1,930 research outputs found
Application of fluorescent substance to the analysis of growth performance in Antarctic bivalve, Laternula elliptica
The shells of the Antarctic bivalve, Laternula elliptica, contain considerable information about their growth history and environmental changes. Growth rate determination in Laternula elliptica was attempted using a fluorescent substance, tetracycline, as a growth marker. The specimens were exposed to tetracycline solution of 200mg/ι for periods of 18 to 30h at about 0-2℃ without food. A distinct and narrow yellow fluorescent line was identified from the umbonal part to the ventral margin in all animals examined. This is the first success of fluorescent substance marking under the condition of low temperature and in Antarctic species. In the umbonal region, especially in the chondrophore, relatively rapid growth was observed. In the central part, a lower growth rate was observed. The growth rate of this species is not necessarily low in comparison with the temporal or tropical species. The combination of fluorescent marker and growth increment analyses will provide a powerful tool in estimating the benthic animal production, which is important information to understand the Antarctic ecosystem
HI-selected Galaxies as a probe of Quasar Absorption Systems
We investigate the properties of HI-rich galaxies detected in blind radio
surveys within the hierarchical structure formation scenario using a
semi-analytic model of galaxy formation. By drawing a detailed comparison
between the properties of HI-selected galaxies and HI absorption systems, we
argue a link between the local galaxy population and quasar absorption systems,
particularly for Damped Ly-alpha absorption (DLA) systems and sub-DLA systems.
First, we evaluate how many HI-selected galaxies exhibit HI column densities as
high as those of DLA systems. We find that HI-selected galaxies with HI masses
M(HI) > 10^8 solar masses have gaseous disks that produce HI column densities
comparable to those of DLA systems. We conclude that DLA galaxies where the HI
column densities are as high as those of DLA systems, contribute significantly
to the population of HI-selected galaxies at M(HI) > 10^8 solar masses. Second,
we find that star formation rates (SFRs) correlate tightly with HI masses
rather than B- (and J-) band luminosities.
In the low-mass range M(HI) < 10^8 solar masses, sub-DLA galaxies replace DLA
galaxies as the dominant population. The number fraction of sub-DLA galaxies
relative to galaxies reaches 40%-60% at HI masses 10^8 solar masses and 30%-80%
at 10^7 solar masses. The HI-selected galaxies at 10^7 solar masses are a
strong probe of sub-DLA systems that place stringent constraints on galaxy
formation and evolution.Comment: 25 pages, 13 figures, Accepted for publication in the Astrophysical
Journa
Tariff Elimination versus Tax Avoidance: Free Trade Agreements and Transfer Pricing
This study explores the new roles of rules of origin (ROO) when multinational enterprises (MNEs) manipulate their transfer prices to avoid a high corporate tax. ROO of a free
trade agreement (FTA) require exporters to identify the origin of exports to be eligible for
a preferential tariff rate. The results suggest that a value-added criterion of ROO restricts
MNEs’ abusive transfer pricing. Interestingly, an FTA with ROO can induce MNEs to shift
profits from a low-tax country to a high-tax country. Because ROO augment tax revenues
inside FTA countries, they can transform a welfare-reducing FTA into a welfare-improving
FTA
Application of a simplified probe feed impedance formula to the design of a dual frequency patch antenna
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