Ichnology of the Miocene Jaraba Formation, Almazán Basin, NE Spain – Morphological characteristics and paleoenvironmental implications of distinct continental trace fossils

2014 ◽  
Vol 274 (1) ◽  
pp. 55-71 ◽  
Author(s):  
Pierre Mueller ◽  
Tom McCann
Keyword(s):  
Morphological Characteristics ◽  
Trace Fossils ◽  
Ne Spain

scholarly journals Apostillas al artículo de Uchman y Alvaro (2000) Non-marine invertebrate trace fossils from the tertiary Calatayud­Teruel Basin, NE Spain

2021 ◽  
Vol 16 (1) ◽  
pp. 166
Author(s):  
Sebastián Calzada
Keyword(s):  
Marine Invertebrate ◽  
Trace Fossils ◽  
Ne Spain

El artículo de Uchman y Alvaro (2000) es sin duda un buen trabajo, por el cual merecen una felicitación, pero cuando tratan el icnogénero Spongeliomorpha, creo dejan de lado algunos aspectos sobre los que me parece oportuno aportar algunas apostillas.

scholarly journals Non-marine invertebrate trace fossils from the Tertiary Calatayud-Teruel basin, NE Spain

2021 ◽  
Vol 15 (2) ◽  
pp. 203
Author(s):  
Alfred Uchman ◽  
Jose Javier Álvaro
Keyword(s):  
Benthic Community ◽  
Marine Invertebrate ◽  
Trace Fossils ◽  
Lacustrine Deposits ◽  
Environmental Transitions ◽  
Moist Ground ◽  
Lines Of Evidence ◽  
Ne Spain

Relatively diverse trace fossils made by insects, other arthropods and oligochaete worms occur in the Miocene lacustrine and marginal lacustrine deposits of the Calatayud-Teruel basin (NE Spain). They include the ichnospecies Celliforma isp., Celliforma? isp. A and B, Celliforma? aff. habari, Rosellichnus cf. arabicus, Spongeliomorpha isp., Labyrintichnus terrerensis n. igen. et isp., Taenidium barreti, Beaconites filiformis n. isp. and Polykladichnus aragonensis n. isp. Their taxonomic and ethologic interpretations and cross-cutting relationships permit to envisage new lines of evidence for reconstructing transitions from dry-ground terrestrial to moist-ground and subaqueous environments, related to episodic floodings in lacustrine ponds. These environmental transitions (related to external controls) are characterized by benthic community replacements, evinced by vertical successions of Termitichnus, Scoyenia and Mermia-like ichnofacies. 

Cell Wall Ultrastructure in Three Strains of a Cariogenic Streptococcus

1971 ◽  
Vol 29 ◽  
pp. 338-339
Author(s):  
M. J. Kramer ◽  
Alan L. Coykendall
Keyword(s):  
Cell Wall ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Genetic Heterogeneity ◽  
Morphological Characteristics ◽  
Electron Microscopic ◽  
Dna Reassociation ◽  
Wall Ultrastructure

During the almost 50 years since Streptococcus mutans was first suggested as a factor in the etiology of dental caries, a multitude of studies have confirmed the cariogenic potential of this organism. Streptococci have been isolated from human and animal caries on numerous occasions and, with few exceptions, they are not typable by the Lancefield technique but are relatively homogeneous in their biochemical reactions. An analysis of the guanine-cytosine (G-C) composition of the DNA from strains K-1-R, NCTC 10449, and FA-1 by one of us (ALC) revealed significant differences and DNA-DNA reassociation experiments indicated that genetic heterogeneity existed among the three strains. The present electron microscopic study had as its objective the elucidation of any distinguishing morphological characteristics which might further characterize the respective strains.

Aberrant Type C Virus Production in a Cell Line Derived from Balb/3T3

1972 ◽  
Vol 30 ◽  
pp. 286-287
Author(s):  
N. Savage ◽  
A. Hackett
Keyword(s):  
Electron Microscopy ◽  
Cell Line ◽  
Leukemia Virus ◽  
Morphological Characteristics ◽  
Virus Production ◽  
Oncogenic Viruses ◽  
Endogenous Virus ◽  
Virus Particles ◽  
Moloney Leukemia Virus ◽  
A Cell

A cell line, UC1-B, which was derived from Balb/3T3 cells, maintains the same morphological characteristics of the non-transformed parental culture, and shows no evidence of spontaneous virus production. Survey by electron microscopy shows that the cell line consists of spindle-shaped cells with no unusual features and no endogenous virus particles.UC1-B cells respond to Moloney leukemia virus (MLV) infection by a change in morphology and growth pattern which is typical of cells transformed by sarcoma virus. Electron microscopy shows that the cells are now variable in shape (rounded, rhomboid, and spindle), and each cell type has some microvilli. Virtually all (90%) of the cells show virus particles developing at the cell surface and within the cytoplasm. Maturing viruses, typical of the oncogenic viruses, are found along with atypical tubular forms in the same cell.

DNA nick end labeling: a reliable marker for apoptosis?

1995 ◽  
Vol 53 ◽  
pp. 962-963
Author(s):  
Anne F. Bushnell ◽  
Sarah Webster ◽  
Lynn S. Perlmutter
Keyword(s):  
Cell Death ◽  
Cultured Cells ◽  
Apoptotic Cell ◽  
Morphological Characteristics ◽  
Detection Methods ◽  
Tissue Preparation ◽  
Preparation Methods ◽  
Dna Laddering ◽  
Disease States ◽  
Reliable Marker

Apoptosis, or programmed cell death, is an important mechanism in development and in diverse disease states. The morphological characteristics of apoptosis were first identified using the electron microscope. Since then, DNA laddering on agarose gels was found to correlate well with apoptotic cell death in cultured cells of dissimilar origins. Recently numerous DNA nick end labeling methods have been developed in an attempt to visualize, at the light microscopic level, the apoptotic cells responsible for DNA laddering.The present studies were designed to compare various tissue processing techniques and staining methods to assess the occurrence of apoptosis in post mortem tissue from Alzheimer's diseased (AD) and control human brains by DNA nick end labeling methods. Three tissue preparation methods and two commercial DNA nick end labeling kits were evaluated: the Apoptag kit from Oncor and the Biotin-21 dUTP 3' end labeling kit from Clontech. The detection methods of the two kits differed in that the Oncor kit used digoxigenin dUTP and anti-digoxigenin-peroxidase and the Clontech used biotinylated dUTP and avidinperoxidase. Both used 3-3' diaminobenzidine (DAB) for final color development.

SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

1990 ◽  
Vol 48 (3) ◽  
pp. 58-59
Author(s):  
Daryl A. Cornish ◽  
George L. Smit
Keyword(s):  
Morphological Characteristics ◽  
Oreochromis Mossambicus ◽  
Breeding Cycle ◽  
Limited Information ◽  
North West ◽  
The North ◽  
Sem And Tem ◽  
Sperm Development ◽  
Ultrastructural Characteristics ◽  
The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

Approaches for TEM imaging of cavitation in toughened nylon

1989 ◽  
Vol 47 ◽  
pp. 352-353
Author(s):  
Barbara A. Wood
Keyword(s):  
Morphological Characteristics ◽  
Structure Property ◽  
Polymer Systems ◽  
Selective Staining ◽  
Structure Property Relationships ◽  
Rubber Toughened ◽  
Shear Yield ◽  
Controversial Topic ◽  
Selection Of ◽  
Diamond Knife

A controversial topic in the study of structure-property relationships of toughened polymer systems is the internal cavitation of toughener particles resulting from damage on impact or tensile deformation.Detailed observations of the influence of morphological characteristics such as particle size distribution on deformation mechanisms such as shear yield and cavitation could provide valuable guidance for selection of processing conditions, but TEM observation of damaged zones presents some experimental difficulties.Previously published TEM images of impact fractured toughened nylon show holes but contrast between matrix and toughener is lacking; other systems investigated have clearly shown cavitated impact modifier particles. In rubber toughened nylon, the physical characteristics of cavitated material differ from undamaged material to the extent that sectioning of heavily damaged regions by cryoultramicrotomy with a diamond knife results in sections of greater than optimum thickness (Figure 1). The detailed morphology is obscured despite selective staining of the rubber phase using the ruthenium trichloride route to ruthenium tetroxide.

Variation of the morphological characteristics and active principles in wild and cultivated Gentiana lutea L. from Romania

Planta Medica ◽  
2007 ◽  
Vol 73 (09) ◽  
Author(s):  
M Tanase ◽  
C Sand ◽  
D Bobit ◽  
D Lazurca ◽  
M Boncut ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Gentiana Lutea
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