226 research outputs found
Taxonomy and identification of the armored dinoflagellate genus Heterocapsa (Peridiniales, Dinophyceae)
The armored dinoflagellate genus Heterocapsa is composed of relatively small species, including a species responsible for harmful red tides, H. circularisquama. Some Heterocapsa species such as H. rotundata and H. triquetra have been well documented as red tide-forming species, but are not recognized as causing harmful effects. Following sequential shellfish mass mortalities in the coastal waters of western Japan due to H. circularisquama red tides, this species has attracted considerable interest. Many properties of this species, such as its distribution and growth characteristics, have been investigated to better understand the mechanisms involved in harmful red tide formation. Related to the need for unambiguous identification of H. circularisquama, several unidentified (or undescribed) Heterocapsa species, which must be distinguished from the harmful taxon, have been detected sympatrically in regions where H. circularisquama blooms occur. However, the taxonomic affiliation of these Heterocapsa species have not yet been determined because several characteristics of Heterocapsa (e.g. body scale ultrastructure) have not yet been reported from all described species due to the changing taxonomic criteria. After the taxonomic ambiguities in this genus were resolved, cellular and body scale morphology of Heterocapsa were reinvestigated and several new species were described. In the present paper, the taxonomic history and morphological characters of the genus Heterocapsa are summarized
Mythic Narratives: The Chronicling of Conceptual Art
An exploration of the mythologized narratives that the work and lives of Conceptual artists Bas Jan Ader, Ana Mendieta, and Francis Alÿs have created and inspired. By virtue of their biographies, the fetishization of their personalities, and the ways in which this anecdotal information can be read in their work, mythologized narratives have been constructed, allowing for a prolonged interest existing within and without the confines of the art world. These mythologies come together as part of the oral tradition of the art world, a chronicling of narratives that incites continued interest for future generations
Phylogentic studies of the thermophilic cyanobacterium, Mastigocladus laminosus, inhabiting the hot springs of Japan and Myanmar
Variation of strong correlation effects in A-site ordered perovskites CaCu3Ti4-xRuxO12: Photoemission and inverse photoemission studies
We have systematically studied the strong correlation effects in A-site
ordered perovskites CaCu3Ti4-xRuxO12 (x = 0, 1, 3.5, 4) by using photoemission
and inverse photoemission spectroscopies. In x = 0, 1, 3.5, the peak positions
of the strongly correlated Cu 3d states around -3.8 eV and Ti 3d states around
3.6 eV little change. On the other hand, in x = 4, the Cu 3d states is observed
around -2.5 eV. These indicate that Ti plays an important role to retain the
strong correlation effects. In addition, the multiplet structures of Cu 3d
final states from -8 to -15 eV become weak as Ru increases, indicating the
reduction of the localized characters of Cu 3d states. At the Fermi level, we
observe the absence of spectral weight in x = 0, 1 and the development of Ru 4d
in-gap states between the Cu 3d and Ti 3d peaks in x = 3.5, 4, which give rise
to the metal-insulator transition between x = 1 and x = 3.5.Comment: 12 pages, 3 figure
Magnetic excitations in a new anisotropic Kagom\'{e} antiferromagnet
The Nd-langasite compound contains planes of magnetic Nd3+ ions on a lattice
topologically equivalent to a kagom\'{e} net. The magnetic susceptibility does
not reveal any signature of long-range ordering down to 2 K but rather a
correlated paramagnetism with significant antiferromagnetic interactions
between the Nd and a single-ion anisotropy due to crystal field effect.
Inelastic neutron scattering on Nd-langasite powder and single-crystal allowed
to probe its very peculiar low temperature dynamical magnetic correlations.
They present unusual dispersive features and are broadly localized in
wave-vector Q revealing a structure factor associated to characteristics short
range-correlations between the magnetic atoms. From comparison with theoretical
calculations, these results are interpreted as a possible experimental
observation of a spin liquid state in an anisotropic kagom\'{e}
antiferromagnet.Comment: to appear in Physica
Phytoplankton assemblage of the Merambong Shoal, Tebrau Straits with note on potentially harmful species
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