197,377 research outputs found
WHERE DOES THE DARK HALO OF THE GALAXY END? M. Miyamoto, T. Tsujimoto
No full textWe estimate the mass and the extent of our Galaxy with a massive dark halo from extreme spatial velocities of Hipparcos RR Lyrae stars and other velocity sources. We find the most extreme velocity in the range 420--480 km s \Gamma1 for the present sample. The galactic potential dominated by the massive halo is modelled simply by a spherical logarithmic one, in which the mass distribution is truncated at a galactic boundary. Contrary to the popular concept of `escape' or `bound', we introduce another extreme condition on trapped orbits, in which no star can leak out of the galactic boundary. Then, the above range of the extreme velocity gives the boundary radius of 50 kpc \Gamma100 kpc and the total mass of 5:5 \Theta 10 11 M fi \Gamma 1:1 \Theta 10 12 M fi . Key words: Local Marginal Velocity; Galactic Boundary; Galactic Mass; Dark Halo. 1. INTRODUCTION It is known that in our Galaxy the rotation curve is approximately flat to a galactocentric distance as great as twice the solar..
Flabegraviera fujiae Jimi, Tsujimoto, Watanabe, Kakui & Kajihara, 2017, sp. nov.
No full textFlabegraviera fujiae sp. nov. (New Japanese name: Fuji-kibukure-habouki) (Figs 1–2) Type material. Holotype. NSMT-Pol-H-609. Complete (some chaetae broken, dissected), sex undetermined, nonreproductive-adult, Nishinoura (69°00.4´S, 39°34.5´E), 9 m depth, sandy mud, 16 Jan., 1981. Description. Holotype (NSMT-Pol-H-609) 9.4 cm long, 1.8 cm wide. Body fusiform, covered by very thick tunic (Fig. 1 A). Tunic transparent, gel-like, covering whole body except cephalic cage (partially eroded); sediment grains attached dorsally, ventrally, and laterally (size in long axis ~40 µm), not immersed in tunic. Body papillated; papillae long, clavate, forming sheath covering chaetae, mostly eroded. Lobe on dorsum of chaetiger 1 absent. Dorsal and ventral surface irregular. Prostomium low cone. Branchiae 6–8 rows, about 110 filaments per side, 3–5 mm long, decreasing in size ventrally, black in ethanol. Branchial plate crescent-like, bisected by well-developed caruncle (Fig. 1 B). Palps long (6 mm), cylindrical, pink in ethanol. Four black eyes present. Lateral and dorsal lips well developed; ventral lip reduced. Nephridial lobes present. Chaetigers 33 in number; chaetiger 1 comprising cephalic cage. Cephalic cage 1.6 cm long, exposed whole, about 1/5 body length (9/10 body width), comprising 39 notochaetae and 24 neurochaetae per side. Chaetal transition from cephalic cage to body abrupt. Parapodia well developed, completely covered by tunic, notopodia and neuropodia widely separated. Gonopodial lobe absent. Chaetal bundles arranged into a straight series not like F. mundata. Notochaetae of two types: 1) multiarticulated, 1.2–3.4 cm long, 5–7 per fascicle (Fig. 2 A); and 2) not multiarticulated, 3 mm long, 8–10 per fascicle (Fig. 2 B). Neurochaetae multiarticulated capillaries in chaetiger 1. Neurohooks in chaetigers 2–33 (Fig. 2 C, D), 3–5 per fascicle, anchylosed, 0.7–0.9 cm long, pale orange, covered by a cylindrical shaft; crest bending region anchylosed. Multiarticulated neurohooks absent. Posterior end exposed, truncate; last two segments achaetous; pygidium simple; no anal cirri; anus without pigment (Fig. 1 C). Etymology. The species is named after the Japanese icebreaker Fuji, utilized for the research operation during which KW collected the holotype. The derivation is made after the vessel’s name taken as a feminine proper name. The new specific name is thus a noun in the genitive case. The Japanese name literally means ‘Fuji’s thickly dressed flabelligerid’, derived from kibukure (thick-dressed) and haboukigokai (flabelligerid polychaete). Remarks. Morphologically, Flabegraviera fujiae sp. nov. resembles Flabegraviera profunda Salazar-Vallejo, 2012 because in both species the notochaetal arrangement follows a straight-line, the neurohooks are anchylosed, and the tunic carries sediment grains. However, F. fujiae can be discriminated from F. profunda by the relative size and exposure of the cephalic cage, which is exposed almost entirely in F. fujiae, whereas it is covered by the tunic in F. profunda. In addition, the cephalic cage is about 1/5 body length in F. fujiae, compared to about 1/ 10 in F. profunda. An additional difference is that F. fujiae has eyes. Our specimen was collected from a depth of 9 m, that is markedly shallower than the previous records for F. profunda, collected in sediments at 330–450 m water depth (Salazar-Vallejo 2012).Published as part of Jimi, Naoto, Tsujimoto, Megumu, Watanabe, Kentaro, Kakui, Keiichi & Kajihara, Hiroshi, 2017, A new species and the shallowest record of Flabegraviera Salazar-Vallejo, 2012 (Annelida: Flabelligeridae) from Antarctica, pp. 477-485 in Zootaxa 4221 (4) on pages 478-481, DOI: 10.11646/zootaxa.4221.4.4, http://zenodo.org/record/25250
DNS of turbulent channel flow with a flexible square cylinder
No full textFluid-Structure Interaction (FSI) problem is concerned with in various research fields such as mechanical, aerospace, civil and medical engineering. Their accurate prediction and control are desired. So far, in order to improve the performance of various applications, many kind of research, on the heat transfer enhancement due to vortex generator in heat exchangers, on the drag reduction through the setting of bluff body in pipe-line systems, and on the reduction of flow induced vibration, are conducted. In particular, since the wake of wall-mounted cylinder is a common flow regime in above-mentioned research, the detail of the flow has been aggressively investigated so far[1]. The present study, we pay attention to the flow control using flexible structures in the above mentioned flows. To investigate the potentiality of the control in advance, both high accurate and stable computational scheme is needed so that theactual phenomena including turbulence is well predicted. Therefore, in order to analyze the fluid-structure interaction, we propose aweak-coupling method[2] in which for flexible structures, the rigorous equations of motion are discretized with finite volume method (FVM[3]); for a flow computation, the finite difference method (FDM) is used and the flexible structures is reproduced via immersed boundary method[4]. In this present paper, we demonstrate on the result of flow structure around of rigid and elastic cylinder in turbulent channel flow
Evolution of the Magnetic Excitations in NaOsO3 through its Metal-Insulator Transition
Get PDFThe temperature dependence of the excitation spectrum in
NaOsO
3
through its metal-to-insulator transition (MIT) at 410 K has been investigated using resonant inelastic x-ray scattering at the Os
L
3
edge. High-resolution (
Δ
E
∼
56
meV
) measurements show that the well-defined, low-energy magnons in the insulating state weaken and dampen upon approaching the metallic state. Concomitantly, a broad continuum of excitations develops which is well described by the magnetic fluctuations of a nearly antiferromagnetic Fermi liquid. By revealing the continuous evolution of the magnetic quasiparticle spectrum as it changes its character from itinerant to localized, our results provide unprecedented insight into the nature of the MIT in
NaOsO
3
[J. G. Vale, S. Calder, C. Donnerer, D. Pincini, Y. G. Shi, Y. Tsujimoto, K. Yamaura, M. M. Sala, J. van den Brink, A. D. Christianson, and D. F. McMorrow, Phys. Rev. B 97, 184429 (2018)]
THz emission from intrinsic Josephson junctions in high-Tc superconductors for imaging applications
No full textIn 2007 [1], we have succeeded in observing strong, coherent, and continuous THz emission from a mesa of Bi 2 Sr 2 CaCu 2 O 8+s single crystal with a rectangular dimension of a few hundred micrometers in length, several tens of micrometers in width, and a few micrometers in thickness. Since then, great progress has been made both in understanding the fundamental mechanism of the radiation [2-6] and in practical applications [7-9] . References: [1] L. Ozyuzer, A. E. Koshelev, C. Kuter, N. Gopalsami, Q. Li, M. Tachiki, K. Kadowaki, T. Yamamoto, H. Minami, H. Yamaguchi, T. Tachiki, K. E. Gray, W. –K. Kwok and U. Welp, "Emission of Coherent THz Radiation from Superconductors", Science, 318, 1291 (2007). [2] K. Kadowaki, H. Yamaguchi, K. Kawamata, T. Yamamoto, H. Minami, I. Kakeya, U. Welp, L. Ozyuzer, A. Koshelev, C. Kurter, K. E. Gray and W. –K. Kwok, "Direct Observation of Terahertz Electromagnetic Waves emitted from Intrinsic Josephson Junctions in single crystalline Bi2Sr2CaCu2O8+ ", Physica C468, 634-639 (2008). [3] K. Kadowaki M. Tsujimoto, K. Yamaki, T. Yamamoto, T. Kashiwagi, H. Minami, M. Tachiki and R. A. Klemm, "Evidence for Dual- Source Mechanism of Terahertz Radiation from Rectangular Mesas of Single Crystalline Bi2Sr2CaCu2O8+ Intrinsic Josephson Junctions", J. Phys. Soc. Jpn. 79, 023703 (2010) [4] M. Tsujimoto, K. Yamaki, K. Deguchi, T. Yamamoto, T. Kashiwagi, H. Minami, M. Tachiki, K. Kadowaki, and R. A. Klemm, "Geometrical Resonance Conditions for THz Radiation from the Intrinsic Josephson Junctions in Bi2Sr2CaCu2O8+ ", Phys. Rev. Lett. 105, 037005 (2010). [5] M. Tsujimoto, T. Yamamoto, K. Delfanazari, R. Nakayama, T. Kitamura, M. Sawamura, T. Kashiwagi, H. Minami, M. Tachiki, K. Kadowaki, and R. A. Klemm, "Broadly Tunable Subterahertz Emission from Internal Branches of the Current-Voltage Characteristics of Superconducting Bi2Sr2CaCu2O8+ Single Crystals", Phys. Rev. Lett. 108, 107006 (2012). [6] T. Kashiwagi, M. Tsujimoto, T. Yamamoto, H. Minami, K. Yamaki, K. Delfanazari, K. Deguchi, N. Orita, T. Koike, R. Nakayama, T. Kitamura, M. Sawamura, S. Hagino, K. Ishida, K. Ivanovic, H. Asai, M. Tachiki, R. A. Klemm, and K. Kadowaki, "High Temperature Superconductor Terahertz Emitters: Fundamental Physics and Applications", Jpn. J. Appl. Phys. 51 (2012) 0101113. [7] H. Minami, I. Kakeya, H. Yamaguchi, T. Yamamoto, and K. Kadowaki, "Characteristics of terahertz radiation emitted from the intrinsic Josephson junctions in high-Tc superconductor Bi2Sr2CaCu2O8+ ", Appl. Phys. Lett. 95, (2009) 232511. [8] K. Yamaki, M. Tsujimoto, T. Yamamoto, A. Furukawa, T. Kashiwagi, H. Minami, and K. Kadowaki, "High-power terahertz electromagnetic wave emission from high-Tc superconducting Bi2Sr2CaCu2O8+ mesa structures", OPTICS EXPRESS 19 (2011) 3193. [9] H. Minami, M. Tsujimoto, T. Kashiwagi, T. Yamamoto, and K. Kadowaki, IEICE Trans. Electron., E95-C, (2012) 347. [10] M. Tsujimoto, H. Minami, K. Delfanazari, M. Sawamura, R. Nakayama, T. Kitamura, T. Yamamoto, T. Kashiwagi, T. Hattori and K. Kadowaki, "Terahertz imaging system using high-Tc superconducting oscillation devices", J. Appl. Phys. 111, (2012) 123111.© 2013 IEEE
Graphonema antarcticum Shimada & Tsujimoto & Watanabe 2019, sp. nov.
No full textGraphonema antarcticum sp. nov. (Figs 1–4; Table 1) Material examined. Holotype: adult male (ICHUM 5867), whole mount, 68°59′55″S, 39°35′28″E, Kita-noura, off Syowa Station in Lützow-Holm Bay, Antarctica, surface of macroalgae collected by means of bait traps at 27 m depth, 16 December 2005. Paratypes: six adult males (ICHUM 5868–5872, 5876) and five adult females (ICHUM 5873–5875, 5877, 5878), whole mounts, same collection data as with holotype. Non-type: an adult male (ICHUM 5879), Au-coated SEM specimen, same collection data as with holotype. Diagnosis. Graphonema antarcticum sp. nov. is characterized by large body size (equal to or more than 2.0 mm), truncated cephalic end, presence of lateral differentiation, long spicules (80–90 µm and 1.3–1.6 abd), without capitulum, well-developed gubernaculum with L-shaped lateral pieces bending at an obtuse angle with minute denticles at distal end, and long tail in both sexes (approximately 4–6 abd in males and 6–9 abd in females). Measurements. See Table 1. Description. Males. Body (Fig. 1A) almost cylindrical, tapering toward both ends. Epicuticle coarsely annulated (Fig. 2), except at anterior and posterior body ends (Figs. 1B, 2, 4A, G). Exocuticle with heterogeneous ornamentations (cf. Gourbault and Vincx 1994): tiny punctate at anterior half of cephalic region (Figs 1B, 4A); regularly hexagonal to posterior half of cephalic region to anterior 1/3 of pharynx (Figs 1B, C, 4A, B); longitudinally elongated hexagonal from anterior 1/3 of pharynx to cloacal region (Figs 1D, E, 4C, D), becoming longer toward posterior end; regularly hexagonal in caudal region (Figs 1F, 4F), becoming smaller toward posterior end; no ornamentation at tail end (Figs 3A, 4G). Lateral differentiation (Figs 1 C–E, 4B, C) present, beginning from anterior 1/3 of pharyngeal region to cloacal region, becoming wider toward posterior end. Cephalic region (Figs 1B, G, H, 2A, B) not set-off, truncated at anterior end. Cephalic diameter 25–30% of mbd. Inner labial sensilla inconspicuous. Six outer labial setae (2–3 µm) and four cephalic setae (4–6 µm) in single circle observed in the holotype and two paratype males (ICHUM 5869 and 5871), but inconspicuous in the other individuals including SEM specimen (Fig. 2A, B). Amphids not observed. Buccal cavity (Fig. 1G) divided into two sections: cheilostome—cup-shaped, with a circle of twelve tooth-like rugae; and esophastome—conical in shape, with a large dorsal onchium, two smaller ventrosublateral onchia, and four minute ventrosublateral teeth (Fig. 1G, H). Denticles absent. Pharynx (Fig. 1A, G) anteriorly surrounding esophastome, without posterior terminal bulb. Excretory pore and nerve ring indistinct. Ventral gland cell (Fig. 1A) located posterior to base of pharynx, posterior edge of gland at 1.5 times pharyngeal length from anterior body end. Testis (Fig. 1A) single, outstretched, beginning at anterior 20–25% of body length, located on right-hand side of intestine, posterior junction of vas deferens inconspicuous (complete testis observed only in the holotype and paratype ICHUM 5869, probably because of damage caused by freezing). Spicules (Fig. 3B, C) equal, arcuate, without capitulum, gradually tapering distally and 1.3–1.6 abd or 30–40% of tail length. Gubernaculum (Fig. 3C) well-developed: dorsal piece thin, almost straight and parallel to spicules; lateral pieces paired, L-shaped and bending at an obtuse angle, with one or two minute denticles at distal end; whole length (from proximal end of dorsal piece to distal end of lateral piece) 50–55% of spicule length. Precloacal supplement or cuticular elevation absent. A longitudinal row of cuticular wrinkles (Figs 3B, 4E) present at both subventral sides of precloacal region in all males, however it possibly artefact of preservation in ethanol and/or freezing. One or two short ventral setae just anterior to cloaca either present or absent. Tail (Fig. 3B) conico-cylindrical, 3.9–6.0 abd long, without ventral cuticular elevation. Three caudal glands just anterior to cloaca. Distinct spinneret at tip of tail. Females. Body (Fig. 3D) similar to males but thicker (mbd approximately 100–120 µm). Cephalic diameter 20– 25% of mbd. In one specimen (ICHUM 5877), ventral gland cell reaches 1.9 times pharyngeal length from anterior body end. Female reproductive system didelphic and amphidelphic. Ovaries opposed and reflexed: anterior ovary beginning at 15–30% of body length, located on right-hand side of intestine; posterior ovary ending at 70% of body length, located on leπ-hand side of intestine. Eggs oval, 3–18 in uteri, 30–60 µm in diameter. Vulva situated slightly anterior to middle of body. Tail 6.1–8.4 abd long, longer and thinner than in males. Three caudal glands situated in anal region, one or two of them located preanally, and the others located postanally. Etymology. The specific name antarcticum (Antarctic) is a Latin adjective taken from the type locality. Remarks. Graphonema antarcticum sp. nov. is most similar to G. metuliferum described from Japan in respect of the longer spicules (approximately 1.5 abd), the shape of the gubernaculum (whole length approximately 1/2 of spicule length, and with L-shaped lateral pieces bending at an obtuse angle and equipped with minute denticles at the distal end), and tail length in both sexes (approximately 4–6 abd in males and 6–9 abd in females). However, G. antarcticum sp. nov. differs from G. metuliferum by larger body size (L=2.0– 2.5 mm in males, 2.2–2.7 mm in females of G. antarcticum sp. nov. vs. 1.0– 1.4 mm in males, 1.2–1.4 mm in females of G. metuliferum) and the presence of the lateral differentiation (absent in G. metuliferum) (Fig. 4 H–J). The presence or absence of lateral differentiation is a good diagnostic character used to distinguish species or genera in Chromadoridae (cf. Tchesunov 2014). The genus Graphonema contains five species reported to have lateral differentiation, viz., G. arcticum, G. northumbriae G. parafricanum, G. scampae, and G. antarcticum sp. nov., and only one species, G. metuliferum, reported to have no lateral differentiation (Filipjev 1946; Gerlach 1958; Coles 1965; Warwick and Coles 1975; Kito 1981). It is unknown that lateral differentiation is present or absent in the other four known species. In addition, following minor differences are found from the original description by Kito (1981) and our observation of the type series of G. metuliferum, but these may not be enough for the diagnostic characters: amphideal fovea (indistinct in G. antarcticum sp. nov. vs. distinct in G. metuliferum), ventral gland cell (rounded in G. antarcticum sp. nov. vs. elongated in G. metuliferum), and longitudinal rows of cuticular wrinkles in precloacal region (present in G. antarcticum sp. nov. vs. absent in G. metuliferum).The distinctions between the new species and all known congeners are shown in the following key.Published as part of Shimada, Daisuke, Tsujimoto, Megumu & Watanabe, Kentaro, 2019, A New Free-living Marine Nematode Species of the Genus Graphonema (Nematoda: Chromadorida: Chromadoridae) from Antarctica, pp. 61-67 in Species Diversity 24 (1) on pages 63-66, DOI: 10.12782/specdiv.24.61, http://zenodo.org/record/458521
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Alterations in the mitochondrial proteome of neuroblastoma cells 2 in response to complex 1 inhibition
Get PDFIncreasing evidence points to mitochondrial dysfunction in Parkinson's disease (PD) associated with complex I dysfunction, but the exact pathways which lead to cell death have not been resolved. 2D-gel electrophoresis profiles of isolated mitochondria from neuroblastoma cells treated with subcytotoxic concentrations of l-methyl-4-phenyl-l,2,3,6-tetrahydropyridine (MPTP), a well-characterized complex I inhibitor, were assessed to identify associated targets. Up to 27 differentially expressed proteins were observed, of which 16 were identified using peptide mass fingerprinting. Changes in protein levels were validated by immunoprobing ID blots, confirming increases in heat shock cognate 71 kDa (Hsc70), 60 kDa heat shock protein (Hsp60), fumarase, glutamate oxaloacetate transaminase 2, ATP synthase subunit d, and voltage-dependent anion-channel 1 (VDACl). Immunoprobing of 2D blots revealed isoform changes in Hsc70, Hsp60, and VDACl. Subcytoxic concentrations of MPTP modulated a host of mitochondrial proteins including chaperones, metabolic enzymes, oxidative phosphorylation-related proteins, an inner mitochondrial protein (mitofilin), and an outer mitochondrial membrane protein (VDACl). Early changes in chaperones suggest a regulated link between complex 1 inhibition and protein folding. VDACl, a multifunctional protein, may have a key role in signaling between mitochondria and the rest of the cell prior to cell death. Our work provides new important information of relevance to PD
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