Conversion of working memory to motor sequence in the monkey premotor cortex     

Ohbayashi M  Ohki K  Miyashita Y 《Science (New York, N.Y.)》2003,301(5630):233-236

To plan a serial order behavior, we hold serial sensory information in our minds and convert it to a movement program. We trained monkeys to memorize a sequence of positional cues and to reproduce it by making saccades in either the original or reverse order. The order was determined in the middle of a trial on the basis of an instruction stimulus. Triggered by the instruction stimulus, single neurons in the dorsal premotor cortex became transiently active only when the order needed to be determined. These transient neurons, together with nearby sustained neurons that hold information on cue or movement sequences, appear to mediate the generation of a motor program from the maintained information.  相似文献   

Attention but not awareness modulates the BOLD signal in the human V1 during binocular suppression     

Watanabe M  Cheng K  Murayama Y  Ueno K  Asamizuya T  Tanaka K  Logothetis N 《Science (New York, N.Y.)》2011,334(6057):829-831

Although recent psychophysical studies indicate that visual awareness and top-down attention are two distinct processes, it is not clear how they are neurally dissociated in the visual system. Using a two-by-two factorial functional magnetic resonance imaging design with binocular suppression, we found that the visibility or invisibility of a visual target led to only nonsignificant blood oxygenation level-dependent (BOLD) effects in the human primary visual cortex (V1). Directing attention toward and away from the target had much larger and robust effects across all study participants. The difference in the lower-level limit of BOLD activation between attention and awareness illustrates dissociated neural correlates of the two processes. Our results agree with previously reported V1 BOLD effects on attention, while they invite a reconsideration of the functional role of V1 in visual awareness.  相似文献   

<Emphasis Type="Italic">Myxobolus nagaraensis</Emphasis> n. sp. (Myxozoa: Myxosporea) causes abdominal distension of freshwater goby <Emphasis Type="Italic">Rhinogobius</Emphasis> sp. OR type from the Nagara River     

Hiroshi Yokoyama  Tetsushi Kageyama  Kenichi Ohara  Tetsuya Yanagida 《Fisheries Science》2007,73(3):633-639

ABSTRACT:   A new myxosporean parasite was found in the body cavity and caudal peduncle of the freshwater goby Rhinogobius sp. Orange type (OR) collected from the Nagara River, Gifu Prefecture, Japan. Infected fish exhibited substantial swelling of the abdomen caused by large parasitic cysts approximately 10 mm in size, formed in the visceral cavity. The cyst was a compacted aggregate of several smaller cysts, similar to a bunch of grapes in appearance. Histological examination showed that plasmodia developed within the renal capsule, and finally occupied the visceral cavity. Spores were ovoid with an attenuated anterior end. Sutural ridges were conspicuous with several folds on the edge. Average spore size was 11.9 (10.5–13.5) μm long, 9.0 (8.0–10.0) μm wide, and 6.5 (6.0–7.0) μm thick. Two equal polar capsules were 5.5 (4.5–6 0) μm long and 3.0 (2.5–4.0) μm wide. Partial small subunit ribosomal DNA sequences of the myxosporean were distinct from those of other myxozoan species in GENBANK. A new species name, Myxobolus nagaraensis , is proposed for this parasite.  相似文献   

Testes maturation of reared Pacific bluefin tuna Thunnus orientalis at two-plus years old     

Yoshifumi Sawada  Manabu Seoka  Keitaro Kato  Toshihiro Tamura  Masahiro Nakatani  Shoji Hayashi  Tokihiko Okada  Kenichi Tose  Shigeru Miyashita  Osamu Murata  Hidemi Kumai 《Fisheries Science》2007,73(5):1070-1077

ABSTRACT:   Stable reproduction is essential for supplying artificially hatched fish to tuna aquaculture. We observed testes maturation in reared Pacific bluefin tuna (PBT) Thunnus orientalis at 2+ years of age. The incidence of males with mature testes was 25.0%, and 40% of the males had developing testes that contain spermatozoa, while oocytes of the same aged females were not mature. These fish were wild-caught at 0+ years old in August 1997 and the gonads were examined in October 1998 and January–February 2000. Therefore, the age at examination in 2000 was estimated to be 2 years and 7–10 months old considering the spawning season of the wild PBT and the size when captured. Histological examination of the matured and developing testes showed that they contained spermatozoa, spermatids, spermatocytes, and spermatogonia. All the spermatozoa were observed to be motile in sea water under light microscopy. From the results of this and previous studies, matured males are probably fertile for at least 5 months a year in Kushimoto. The testes maturation observed at young age in captivity is considered promising to reduce the cost of broodstock maintenance for the juvenile production of PBT, especially if the sperm are cryopreserved.  相似文献   

Characterization of novel microsatellite DNA markers in ayu Plecoglossus altivelis     

Motoyuki Hara  Takashi Sakamoto  Masashi Sekino  Kenichi Ohara  Hironori Matsuda  Masahiro Kobayashi  Nobuhiko Taniguchi 《Fisheries Science》2006,72(1):208-210

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Effects of the feeding sequence of concentrate and forage and the feeding ratio of sake cake to grass hay on the characteristics and the entrapment effect of the ruminal mat in non‐lactating dairy cows     

Kenichi Izumi 《Animal Science Journal》2013,84(7):543-550

The effects of the feeding sequence of concentrate and forage, and of the feeding ratio of sake cake (SC) to grass hay (GH) on the ruminal mat characteristics and the entrapment effect for steamed flaked corn (SFC) by the mat were evaluated. Three non‐lactating, rumen‐cannulated Holstein cows were offered SC and GH using a ratio of 35:65 (SC35) or 65:35 (SC65). For SC35, SFC was fed at 1 h after or immediately before offering SC and GH, while for SC65, SFC was only fed at 1 h after. To estimate the degree of SFC entrapment in the ruminal mat, the location of SFC in the rumen and two types of mean retention time (MRT) were measured, that is, MRT for the SFC marker placed directly on the mat or taken orally. The ruminal mat was formed even when SC65 diet was consumed. The entrapment effect was not affected by the feeding sequence or the ratio. However, a more interesting finding is that the entrapment effect of the ruminal mat may not be as absolute as previously considered because of the large amount of SFC particles which precipitated at the bottom of the rumen 1 h after feeding.  相似文献   

Novel aspects of hydrophobins in wheat isolate of Magnaporthe oryzae: Mpg1, but not Mhp1, is essential for adhesion and pathogenicity     

Kanako Inoue  Harumasa Kitaoka  Pyoyun Park  Kenichi Ikeda 《Journal of General Plant Pathology》2016,82(1):18-28

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Identification and pathogenicity of Pythium species causing damping-off of kidney bean     

Yurika Matoba  Norio Kondo  Seishi Akino  Fujio Kodama  Shigeo Naito  Shigehiko Ebe 《Journal of General Plant Pathology》2008,74(1):81-85

Five Pythium species (Pythium irregulare, P. mamillatum, P. myriotylum, P. spinosum and P. ultimum var. ultimum) were isolated from the hypocotyls and roots of kidney bean plants with damping-off from a commercial field and from experimental plots that have undergone either continuous cropping with kidney bean or rotational cropping with arable crops. In inoculation tests, all five Pythium species were pathogenic to kidney bean. This is the first report of damping-off of kidney bean caused by Pythium species; we named this disease damping-off of kidney bean. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB291811, AB291944 and AB291945.  相似文献   

Taxonomic re-examination of several Japanese Stemphylium strains based on morphological and molecular phylogenetic analyses     

Daisuke Kurose  Tomoo Misawa  Takahito Suzui  Kazunori Ichikawa  Gan Kisaki  Long H. Hoang  Naruto Furuya  Kenichi Tsuchiya  Seiya Tsushima  Toyozo Sato 《Journal of General Plant Pathology》2015,81(5):358-367

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Development and validation of DNA markers linked to Sdvy-1, a common bean gene conferring resistance to the yellowing strain of Soybean dwarf virus     

Yoko Yamashita  Toru Takeuchi  Masataka Okuyama  Jun Sasaki  Kakumasa Onodera  Mikako Sato  Chihiro Souma  Shigehiko Ebe 《Breeding Science》2014,64(4):404-408

The yellowing strain of Soybean dwarf virus (SbDV-YS) causes yellowing and yield loss in common bean (Phaseolus vulgaris). The most effective control is achieved through breeding for resistance. An indeterminate climbing cultivar with a white seed coat, ‘Oofuku’, is resistant to SbDV-YS in inoculation tests. We crossed ‘Oofuku’ with an elite cultivar, ‘Taisho-Kintoki’, which is SbDV-YS-susceptible, determinate dwarf with a red-purple seed coat, and performed amplified-fragment-length polymorphism analysis of F₃ lines. From nucleotide sequences of the resistant-specific fragments and their flanking regions, we developed five DNA markers, of which DV86, DV386, and DV398 were closely linked to Sdvy-1, a resistance gene. Using the markers, we developed ‘Toiku-B79’ and ‘Toiku-B80’, the near-isogenic lines (NILs) incorporating Sdvy-1 in the background of ‘Taisho-Kintoki’. The NILs had similar growth habit, maturity date and seed shape to those of ‘Taisho-Kintoki’. The quality of boiled beans was also similar, except that the NILs had more seed coat cracking than ‘Taisho-Kintoki’. The NILs showed no SbDV-YS infection in inoculation tests. We suggest that Sdvy-1 is a useful source of SbDV-YS resistance in common bean.  相似文献