prepared at roller speed of 32 m/s, the following properties were obtained, Br = 0.904 T, iHc = 801 ㎄/m, (BH)max = 122 kJ/㎥ and Mr/Ms = 0.6.

Probing ΛΛ Potential

C. J. Yoon,H. Akikawa,K. Aoki,Y. Fukao,H. Funahashi,M. Hayata,K. Imai,K. Miwa,H. Okada,N. Saito,H. D. Sato,K. Shoji,H. Takahashi,K. Taketani,J. Asai,M. Kurosawa,M. Ieiri,T. Hayakawa,T. Kishimoto,A. Sa 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

We determined scattering length and effective range of ΛΛ scattering for the ΛΛ relative energy (M_(ΛΛ)-2M_Λ) from ΛΛ threshold to 30 MeV/c_2. Phase shift of the ΛΛ wave function which described by scattering length and effective range was determined by fitting the ΛΛ mass spectrum. The obtained scattering length -0.10^(+0.37)_(-1.56) ± 0.04, and effective range 13.90 ^(+14.35)_(-9.13) ± 10.53 fm is the most consistent with the values predicted by using a series of the Nijmegen soft core models NSC97's. However the predicted values by using the Nijmegen hard core model ND (G-matrix), the extended soft core model ESC00, and the Kyoto-Niigata FSS are out of three standard deviations from the determined scattering parameters. Further, we determine ΛΛ potential by fitting the ΛΛ invariant mass spectrum using numerically solved ΛΛ wave function with two-Gaussian shaped potential well. The ΛΛ scattering parameters derived from the wave function are found to be scattering length -0.09, and effective range 29.34 fm with a maximum phase shift of 2.4 deg.

High polarization degree of the continuum of comet 2P/Encke based on spectropolarimetric signals during its 2017 apparition

Kwon, Y. G.,Ishiguro, M.,Shinnaka, Y.,Nakaoka, T.,Kuroda, D.,Hanayama, H.,Takahashi, J.,Baar, S.,Saito, T.,Kawabata, M.,Uemura, M.,Morokuma, T.,Murata, K. L.,Takagi, S.,Morihana, K.,Nagayama, T.,Sekig Springer-Verlag 2018 Astronomy and astrophysics Vol.620 No.-

<P><I>Context.</I> Spectropolarimetry is a powerful technique for investigating the physical properties of gas and solid materials in cometary comae without mutual contamination, but only a few spectropolarimetric studies have been conducted to extract each component.</P><P><I>Aims.</I> We attempt to derive the continuum (i.e., scattered light from dust coma) polarization degree of comet 2P/Encke, free of the influence of molecular emissions. The target is unique in that its orbit is dynamically decoupled from Jupiter, like the main-belt asteroids, but it ejects gas and dust like ordinary comets.</P><P><I>Methods.</I> We observed the comet using the Hiroshima Optical and Near-Infrared Camera attached to the Cassegrain focus of the 150 cm Kanata telescope on UT 2017 February 21 when the comet was at the solar phase angle of <I>α</I> = 75°.7.</P><P><I>Results.</I> We find that the continuum polarization degree with respect to the scattering plane is <I>P</I>cont, r = 33.8 ± 2.7% at the effective wavelength of 0.82 <I>μ</I>m, which is significantly higher than those of cometary dust in a high-<I>P</I>max group at similar phase angles. Assuming that an ensemble polarimetric response of the dust of 2P/Encke as a function of phase angle is morphologically similar with those of other comets, its maximum polarization degree is estimated to <I>P</I>max ≳ 40% at <I>α</I>max ≈ 100°. In addition, we obtain the polarization degrees of the C2 swan bands (0.51-0.56 <I>μ</I>m), the NH2<I>α</I> bands (0.62-0.69 <I>μ</I>m), and the CN-red system (0.78-0.94 <I>μ</I>m) in a range of 3-19%, which depend on the molecular species and rotational quantum numbers of each branch. The polarization vector is aligned nearly perpendicularly to the scattering plane with an average of 0°.4 over a wavelength range of 0.50-0.97 <I>μ</I>m.</P><P><I>Conclusions.</I> From the observational evidence, we conjecture that the high polarization degree of 2P/Encke might be attributable to a dominance of large dust particles around the nucleus, which have remained after frequent perihelion passages near the Sun.</P>

Angular Dependence of Exchange Bias and Coercive Field in CoFe/MnIr Epitaxial Bilayers

Kim, D.Y.,Kim, C.G.,Kim, C.-O.,Shibata, M.,Tsunoda, M.,Takahashi, M.,Kim, D.Y.,Kim, C.G.,Kim, C.-O.,Shibata, M.,Tsunoda, M.,Takahashi, M. IEEE 2005 IEEE transactions on magnetics Vol.41 No.10

We have measured the hysteresis loop and torque curves at various applied magnetic field angle in CoFe/MnIr epitaxial bilayers on single crystal MgO

Genetic Structure of Mongolian Goat Populations Using Microsatellite Loci Analysis

Takahashi, H.,Nyamsamba, D.,Mandakh, B.,Zagdsuren, Yo.,Amano, T.,Nomura, K.,Yokohama, M.,Ito, S.,Minezawa, M. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.7

We studied genetic diversity and relationships among Mongolian goat populations on the basis of microsatellite DNA polymorphisms. DNA samples from eight populations (Bayandelger, Ulgii Red, Zavkhan Buural, Sumber, Zalaajinst White, Erchim Black, Dorgon, and Gobi Gurvan Saikhan) from geographically distinct areas of Mongolia were analyzed by using 10 microsatellite DNA markers. Since the 10 markers were highly polymorphic, the genetic characteristics of these native goat populations could be estimated. Genetic diversity within populations, as estimated by the expected heterozygosities, was high, ranging from 0.719 to 0.746, but genetic differentiation between populations was low, representing only 1.7% of the total genetic variation. The results suggest that Mongolian native goat populations still have a semi-wild genetic structure reflecting traditional Mongolian nomadism and the short history of artificial selection. The genetic relationships among the populations were not clear in the neighbor-joining tree generated from the modified Cavalli-Sforza chord genetic distances. By using principal components analysis, the five core populations of Mongolian native goats (Bayandelger, Ulgii Red, Zavkhan Buural, Sumber, and Dorgon) and the populations crossed with Russian breeds (Zalaajinst White, Erchim Black, and Gobi Gurvan Saikhan) were distinguished. There was no correlation between genetic relationships among the populations and the geographical distribution of the populations.