Search results for "Llum"
showing 10 items of 570 documents
The coralline red alga Lithophyllum kotschyanum f. affine as proxy of climate variability in the Yemen coast, Gulf of Aden (NW Indian Ocean)
2014
Abstract Recent investigations have shown the potential of red coralline algae as paleoclimatic archive. A previously unexplored subfamily of coralline algae, the Lithophylloideae, was investigated from the Gulf of Aden (Balhaf, Yemen). Seasonal changes in Mg/Ca, Li/Ca and Ba/Ca composition of Lithophyllum kotschyanum f. affine were investigated by Laser Ablation-Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). For the first time in coralline algae, the Li/Ca composition was analyzed and showed a highly significant and positive correlation with Mg/Ca and SST. Monthly algal Mg/Ca and Li/Ca variations indicate a positive correlation with sea surface temperature (SST), and sea surface…
Ultrastructure of Joenoides intermedia (Grassé 1952), a symbiotic parabasalid flagellate of Hodotermes mossambicus, and its comparison with other joe…
2003
Light and electron microscopy confirms the validity of the genus Joenoides. The cell is organised like other joeniids with a triangular flagellar area of about two thousand flagella/basal bodies and three privileged basal bodies located apart at the anterior corner of the flagellar area. Characteristically, the two parabasal fibres attached to the basal body #2 are very large and composed of striated subfibres that spread in the cytoplasm, where they sustain Golgi bodies. The flagellar area is surrounded by the axostylar capitulum, which is underlain by a thick layer of preaxostylar fibres, a very strongly amplified component in this species. The axostylar trunk is composed of a bundle of m…
Co-expression and Functional Interaction of Silicatein with Galectin
2006
Sponges (phylum Porifera) of the class of Demospongiae are stabilized by a siliceous skeleton. It is composed of silica needles (spicules), which provide the morphogenetic scaffold of these metazoans. In the center of the spicules there is an axial filament that consists predominantly of silicatein, an enzyme that catalyzes the synthesis of biosilica. By differential display of transcripts we identified additional proteins involved in silica formation. Two genes were isolated from the marine demosponge Suberites domuncula; one codes for a galectin and the other for a fibrillar collagen. The galectin forms aggregates to which silicatein molecules bind. The extent of the silicatein-mediated s…
Epitypification of Hagaea alsinifolia (Polyycarpon tetraphyllum subsp. Alsinifolium, Caryophyllaceae)
2018
As part of the ongoing studies on the genus Polycarpon Linnaeus (1759: 859, 881) (see e.g., Iamonico 2015a, 2015b, 2015c, Iamonico & Domina 2015), and on the Italian loci classici (see e.g., Peruzzi et al. 2015, Brundu et al. 2015, Domina et al. 2016, Di Gristina et al. 2017, Domina et al. 2017, 2018a, 2018b), we present here a note regarding Hagaea alsinifolia Bivona-Bernardi (1815: 7–8) [currently accepted (see Bartolucci et al. 2018) as Polycarpon tetraphyllum Linnaeus (1759: 881) subsp. alsinifolium (Biv.) Ball (1877: 370)].
Solubilization of an oligomycin-sensitive ATPase complex fromRhodospirillum rubrumchromatophores and its inhibition by various antibiotics
1978
Electromagnetic spectrum and color vision
2004
In most of occasions the maps, drawings and printed images are elaborated thinking that the observer will visualize them with illuminants like the light of the day. With these illuminants, for example the CIE D/sub 65/, we can distinguish the great quantity of colors that it is capable the human eye. But if the illuminant has a very different spectrum than the light of day, for example the light of acetylene, the number of colors that we are able to distinguish can decrease drastically.
<i>Fucus</i> and <i>Ascophyllum</i> seaweeds are significant contributors to coastal iodine e…
2012
Abstract. Based on the results of a pilot study in 2007, which found high mixing ratios of molecular iodine (I2) above the intertidal macroalgae (seaweed) beds at Mweenish Bay (Ireland), we extended the study to nine different locations in the vicinity of Mace Head Atmospheric Research Station on the west coast of Ireland during a field campaign in 2009. I2 mixing ratios from 104 to 393 ppt were found above the macroalgae beds, implying a high source strength of I2. Such mixing ratios are sufficient to result in photochemically-driven coastal new-particle formation events. Mixing ratios above the Ascophyllum nodosum and Fucus vesiculosus beds increased with exposure time – after 6 h exposur…
ChemInform Abstract: Two New Triterpene Saponins from Acanthophyllum laxiusculum
2015
Two new triterpene glycosides, 1 and 2, together with three known ones, were isolated from roots of Acanthophyllum laxiusculum Schiman-Czeika. The structures of the new compounds were established by extensive 1D- and 2D-NMR spectroscopic experiments and MS analyses as 23-O-β-D-galactopyranosylgypsogenic acid 28-O-{β-D-glucopyranosyl-(1→2)-6-O-[4-carboxy-3-hydroxy-3-methyl-1-oxobutyl]-β-D-glucopyranosyl-(1→6)}-[β-D-glucopyranosyl-(1→3)]-β-D-galactopyranosyl ester (1) and gypsogenic acid 28-O-{β-D-glucopyranosyl-(1→2)-6-O-[4-carboxy-3-hydroxy-3-methyl-1-oxobutyl]-β-D-glucopyranosyl-(1→6)}-[β-D-glucopyranosyl-(1→3)]-β-D-galactopyranosyl ester (2).
Transport-related amino acid metabolism in germinating barley grains
1987
When eight [14C]-labelled amino acids were separately injected into the endosperm of germinating (4 days at 20°C) barley (Hordeum vulgare L. cv. Himalaya) grains, the label was rapidly taken up by the scutellum and further transported to the shoot and roots. Some of the amino acids (leucine, lysine and asparagine) were transported in an intact form through the scutellum to the seedling, whilst glutamic acid and aspartic acid were largely converted to glutamine in the scutellum. Proline was mainly transported unchanged, but a small part of the label appeared in glutamine. Arginine was mostly broken down in the scutellum, possibly providing ammonia for the synthesis of glutamine. During furth…
Relationships Between Dimorphism, Cell Wall Structure, and Surface Activities in Candida albicans
1991
Most cells are covered with a complex network of interacting molecules that form the extracellular matrix. These molecules (proteins and polysaccharides) are secreted locally and interact among themselves to form an organized structure outside the cell plasma membrane. In unicellular eukaryotic organisms and plant cells, this structure is reinforced to withstand osmotic changes in the external environment, giving rise to the so-called cell wall.