Breeding system and floral visitors of Veratrum album subsp. oxysepalum (Melanthiaceae)

Veratrum album subsp. oxysepalum is an andromonoecious perennial woodland herb. In the present study, to clarify the essential life-history characteristics of this species, sexual reproduction was examined and breeding experiments were carried out along with observations of floral visitors in the field. The results of the breeding experiments showed that this species has a high level of self-incompatibility. As various Coleoptera and Diptera visited the flowers, the seed production of V. album subsp. oxysepalum possibly depends on outcrossing pollination by insects.     

Prey use by web-building spiders: stable isotope analyses of trophic flow at a forest-stream ecotone

A forest-stream trophic link was examined by stable carbon isotope analyses which evaluated the relationship of aquatic insects emerging from a stream to the diets of web-building spiders. Spiders, aquatic and terrestrial prey, and basal resources of forest and stream food webs were collected in a deciduous forest along a Japanese headwater stream during May and July 2001. The ¹³C analyses suggested that riparian tetragnathid spiders relied on aquatic insects and that the monthly variation of such dependence is partly associated with the seasonal dynamics of aquatic insect abundance in the riparian forest. Similarly, linyphiid spiders in the riparian forest exhibited ¹³C values similar to aquatic prey in May. However, their ¹³C values were close to terrestrial prey in both riparian and upland (150m away from the stream) forests during June to July, suggesting the seasonal incorporation of stream-derived carbon into their tissue. In contrast, araneid spiders relied on terrestrial prey in both riparian and upland forests throughout the study period. These isotopic results were consistent with a previous study that reported seasonal variation in the aquatic prey contribution to total web contents for each spider group in this forest, implying that spiders assimilate trapped prey and that aquatic insect flux indeed contributes to the energetics of riparian tetragnathid and linyphiid spiders.     

DISCOVERY OF THE OLIGO-MIOCENE RODENTS FROM WEST JAPAN AND THEIR GEOLOGICAL AND PALEONTOLOGICAL SIGNIFICANCE

IutroduCtionTertiaryrodentfossilshavebeenrarelyfoundinJapan.TomidaandSetoguchi(l994)reportedninesPecimensfromtheEarlyMiocenesedimentsintheMisunamiandKhnibasins,GifuPrefecture,centralJapanwithabridreviewoftheTertiaryrodentsfromtheJapaneseIslands.Accordingtotheirreport,therodentfaunainthesebasinsiscomposedofthesPechoensreferredtoCastoridae,Eomyidaeandunidentifiedrodents.Amongthem,CastoridaeincludesYoungoNersinensis,acharacteristicChineseMiocenebeaver.TheoccurrenceofYoungofthersinensiss…     

Effects of blood flow to the prefrontal cortex on high-intensity exercise combined with high-decibel music

We studied the effects of high-intensity exercise (70-75% of VO₂ max) combined with high-decibel music (100 dB) on cognitive function (measured by the Stroop test) and related blood flow changes to the prefrontal cortex (measured by Oxy-hemoglobin (Hb), Deoxy-Hb, tissue oxygen index (TOI), and normalized tissue hemoglobin index (nTHI)). The subjects of the study were 28 healthy female university students in their early 20s. Subjects were categorized into control group (CG), music group (MG), exercise group (Ex), and music and exercise group (MnEx). A crossover design was implemented so that all subjects participated in all test groups. We found no significant difference in reaction time between CG and MG for the neutral and incongruent tasks of Stroop test. However, there were significant improvements in the neutral and incongruent tasks for both the Ex (p < 0.01) and MnEx (p < 0.01) groups. Oxy-Hb measurements in the prefrontal cortex of the brain supported the Stroop test data. We found no difference between Ex and MnEx in the TOI; however, there was a significant decrease (p < 0.05) in MnEx compared to Ex. In addition, Ex resulted in a significant increase (p < 0.05) in nTHI as compared to CG. These results indicate that high decibel music could negatively affect prefrontal cortex activation of the brain during exercise.     

CHANGES OF CHROMOSOMES DURING THE EARLY NEURAL DEVELOPMENT OF A JAPANESE NEWT, CYNOPS PYRRHOGASTER

The karyotype of Cynops pyrrhogaster was determined on the mitotic chromosomes in the presumptive neural area of an early gastrula. 24 chromosomes of a diploid set consisted of 8 metacentric and 4 submetacentric pairs. Individual chromosomes were identified on the basis of their morphology and characteristic C-binding patterns. Sex chromosomes were not identified. Total length of the haploid chromosome set in the presumptive neural area decreased remarkably from morulae to gastrulae, further continued to decrease up to neurulae and thereafter remained unchanged till tail-buds. Chromosome shortening occurring from morulae to gastrulae was accompanied with a prominent decrease in chromosome volume, keeping chromosome width constant. Shortening took place evenly along the longitudinal axis of a chromosome. When gastrulae and neurulae were compared concerning their positions of the appearance of the C-bands, the basic pattern remained unchanged. In certain chromosomes, the number of C-bands decreased as the result of their fusion, as gastrulae proceeded to neurulae.     

A Monoclonal Antibody that Binds Preferentially to Human Suppressor T Cells

A monoclonal antibody termed JM3-3-3A was produced by somatic cell hybridization. The reactivity was assessed by indirect immunofluorescence. JM3-3-3A was reactive with 41% human peripheral blood T cells and 48% non-T cells. Among various human lymphoblastoid cell lines (MOLT 4F, JM, and TALL-I), TALL-I was found not to be reactive with JM-13-3-3A. Human peripheral blood Tcells fractionated by JM3-3-3A-coated dish panning were submitted to functional studies. JM3-3-3A positive T cells responded to mitogens, concanavalin A and phytohemagglutinin-P much better than JM3-3-3A negative T cells in the presence or absence of adherent cells. JM3-3-3A positive T cells showed suppressor activity and JM3-3-3A negative T cells showed helper activity in pokeweed mitogen-induced Ig production. More than fifty percent of the JM3-3-3A positive T cells were reactive with OKT8 which binds to suppressor/ cytotoxic T cells, whereas 18% of JM3-3-3A negative T cells were reactive with OKTIl. In addition, immunoprecipitation experiments identified a protein with an approximate molecular weight of 43,000 as a cell surface antigen for JM3-3-3A. Thus, the reactivity of JM3-3-3A showed a wide distribution but human peripheral blood T cells could be dissected functionally by this antibody.     

Karyology of plant species endemic to Ullung Island (Korea) and selected relatives in peninsular Korea and Japan

Chromosomal changes, including polyploidy and dysploidy, often accompany speciation of angiosperms in continental regions. In contrast, on geologically young oceanic islands, little change in chromosome number occurs during speciation of endemics. Absence of change in number of chromosomes does not necessarily mean lack of chromosomal rearrangements. To determine whether detailed karyotypic changes accompany speciation in island habitats, nine endemic species in Abelia , Acer , Campanula , Dystaenia , Hepatica , Rubus , Valeriana , Veronica and Viola of Ullung Island, a geologically young volcanic island off the coast of peninsular Korea in the Eastern Sea, have been compared with progenitors in mainland Korea and Japan. Results confirm that no changes in ploidy level or dysploidy have occurred during speciation of these endemic island taxa. Detailed karyotypic analysis indicates that most of the taxa have not undergone significant macromorphological chromosomal changes. In the bitypic genus Dystaenia (Umbelliferae), D. takesimana , endemic to Ullung Island, differs karyotypically from its progenitor, D. ibukiensis from Japan, in a number of chromosomal elements, some of which appear to be satellites and others of which may represent B chromosomes. This suggests that rDNA loci might have been lost or rearranged during speciation. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 138 , 93–105.