92 research outputs found

    History of exotic Meson (4-quark) and Baryon (5-quark) States

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    I briefly review the history of exotic meson (4-quark) and baryon (5-quark) states, which is rooted in the formalism of Regge pole and duality. There are robust model-independent predictions for the exchange of 4-quark (Baryonium) Regge trajectories in several processes, which are strongly supported by experiment. On the other hand the predictions for the spectroscopy of 4-quark resonances are based on specific QCD inspired models, with some experimental support. The corresponding predictions for the recently discovered exotic baryon (Pentaquark) state are briefly discussed.Comment: 14 pages Latex including 4 eps figures, final version to appear as a topical review in J. Phys.

    Neodymium isotope constraints on provenance, dispersal, and climate-driven supply of Zambezi sediments along the Mozambique Margin during the past ∌45,000 years

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    Marine sediments deposited off the Zambezi River that drains a considerable part of the southeast African continent provide continuous records of the continental climatic and environmental conditions. Here we present time series of neodymium (Nd) isotope signatures of the detrital sediment fraction during the past ~45,000 years, to reconstruct climate-driven changes in the provenance of clays deposited along the Mozambique Margin. Coherent with the surface current regime, the Nd isotope distribution in surface sediments reveals mixing of the alongshore flowing Zambezi suspension load with sediments supplied by smaller rivers located further north. To reconstruct past changes in sediment provenances, Nd isotope signatures of clays that are not significantly fractionated during weathering processes have been obtained from core 64PE304-80, which was recovered just north of the Zambezi mouth at 1329 m water depth. Distinctly unradiogenic clay signatures (ENd values <214.2) are found during the Last Glacial Maximum, Heinrich Stadial 1, and Younger Dryas. In contrast, the Nd isotope record shows higher, more radiogenic isotope signatures during Marine Isotope Stage 3 and between ~15 and ~5 ka BP, the latter coinciding with the timing of the northern hemisphere African Humid Period. The clay-sized sediment fraction with the least radiogenic Nd isotope signatures was deposited during the Holocene, when the adjacent Mozambique Shelf became completely flooded. In general, the contribution of the distinctly unradiogenic Zambezi suspension load has followed the intensity of precession-forced monsoonal precipitation and enhanced during periods of increased southern hemisphere insolation and high-latitude northern hemispheric climate variability

    Biochemical Study of the Population Heterogeneity and Distribution of the Oval Squid Sepioteuthis Lessoniana Complex in Southwestern Japan

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    Volume: 12Start Page: 129End Page: 13

    Alternative Male Mating Behaviors Dependent on Relative Body Size in Captive Oval Squid Sepioteuthis lessoniana (Cephalopoda, Loliginidae)

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    We observed the reproductive behavior of the oval squid Sepioteuthis lessoniana in captivity. The male used three different mating behaviors: male-parallel (MP), male-upturned (MU) and sneaking. Male competition over females frequently occurred before and during the female egg-laying period, and the outcome of most fights depended on male body size. Larger males guarded their partners from other males and performed MP mating during the egg-laying period of the paired females. In contrast, there was no pairing and mate guarding in MU mating and sneaking, which were adopted by smaller subordinate males as alternative tactics outside female egg-laying period and during the period, respectively. MP matings were 95% successful, but more than half of MU matings were unsuccessful. Higher mating success in MP mating was achieved through pairing, whereas males in MU mating were less successful because mating attempts without pair formation were often foiled by escape of the female. Sneaking was successful in all cases but occurred less frequently. Spermatophores were attached at the opening of the oviduct in MP mating, whereas they were attached around the female buccal membrane in MU mating and sneaking. Considering the route of egg transportation, higher fertilization success can be expected in MP mating because of the advantageous location of the attached spermatophores. Our results suggest that MP mating is used by larger, paired males during the female egg-laying period, and that MU mating and sneaking are alternative tactics adopted by smaller, subordinate males. These alternative mating behaviors would be conditional strategy dependent on relative body size, because some individual males displayed both MP and MU mating behaviors

    Numerical simulation of ground-water withdrawals in the southern Lihue Basin, Kauai, Hawaii /

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    Shipping list no.: 2002-0118-P.Includes bibliographical references (p. 42-43).Mode of access: Internet
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