113,405 research outputs found
Impeded inverse energy transfer in the Charney--Hasegawa--Mima model of quasi-geostrophic flows
No full textThe behaviour of turbulent flows within the single-layer quasi-geostrophic (Charney-Hasegawa-Mima) model is shown to be strongly dependent on the Rossby deformation wavenumber lambda (or free-surface elasticity). Herein, we derive a bound oil the inverse energy transfer, specifically on the growth rate dl/dt of the characteristic length scale e representing the energy centroid. It is found that dl/dt = l(s) >> lambda(-1)) the inverse energy transfer is strongly impeded, in the sense that under the usual time scale no significant transfer of energy to larger scales occurs. The physical implication is that the elasticity of the free surface impedes turbulent energy transfer in wavenumber space, effectively rendering large-scale vortices long-lived and inactive. Results from numerical simulations of forced-dissipative turbulence confirm this prediction.Peer reviewe
The Silly Jelly - Fish - T. Hasegawa version
No full text"The Dragon King sent a jellyfish to Monkeyland to get a monkey whose liver could be used to cure the young Dragon Queen's illness. Read to find out how the monkey tricked the jellyfish, and why jellyfish have no bones today.(The International Children's Digital Library, http://www.childrenslibrary.org/icdl/BookPreview?bookid=chathes_00361330&route=text&lang=null&msg=&ilang=English
Phlorest phylogeny derived from Lee & Hasegawa 2013 'Evolution of the Ainu Language in Space and Time'
No full text<p>Cite the source of the dataset as:</p>
<blockquote>
<p>Lee S, Hasegawa T (2013) Evolution of the Ainu Language in Space and Time. PLoS ONE 8(4): e62243. doi: 10.1371/journal.pone.0062243</p>
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Trichuris mallomyos Hasegawa & Dewi, 2017, sp. nov.
No full textTrichuris mallomyos sp. nov. (Figs. 13–22) General. Usual size as a Trichuris in murids. Cuticle with fine transversal striation. Anterior part of body narrow, thread-like, tapering to cephalic end; posterior part of body stout (Figs. 13, 19). Minute cephalic stylet present. Stichosome with 1 row of stichocytes, and 1 pair of conspicuous cells at esophago-intestinal junction level (Figs. 13, 19). Nucleus of stichosome present per 4 to 5 subdivisions, in middle portion (Fig. 14). Bacillary band commencing just after cephalic end, well developed in middle portion of anterior body (Figs. 14, 15), becoming narrower and invisible anterior to esophago-intestinal junction. Round cuticular inflations of various sizes bordering bacillary band present in anterior portion of body. Male (10 specimens): Length 28.8 (24.6–32.4) mm. Anterior portion of body 18.7 (15.3–21.0) mm long, corresponding to 65 (62–68) % of body length. Width at middle of anterior body 101 (95–111), esophago-intestinal junction 227 (202–259) and thick portion of posterior body 359 (331–397). Round cuticular inflations present in area from 258–370 to 1287–1990 from anterior end. Stichosome with ca. 180–200 nuclei. Testis recurved posterior to esophago-intestinal junction, directed posteriorly forming convolutions, ending near anterior end of proximal cloacal tube (Fig. 13). Proximal cloacal tube stout, 2.53 (2.25–2.77) mm long, united laterally to distal cloacal tube of 0.92 (0.75–1.37) mm long (Fig. 13). Spicular pouch 0.28 (0.09–0.73) mm long (Fig. 13). Spicule length 2.89 (2.75–3.13) mm long, corresponding to 10.1 (8.5–11.9) % of body length, sharply pointed distally (Figs. 16–18). Distal portion of spicule with pit-like structures on one side (Fig. 17). Spicular sheath densely spinose; distal end of fully extended spicular sheath devoid of spines, with reticulate markings (Fig. 18). Cloaca subterminal with 1 pair of simple papillae (Fig. 16). Female (10 specimens): Length 35.1 (28.1–41.4) mm. Anterior body 22.0 (17.2–27.1) mm long, corresponding to 62.6 (59.6–66.9) % of body length. Width at middle of anterior body 100 (86–109), esophagointestinal junction 243 (202–274) and thick portion of posterior body 420 (372–486). Round cuticular inflations present in area from 198–455 to 1505–2109 from anterior end. Stichosome with ca. 190–210 nuclei. Vulva slightly elevated, 81 (0–137) posterior to esophago-intestinal junction (Fig. 20). Vagina muscular, winding posteriorly, 1.37 (1.01–1.65) mm long (Fig. 21). Ovary extending to preanal level (Figs. 19, 21). Anus subterminal (Fig. 20). Eggs lemon-shaped, thick shelled, brownish, with polar plugs, 90.1 ± SD 2.9 (83–95) by 39.2 ± SD 1.2 (36–41) (n=50) (Fig. 22). Taxonomic summary. Type host: Mallomys rothschildi Thomas, 1898 (Rothschild’s woolly rat) (Hydromini: Murinae: Muridae). Site in host: Cecum. Type locality: Highland forest near Wamena (4˚11’S, 138˚58’E; 1500 m elevation), Papua Indonesia, Indonesia. Date of collection: 4 August 1993. Type specimens: USNM 1422105 (hototype male and allotype female), USNM 1422106 (6 male and 6 female paratypes), MZB Na 721 (3 male and 3 female paratypes). Coparasites: Odilia mallomyos Hasegawa & Syafruddin, 1994 (Nematoda: Heligmonellidae) (Hasegawa & Syafruddin, 1994). Symbiotypes: AMNH M-267742, M-267743. Etymology. Species epithet is derived from the generic name of the type host. Remarks. This species is also assigned to Trichuris for the same reasons as for the preceding species. By having a gradually tapered and sharply pointed spicule, it resembles T. musseri, T. petrowi and T. spalacis among those parasitic in murids (Petrov & Potekhina, 1953; Skrjabin et al., 1957). It is easily distinguished from T. musseri in that the body is much larger and the number of nuclei per divisions of stichosome is fewer. It also differs from the latter two species by the following features: T. petrowi has a cephalic expansion and a larger ratio of anterior body to worm length (>70 %) in male, and much longer distance (> 1 mm) between the anus and posterior end of body in female; T. spalacis has a smaller ratio of anterior body to worm length (<60 %) in both sexes and much smaller eggs (62–65 by 29 µm) (Petrov & Potekhina, 1953; Skrjabin et al., 1957). Morphology of the distal end of the spicule has not been described or figured in some Trichuris species in murids, namely, T. neotomae Chandler, 1945 and T. peromysci Chandler, 1946. Although their males have body length comparable to the present males (22–23 mm in T. neotomae and 14.7–31.8 mm in T. peromysci), they possess a much shorter spicule (1.15– 1.23 mm and 0.86–1.4 mm long, respectively), being readily distinguished from T. mallomyos sp. nov. (Chandler, 1945, 1946). Trichuris germani, an endemic congener parasitic in the endemic murids of Papua New Guinea, differs from the present species by having smaller eggs (42.5–63 by 25.5–27.7 µm) in addition to the rounded distal end of the spicule (Smales, 2013).Published as part of Hasegawa, Hideo & Dewi, Kartika, 2017, Two new species of Trichuris (Nematoda: Trichuridae) collected from endemic murines of Indonesia, pp. 127-135 in Zootaxa 4254 (1) on pages 130-132, DOI: 10.11646/zootaxa.4254.1.9, http://zenodo.org/record/54574
My Lord Bag - O'Rice - T. Hasegawa version
No full text"Once upon a time, there lived a brave warrior called "Tawara - no - Toda," or "My Lord Bag - o' - Rice." One day, when he was about to cross a bridge over a river flowing down from a lake, he saw a big serpent lying in his path. He calmly stepped on it to go on his way, and the serpent instantly changed into a tiny dwarf, who prostrated himself on the bridge, claimed that he dwelled on the bottom of the lake, and begged Tawara to avenge for him on the centipede living in the hills. Tawara agreed to do so on the spot, and the dwarf took him to his summer - house on the lake - bottom. While the dwarf was entertaining Tawara, the centipede over a mile long came creeping down from the hills. Tawara slew it with an arrow from his enormous bow. The dwarf rewarded him by giving him a large bronze bell, sword, suit of armour, roll of silk that never ran out no matter how much of it was used, and a bag of rice that never became empty. Tawara donated the bell to a temple and lived happily - and in opulence - ever after." (Kyoto University of Foreign Studies, https://www.kufs.ac.jp/toshokan/chirimenbon/b_15.html
Reply to comment by H. Hasegawa on "Evolution of Kelvin-Helmholtz activity on the dusk flank magnetopause"
No full textWe demonstrate, on experimental grounds, that the justifications for the comment by Hasegawa [2009], hereinafter
H09, on work done by Foullon et al. [2008], hereinafter F08, are not well founded
Kachi - Kachi Mountain - T. Hasegawa version
No full text"An old man captured a mischievous badger and hung it to a rafter by the feet. While the old man was away, the badger tricked his wife into undoing the cord, and then killed her. Later, as the old man lamented his wife's death, a hare came forward and offered to avenge the murder. The hare lured the badger out of his hole with parched beans, had it shoulder a bundle of dried - grass, and then set fire to the bundle. When the badger retired to its hole to nurse the burns, the hare applied a sticking plaster that he said would heal them but that actually contained red pepper. Afterward, inviting the badger to go fishing, the hare boarded a boat of wood, but tricked the badger into boarding one of clay. The clay boat gradually dissolved in the water, and the badger was drowned." (Kyoto University of Foreign Studies, https://www.kufs.ac.jp/toshokan/chirimenbon/b_05.html)1886 reprin
Trichuris musseri Hasegawa & Dewi, 2017, sp. nov.
No full textTrichuris musseri sp. nov. (Figs. 1–12) General. Small sized as a Trichuris in murids. Cuticle with fine transversal striation. Anterior part of body narrow, thread-like, tapering to cephalic end; gradually increasing to widest portion in posterior body and again slightly tapered to posterior end (Figs. 1, 2, 9). Minute cephalic stylet present. Stichosome with 1 row of stichocytes, and 1 pair of conspicuous cells at esophago-intestinal junction level (Figs. 2–5, 10). Nuclei of stichosome numerous, almost 1 nucleus per 1 to 2 subdivisions, in middle to posterior portions (Figs. 3–5). Bacillary band commencing just after cephalic end, well developed in middle portion of anterior body (Figs. 2–5), becoming narrower and invisible anterior to esophago-intestinal junction. Round cuticular inflations of various size bordering bacillary band present in anterior portion of body (Fig. 2). Male (9 specimens): Length 8.79 (7.89–9.24) mm. Anterior portion of body 5.32 (4.93–5.65) mm long, corresponding to 61 (58–63) % of body length. Width at middle of anterior body 57 (44–69), esophago-intestinal junction 129 (99–162) and thick portion of posterior body 182 (162–210). Round cuticular inflations present in area from 192–258 to 618–860 from anterior end. Stichosome with ca. 160 nuclei. Testis recurved posterior to esophago-intestinal junction, directed posteriorly forming convolutions, ending near anterior end of proximal cloacal tube (Fig. 1). Proximal cloacal tube stout, 0.66 (0.45–0.91) mm long, united laterally to distal cloacal tube of 0.53 (0.35–0.71) mm long (Fig. 1). Spicular pouch 0.18 (0.09–0.28) mm long (Fig. 1). Spicule slender, 1.11 (0.90–1.28) mm long, corresponding to 12.7 (10.0–14.1) % of body length, sharply pointed distally (Figs. 6-7). Distal portion of spicule with pit-like structures on one side (Fig. 7). Spicular sheath densely spinose (Figs. 6-7). Distal end of fully extended spicular sheath devoid of spines, with faint reticulate markings (Fig. 8). Cloaca subterminal with 1 pair of simple papillae (Fig. 6). Female (10 specimens): Length 10.9 (9.3–12.4) mm. Anterior body 6.20 (5.55–7.22) mm long, corresponding to 57.0 (54.6–59.6) % of body length. Width at middle of anterior body 58 (51–67), esophago-intestinal junction 135 (121–158) and thick portion of posterior body 202 (184–218). Round cuticular inflations present in area from 162–300 to 684–1039 from anterior end. Stichosome with ca. 160–170 nuclei. Vulva 40 (10–71) posterior to esophago-intestinal junction, with anterior lip of varying degree of development and minute posterior lip (Figs. 9, 10). Vagina muscular, winding posteriorly, 0.67 (0.56–0.78) mm long (Figs. 11, 12). Ovary extending to preanal level (Figs. 9, 11). Anus subterminal (Fig. 11). Eggs lemon-shaped, thick shelled, brownish, with polar plugs, 73.6 ± SD 1.7 (71–77) by 33.0 ± SD 1.4 (30–35) (n=25), with exception of one egg sized 91 by 38 (Fig. 12). Taxonomic summary Type host: Echiothrix centrosa Miller & Hollister, 1921 (large-bodied shrew rat) (Rattini: Murinae: Muridae). Site in host: Cecum. Type locality: Kuala Navusu (00˚58’S, 120˚27’E; 38–155 m elevation), Malakosa, Central Sulawesi, Indonesia. Date of collection: October 1975. Type specimens: USNM 1422103 (hototype male and allotype female), USNM 1422104 (5 male and 6 female paratypes), MZB Na 720 (3 male and 3 female paratypes). Coparasites: Musserakis sulawesiensis Hasegawa, Dewi & Asakawa, 2014 (Nematoda: Heterakidae) (Hasegawa et al., 2014). Symbiotypes: AMNH M-225678 – M-225681. Etymology. The species epithet is dedicated to Dr. G. G. Musser, an outstanding mammalogist, who has made invaluable contributions on the systematics of murid rodents of Indonesia. Remarks. By having a stichosome, tubular intestine, vulva positioned near esophago-intestinal junction, monodelphic reproductive system and eggs with polar plugs but without membranous envelope or polar filaments, the present species belongs to the family Trichuridae in the superfamily Trichinelloidea (Chabaud, 1974; Anderson & Bain, 1982). By possessing much thicker posterior portion of body, a bacillary band at esophageal portion, stichocytes similar in form and arranged in a single row and unembryonated eggs in the uterus, it belongs to the subfamily Trichurinae which includes only the genus Trichuris Roederer, 1761 (Anderson & Bain, 1982). By having a small body, the present species is readily distinguished from all congeners known from murids because all have average body length over 10 mm in males and 15 mm in females (cf. Skrjabin et al., 1957; Quentin, 1966; Bernard, 1969; Tenora, 1969; Johnson, 1973; Sadighian et al., 1974; Feliu et al., 2000; Robles, 2011; Ribas et al., 2013; Smales, 2013; Robles et al. 2014). The present species is characteristic by having a gradually-tapered and sharply pointed distal end of the spicule, being readily distinguished from most congeners parasitic in murids, which have dull or round distal end or suddenly narrowed near distal end of the spicule (cf. Quentin, 1966; Robles, 2011; Robles et al., 2014; Smales, 2013; Feliu et al., 2000; Ribas et al., 2013). Among the congeners parasitic in murids, only T. petrowi in Arvicola terrestris of Tatarstan, Russia, and T. spalacis in the mole rat, Spalacis microphthalmus, of Ukraine, have been known to have gradually tapered and pointed spicule (Petrov & Potekhina, 1953; Skrjabin et al., 1957). However, the former species has a cephalic expansion in the male and much longer distance (> 1 mm) between the anus and posterior end of body in female, and the latter species has a smaller ratio (<58 %) of anterior body to worm length in males and smaller eggs (62–65 by 29 µm), differing from the present species (Petrov & Potekhina, 1953; Skrjabin et al., 1957).Published as part of Hasegawa, Hideo & Dewi, Kartika, 2017, Two new species of Trichuris (Nematoda: Trichuridae) collected from endemic murines of Indonesia, pp. 127-135 in Zootaxa 4254 (1) on pages 128-129, DOI: 10.11646/zootaxa.4254.1.9, http://zenodo.org/record/54574
A user-friendly method for computing indenite integrals of oscillatory functions
No full textFor indenite integrals Q(f ; x , ω) =∫^x_-1 f(t)e^iωt dt (x∈［－1, 1]) Torii and the first author (Hasegawa and the first author (Hasegawa and Torii,1987) developed a quadrature method of Clenshaw-Curtis (C-C)type.Its improvement was made and combined with Sidi’s mW-transformation by Sidi and the first author (Hasegawa and Sidi, 1996) to compute infinite oscillatory integrals. The improved method per se, however, has not been elucidated in its attractive features, which here we reveal with new results and its detailed algorithm. A comparison with a method of C–C type for definite integrals Q(f ; x , ω) due to Domínguez et al.
(2011) suggests that a smaller number of computations is required in our method. This is achieved by exploiting recurrence and normalization relations and their associated linear system. We show their convergence and stability properties and give a verified truncation error bound for a result computed from the linear system with finite dimension. For f(z) analytic on and inside an ellipse in the complex plane z the error of the approximation to Q(f ; x , ω) of the improved method is shown to be bounded uniformly. Numerical examples illustrate the stability and performance of the method.journal articl
Statistical properties of Charney-Hasegawa-Mima zonal flows
No full textA theoretical interpretation of numerically generated probability density functions (PDFs) of intermittent plasma transport events in unforced zonal flows is provided within the Charney-Hasegawa-Mima (CHM) model. The governing equation is solved numerically with various prescribed density gradients that are designed to produce different configurations of parallel and anti-parallel streams. Long-lasting vortices form whose flow is governed by the zonal streams. It is found that the numerically generated PDFs can be matched with analytical predictions of PDFs based on the instanton method by removing the autocorrelations from the time series. In many instances the statistics generated by the CHM dynamics relaxes to Gaussian distributions for both the electrostatic and vorticity perturbations, whereas in areas with strong nonlinear interactions it is found that the PDFs are exponentially distributed
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