scholarly journals Memoirs: Studies in Spicule Formation

1908 ◽  
Vol s2-52 (205) ◽  
pp. 139-157
Author(s):  
W. WOODLAND
Keyword(s):  
Thin Film ◽  
Single Cells ◽  
Siliceous Sponge ◽  
Sponge Spicule ◽  
Calcareous Sponges ◽  
Stage Of Development ◽  
Spicule Formation

1. The earliest stages in development of the Hexactinellid spicule are at present unknown, but there exist reasons for supposing that it originates as a granule enclosed by a spherical syncytium in which cell-outlines are absent, and that the six rays of the hexact grow out from this granule. 2. The earliest stage of development yet discovered is the small hexact, the rays of which do not extend to the periphery of the enveloping syncytium. 3. The rays of the hexact elongate, causing the spherical syncytium at first "to present a more or less octahedral shape, with somewhat concave surfaces and with rounded corners" (Ijima). 4. The rays at length extend beyond the spherical contour of the syncytium (the scleroblast mass), the scleroplasm of which, however, persistently adheres to the rays as a thin film, which occasionally includes nuclei. 5. The peripheral growth of the megasclere type of spicule causes the spherical syncytium enveloping the point of junction of the six rays to dwindle and finally to disappear on account of the distension involved. The whole of the microsclere, with the exception of the terminals, remains permanently enveloped by the spherical syncytium. 6. All tetractinellid and monactinellid spicules originate as granules contained within single cells. In a few instances the spicule arises from several granules within the cell and then consists of separate parts (dragmata, for example). 7. All growth is accretionary. There is no well-authenticated instance of a siliceous sponge-spicule being formed by the fusion of at-first-separate parts--such as occurs in calcareous sponges, for example. 8. With the exception of very large spicules, the nucleus of the distended scleroblast remains single throughout growth. 9. It is a significant fact that spicule formation proceeds on very different lines in each of the three great groups of sponges--the Tetraxonida, Triaxonida, and Calcarea.

Flexible, Monolithically Integrated Cu(In,Ga)Se2 Thin-Film Solar Modules

2005 ◽  
Vol 865 ◽  
Author(s):  
Dirk Herrmann ◽  
Friedrich Kessler ◽  
Ulf Klemm ◽  
Robert Kniese ◽  
Theresa Magorian Friedlmeier ◽  
...  
Keyword(s):  
Thin Film ◽  
Production Process ◽  
Low Cost ◽  
Single Cells ◽  
Production Method ◽  
Flexible Substrates ◽  
Metal Foil ◽  
Monolithically Integrated ◽  
Glass Substrates ◽  
Roll To Roll

AbstractCIGS (Cu(In,Ga)Se2) thin-film solar modules on glass substrates are currently on the verge of commercialization. Entirely new application areas could be accessed with CIGS modules fabricated on thin and flexible non-glass substrates. Additionally, the roll-to-roll manufacturing of such flexible CIGS modules promises to be a low-cost production method. Different external Na supply methods and a vacuum-deposited buffer were investigated in this contribution, a sample of the challenges we face when modifying the standard, industrial CIGS module production process to the particular requirements of flexible substrates. Both metal foil substrates and polymer films are considered. Our excellent best results of above 14 % for single cells on titanium, more than 11% on polyimide, and around 7 % for modules on both substrates indicate our progress in developing flexible CIGS.

Occurrence of the siliceous sponge spicule Konyrium (Hexactinellida) in the upper Cambrian of the Mackenzie Mountains, northwestern Canada

2002 ◽  
Vol 76 (3) ◽  
pp. 565-569 ◽  
Author(s):  
Brian R. Pratt
Keyword(s):  
Fossil Record ◽  
Southern China ◽  
South Australia ◽  
Early Cambrian ◽  
Siliceous Sponge ◽  
Sponge Spicule ◽  
Animal Phyla ◽  
Sponge Diversity ◽  
Siliceous Sponges ◽  
Late Neoproterozoic

The fossil record of siliceous sponges—Hexactinellida and demosponge “Lithistida”—hinges upon both body fossils plus isolated spicules mostly recovered from limestones by acid digestion. The earliest record of siliceous sponge spicules extends back to the late Neoproterozoic of Hubei, southern China (Steiner et al., 1993) and Mongolia (Brasier et al., 1997), and body fossils attributed to the hexactinellids have been described from the Ediacaran of South Australia (Gehling and Rigby, 1996); thus they are the oldest-known definite representatives of extant animal phyla. The Early Cambrian saw a remarkable diversification in spicule morphology, with the appearance of an essentially “modern” array of forms (Zhang and Pratt, 1994). While a diversity decline may have occurred with the late Early Cambrian extinction(s), the subsequent Paleozoic and Mesozoic fossil record of spicules shows a relatively consistent range of morphologies (e.g., Mostler, 1986; Bengtson et al., 1990; Webby and Trotter, 1993; Kozur et al., 1996; Zhang and Pratt, 2000). However, because spicule form is not restricted to individual taxa and many sponge species secrete a variety of spicule shapes, it is difficult to gauge true siliceous sponge diversity and to explore their biostratigraphic utility using only isolated spicules.

A new Gorstian radiolarian fauna from the upper Silurian of the Cape Phillips Formation, Cornwallis and Bathurst islands, Canadian Arctic

2015 ◽  
Vol 52 (10) ◽  
pp. 863-879 ◽  
Author(s):  
Martin Tetard ◽  
Paula J. Noble ◽  
Taniel Danelian ◽  
Claude Monnet ◽  
Alfred C. Lenz
Keyword(s):  
Canadian Arctic ◽  
Alpha Diversity ◽  
Siliceous Sponge ◽  
Sponge Spicule ◽  
Cape Phillips Formation ◽  
Cortical Shell ◽  
Stratigraphic Ranges ◽  
Shelf Margin ◽  
Cornwallis Island

This study provides a taxonomic treatment and comparison of lower Gorstian (Silurian) radiolarians recovered from two sections of the Cape Phillips Formation in the Canadian Arctic that accumulated in two different paleoenvironmental settings. Twilight Creek is more basinal, located ∼100 km from the paleo-shelf margin, whereas Snowblind Creek is located within 1 km of the paleo-shelf break, on Cornwallis Island. The fauna, like other material from the Cape Phillips Formation, is extremely well preserved and was recovered from four samples at two localities, all from the Lobograptus progenitor graptolite Zone, an interval that has few published studies regarding radiolarians. A total of 28 species are recognized, of which two are new and described herein (Fusalfanus bilateralis n. sp. and Pseudospongoprunum parvispina n. sp.), belonging to the Haplotaeniatidae, Inaniguttidae, “Sponguridae”, Ceratoikiscidae, Entactiniidae, Palaeoscenidiidae, and Secuicollactidae. Based on these new data, the stratigraphic ranges of some taxa are extended. The species concepts of several closely related inaniguttid species are re-evaluated. As a result, Inanihella tarangulica Nazarov and Ormiston, 1984 is transferred to the genus Fusalfanus Furutani, 1990 based on cortical shell structure, and Inanihella duroacus, Inanihella legiuncula, and Inanihella perarmata are synonymized under Fusalfanus tarangulica sensu lato. Aciferopylorum admirandum is transferred to Fusalfanus and considered a junior synonym of Fusalfanus osobudaniensis. The comparative analysis of taxonomic richness and composition reveals that the more distal sample from Bathurst Island exhibits a slight, but statistically significant, higher alpha diversity at the species rank than the more proximal basin/platform samples from Snowblind Creek. Biodiversity indices at the genus rank produced mixed results, indicating that differences between sites are at best slight. There is also a strong taxonomic separation between the fine and coarse size radiolarian fractions recovered during the sieving of each sample. The siliceous sponge spicule assemblages from these faunas show an inverse diversity relationship to the radiolarians in that Snowblind Creek contains greater alpha diversity than Twilight Creek. This study provides the first documentation of facies-controls in Silurian radiolarian diversity and is useful in evaluating the role of taxa used in biostratigraphy.

scholarly journals Spicule formation in calcareous sponges: Coordinated expression of biomineralization genes and spicule-type specific genes

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Oliver Voigt ◽  
Maja Adamska ◽  
Marcin Adamski ◽  
André Kittelmann ◽  
Lukardis Wencker ◽  
...  
Keyword(s):  
Calcareous Sponges ◽  
Spicule Formation ◽  
Coordinated Expression

A thin film albumin method for encapsulating single cells for ultramicrotomy

1982 ◽  
Vol 14 (6) ◽  
pp. 999-1001 ◽  
Author(s):  
M. H. Walker ◽  
E. M. Roberts
Keyword(s):  
Thin Film ◽  
Single Cells

ChemInform Abstract: Genetic, Biological and Structural Hierarchies During Sponge Spicule Formation: from Soft Sol-Gels to Solid 3D Silica Composite Structures

ChemInform ◽  
2012 ◽  
Vol 43 (46) ◽  
pp. no-no
Author(s):  
Xiaohong Wang ◽  
Heinz C. Schroeder ◽  
Kui Wang ◽  
Jaap A. Kaandorp ◽  
Werner E. G. Mueller
Keyword(s):  
Composite Structures ◽  
Sponge Spicule ◽  
Silica Composite ◽  
Spicule Formation

Siliceous sponge spicule dissolution: In field experimental evidences from temperate and tropical waters

2017 ◽  
Vol 184 ◽  
pp. 46-53 ◽  
Author(s):  
Marco Bertolino ◽  
Riccardo Cattaneo-Vietti ◽  
Maurizio Pansini ◽  
Chiara Santini ◽  
Giorgio Bavestrello
Keyword(s):  
Siliceous Sponge ◽  
Sponge Spicule ◽  
Tropical Waters

scholarly journals FINE STRUCTURE AND COMPOSITION OF A SILICEOUS SPONGE SPICULE

1971 ◽  
Vol 140 (1) ◽  
pp. 125-136 ◽  
Author(s):  
DANIEL W. SCHWAB ◽  
RICHARD E. SHORE
Keyword(s):  
Fine Structure ◽  
Siliceous Sponge ◽  
Sponge Spicule

scholarly journals Scaling single cell transcriptomics through split pool barcoding

2017 ◽  
Author(s):  
Alexander B. Rosenberg ◽  
Charles M. Roco ◽  
Richard A. Muscat ◽  
Anna Kuchina ◽  
Sumit Mukherjee ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Main Tool ◽  
Cell Types ◽  
Single Experiment ◽  
Laboratory Equipment ◽  
Cellular Origin ◽  
Stage Of Development ◽  
Collective Effort ◽  
Different Types

Constructing an atlas of cell types in complex organisms will require a collective effort to characterize billions of individual cells. Single cell RNA sequencing (scRNA-seq) has emerged as the main tool for characterizing cellular diversity, but current methods use custom microfluidics or microwells to compartmentalize single cells, limiting scalability and widespread adoption. Here we present Split Pool Ligation-based Transcriptome sequencing (SPLiT-seq), a scRNA-seq method that labels the cellular origin of RNA through combinatorial indexing. SPLiT-seq is compatible with fixed cells, scales exponentially, uses only basic laboratory equipment, and costs one cent per cell. We used this approach to analyze 109,069 single cell transcriptomes from an entire postnatal day 5 mouse brain, providing the first global snapshot at this stage of development. We identified 13 main populations comprising different types of neurons, glia, immune cells, endothelia, as well as types in the blood-brain-barrier. Moreover, we resolve substructure within these clusters corresponding to cells at different stages of development. As sequencing capacity increases, SPLiT-seq will enable profiling of billions of cells in a single experiment.

Sign in / Sign up

Export Citation Format

Share Document