Search results for "Rite"
showing 10 items of 2726 documents
Differentiation capacity of epithelial cells in the sponge Suberites domuncula.
2004
Sponges (phylum Porifera) represent the oldest metazoans. Their characteristic metazoan adhesion molecules and transcription factors enable them to establish a complex "Bauplan" ; three major differentiated cell types (epithelial cells, skeletal cells/sclerocytes, and contractile cells) can be distinguished. Since no molecular markers are as yet available to distinguish these somatic cells or the corresponding embryonic cells from which they originate, we have selected the following three genes for their characterization: noggin (a signaling molecule in development), a caspase that encodes an apoptotic molecule, and silicatein. Silicatein is an enzyme that is involved in the synthesis of si…
Imaging connected porosity of crystalline rock by contrast agent-aided X-ray microtomography and scanning electron microscopy
2017
We set out to study connected porosity of crystalline rock using X-ray microtomography and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) with caesium chloride as a contrast agent. Caesium is an important radionuclide regarding the final deposition of nuclear waste and also forms dense phases that can be readily distinguished by X-ray microtomography and SEM-EDS. Six samples from two sites, Olkiluoto (Finland) and Grimsel (Switzerland), where transport properties of crystalline rock are being studied in situ, were investigated using X-ray microtomography and SEM-EDS. The samples were imaged with X-ray microtomography, immersed in a saturated caesium chlorid…
Histochemical and electron microscopic analysis of spiculogenesis in the demosponge Suberites domuncula.
2006
The skeleton of demosponges is built of spicules consisting of biosilica. Using the primmorph system from Suberites domuncula, we demonstrate that silicatein, the biosilica-synthesizing enzyme, and silicase, the catabolic enzyme, are colocalized at the surface of growing spicules as well as in the axial filament located in the axial canal. It is assumed that these two enzymes are responsible for the deposition of biosilica. In search of additional potential structural molecules that might guide the mineralization process during spiculogenesis to species-specific spicules, electron microscopic studies with antibodies against galectin and silicatein were performed. These studies showed that …
Evil lords, benign historians: strongman politics in medieval India and Renaissance Florence
2019
Recent developments in Europe and the United States (US) attest to an increasing fascination with and nostalgia for the strong leaders of the past – especially those that emerged in the aftermath o...
Former students of the Riga Polytechnicum and Riga Polytechnic Institute (1862–1919) – literary workers
2018
The authors of the article have gathered literary works of poets and writers – former students of Riga Polytechnicum (RP) and Riga Polytechnic institute (RPI), and have characterized them. Several Latvian and foreign literary workers have studied at the institute. Only six of them – Alfrēds Andersons, Jānis Bergs, Rihards Ērglis, Ernests Eferts, Jānis Miķelsons and Arvīds Valdmanis – received diplomas in engineering after graduating from Departments of Engineering, Commerce and Agriculture. A. Valdmanis has written course books and literary works. Latvian poet Jānis Poruks and Russian writer Mihail Prishvin (Михаил Михаилович Пришвин) have also studied at the institute, but just like few ot…
Speciation of neptunium during sorption and diffusion in natural clay
2016
In argillaceous rocks, which are considered as a potential host rock for nuclear waste repositories, sorption and diffusion processes govern the migration behaviour of actinides like neptunium. For the safety analysis of such a repository, a molecular-level understanding of the transport and retardation phenomena of radioactive contaminants in the host rock is mandatory. The speciation of Np during sorption and diffusion in Opalinus Clay was studied at near neutral pH using a combination of spatially resolved synchrotron radiation techniques. During the sorption and diffusion experiments, the interaction of 8 μM Np(V) solutions with the clay lead to the formation of spots at the clay-water …
Learning from the Past : The Women Writers Project and Thirty Years of Humanities Text Encoding
2017
In recent years, intensified attention in the humanities has been paid to data: to data modeling, data visualization, “big data”. The Women Writers Project has dedicated significant effort over the past thirty years to creating what Christoph Schöch calls “smart clean data”: a moderate-sized collection of early modern women’s writing, carefully transcribed and corrected, with detailed digital text encoding that has evolved in response to research and changing standards for text representation. But that data—whether considered as a publication through Women Writers Online, or as a proof of the viability of text encoding approaches like those expressed in the Text Encoding Initiative (TEI) Gu…
How to Become an Author: The Poet Isa Asp and Her Childhood Fascination with Writing for Magazines
2021
In this article the author explores the early development of the identity as a writer of a Finnish-speaking poet Lovisa (or Isa) Asp (1853–1872). She wrote her lyrics in the Finnish language in the 1870s, and she is regarded as the first 19th-century female Finnish poet (whose works were published in Finnish). She began writing poetry (initially in Swedish) as a teenager and started her literary career as a contributor to children’s magazines. Asp began her studies at the Teacher Training College in Jyväskylä in autumn 1871 with the aim of working as an elementary school teacher, but she also dreamt of becoming an established writer someday. Unfortunately, her early death meant that most of…
<p class="HeadingRunIn"><strong>Reinterpretation of the enigmatic Ordovician genus <em>Bolboporites </em>(Echinodermata)</…
2019
Bolboporites is an enigmatic Ordovician cone-shaped fossil, the precise nature and systematic affinities of which have been controversial over almost two centuries. For the first time, a wide range of techniques (CT-scan, SEM, cathodoluminescence, XPL, UV epifluorescence, EBSD, FT-IR and XRF spectrometry) were applied to well-preserved specimens of Bolboporites from Norway and Russia. Our main finding confirms its echinoderm affinities, as shown by its stereomic microstructure and by the first definitive evidence of its monocrystalline nature. Each cone consists in a single, microporous calcitic crystal with a narrow longitudinal internal canal. These results are combined with all previous …
A year in the life of an aluminous metapelite xenolith—The role of heating rates, reaction overstep, H2O retention and melt loss
2011
Abstract Xenoliths of aluminous metapelite within the Platreef magmatic rocks of the Bushveld Complex, South Africa, are mineralogically and texturally zoned, with coarse-grained margins rich in acicular corundum, spinel and feldspar and cores rich in finer-grained aluminosilicate and cordierite. Xenoliths exhibiting remarkably similar features occur within other intrusions, suggesting a common origin. Using a single 3 m wide xenolith as a case study, a model is proposed to explain their petrogenesis. Mineral equilibria calculations in the NCKFMASHTO system show that the thermal stability of the solid phases, in particular corundum, is highly sensitive to the quantity of H 2 O retained in t…