Characterization and Comparative Analysis of Ancient Earthen Plasters from the American Southwest

MRS Advances ◽  
2017 ◽  
Vol 2 (39-40) ◽  
pp. 2145-2178 ◽  
Author(s):  
Angelyn Bass ◽  
Douglas Porter ◽  
Mike Spilde ◽  
Matthew Guebard ◽  
Katherine Shaum ◽  
...  
Keyword(s):  
Native American ◽  
Material Selection ◽  
American Southwest ◽  
Textile Production ◽  
Thin Sections ◽  
National Monument ◽  
Great House ◽  
Ancient People ◽  
Long Term Preservation

ABSTRACT We have studied earthen plasters and wall materials from three ancient Native American sites in the American Southwest that include a twelfth-century, subterranean kiva used for textile production in Natural Bridges National Monument (Utah), a thirteenth-century, defensive, cliff dwelling at Montezuma Castle (Arizona), and a mid-fourteenth-century, puddled earth Great House at Casa Grande National Monument (Arizona). In each case, the data collected has been used to develop long-term preservation strategies and monitoring plans for each site. To understand the conservation issues, earthen materials were analyzed. Characterization included examination of BSE-SEM micrographs of polished thin sections prepared from a total of 36 samples from the three sites, and XRD of twelve samples. Research goals included: 1) determining the microstructure, micro-composition, porosity, mineralogy of aggregates and phases in the binding matrix for each sample; 2) reconstructing plaster technologies and their variation within and between sites, including material selection, preparation and application sequences, and; 3) identifying principal deterioration conditions and processes. Our findings support the idea that plaster materials were collected locally and manipulated to optimize their performance to suit the unique site conditions and needs of the ancient people using the structures.

Unusual Intranuclear Structures in Chick Sympathetic Neurons

1967 ◽  
Vol 25 ◽  
pp. 188-189
Author(s):  
E. B. Masurovsky ◽  
H. H. Benitez ◽  
M. R. Murray
Keyword(s):  
Electron Microscope ◽  
Sympathetic Neurons ◽  
Uranyl Acetate ◽  
Sympathetic Ganglia ◽  
Lead Citrate ◽  
Thin Sections ◽  
Cns Neurons ◽  
Mammalian Cns

Recent light- and electron microscope studies concerned with the effects of D2O on the development of chick sympathetic ganglia in long-term, organized culture revealed the presence of rod-like fibrillar formations, and associated granulofibrillar bodies, in the nuclei of control and deuterated neurons. Similar fibrillar formations have been reported in the nuclei of certain mammalian CNS neurons; however, related granulofibrillar bodies have not been previously described. Both kinds of intranuclear structures are observed in cultures fixed either in veronal acetate-buffered 2%OsO4 (pH 7. 4), or in 3.5% glutaraldehyde followed by post-osmication. Thin sections from such Epon-embedded cultures were stained with ethanolic uranyl acetate and basic lead citrate for viewing in the electron microscope.

Attachment of oral bacteria to titanium surfaces: An SEM study

1994 ◽  
Vol 52 ◽  
pp. 468-469
Author(s):  
J. E. Laffoon ◽  
R. L. Anderson ◽  
J. C. Keller ◽  
C. D. Wu-Yuan
Keyword(s):  
Technical Problem ◽  
Titanium Implant ◽  
Oral Bacteria ◽  
Bacterial Cells ◽  
Thin Sections ◽  
Surface Ultrastructure ◽  
Sem Study ◽  
Key Factor ◽  
Titanium Surfaces

Titanium (Ti) dental implants have been used widely for many years. Long term implant failures are related, in part, to the development of peri-implantitis frequently associated with bacteria. Bacterial adherence and colonization have been considered a key factor in the pathogenesis of many biomaterial based infections. Without the initial attachment of oral bacteria to Ti-implant surfaces, subsequent polymicrobial accumulation and colonization leading to peri-implant disease cannot occur. The overall goal of this study is to examine the implant-oral bacterial interfaces and gain a greater understanding of their attachment characteristics and mechanisms. Since the detailed cell surface ultrastructure involved in attachment is only discernible at the electron microscopy level, the study is complicated by the technical problem of obtaining titanium implant and attached bacterial cells in the same ultra-thin sections. In this study, a technique was developed to facilitate the study of Ti implant-bacteria interface.Discs of polymerized Spurr’s resin (12 mm x 5 mm) were formed to a thickness of approximately 3 mm using an EM block holder (Fig. 1). Titanium was then deposited by vacuum deposition to a film thickness of 300Å (Fig. 2).

Problems of treatment of primary openangle glaucoma in combination with thrombosis of the central retinal vein

GlaucomaNews ◽  
2020 ◽  
pp. 65-69
Author(s):  
T.E. Lipatkina ◽  
◽  
Е.V. Karlova ◽  
A.V. Zolotarev ◽  
◽  
...  
Keyword(s):  
Macular Edema ◽  
Primary Open Angle Glaucoma ◽  
Antihypertensive Drugs ◽  
Open Angle Glaucoma ◽  
Vascular Wall ◽  
Open Angle ◽  
Retinal Edema ◽  
Long Term Preservation ◽  
Central Retinal Vein

Patients with primary open-angle glaucoma (POAG) and ophthalmic hypertension have an increased likelihood of developing occlusions (thrombosis) of the central retinal vein. Different groups of antihypertensive drugs differ in their mechanism of action and may affect concomitant ocular pathology, in particular, retinal edema, which occurs, for example, in occlusion of the central retinal vein. Used in most patients with glaucoma, prostaglandin analogs can contribute to the long-term preservation of macular edema due to the effect on the permeability of the vascular wall. Preparations of other pharmacological groups, reducing the production of aqueous humor, on the contrary, may contribute to its regression. Therefore, the question of choosing a drug for antihypertensive therapy in patients with primary open-angle glaucoma and concomitant macular edema is relevant and is for further study.

Vertebrate paleontology, stratigraphy, and paleohydrology of Tule Springs Fossil Beds National Monument, Nevada (USA)

2017 ◽  
Vol 4 ◽  
pp. 55-98
Author(s):  
Kathleen Springer ◽  
Jeffrey Pigati ◽  
Eric Scott
Keyword(s):  
Las Vegas ◽  
Late Quaternary ◽  
Plant Macrofossils ◽  
Distinct Species ◽  
American Southwest ◽  
Local Fauna ◽  
Climatic Oscillations ◽  
Las Vegas Valley ◽  
National Monument ◽  
Desert Wetlands

Tule Springs Fossil Beds National Monument (TUSK) preserves 22,650 acres of the upper Las Vegas Wash in the northern Las Vegas Valley (Nevada, USA). TUSK is home to extensive and stratigraphically complex groundwater discharge (GWD) deposits, called the Las Vegas Formation, which represent springs and desert wetlands that covered much of the valley during the late Quaternary. The GWD deposits record hydrologic changes that occurred here in a dynamic and temporally congruent response to abrupt climatic oscillations over the last ~300 ka (thousands of years). The deposits also entomb the Tule Springs Local Fauna (TSLF), one of the most significant late Pleistocene (Rancholabrean) vertebrate assemblages in the American Southwest. The TSLF is both prolific and diverse, and includes a large mammal assemblage dominated by Mammuthus columbi and Camelops hesternus. Two (and possibly three) distinct species of Equus, two species of Bison, Panthera atrox, Smilodon fatalis, Canis dirus, Megalonyx jeffersonii, and Nothrotheriops shastensis are also present, and newly recognized faunal components include micromammals, amphibians, snakes, and birds. Invertebrates, plant macrofossils, and pollen also occur in the deposits and provide important and complementary paleoenvironmental information. This field compendium highlights the faunal assemblage in the classic stratigraphic sequences of the Las Vegas Formation within TUSK, emphasizes the significant hydrologic changes that occurred in the area during the recent geologic past, and examines the subsequent and repeated effect of rapid climate change on the local desert wetland ecosystem.

Comparison of Polarized and Depolarized Arrest in the Isolated Rat Heart for Long-term Preservation

Circulation ◽  
1997 ◽  
Vol 96 (9) ◽  
pp. 3148-3156 ◽  
Author(s):  
A. K. Snabaitis ◽  
M. J. Shattock ◽  
D. J. Chambers
Keyword(s):  
Rat Heart ◽  
Isolated Rat Heart ◽  
Long Term Preservation ◽  
Isolated Rat

Online Publication of Monuments

2020 ◽  
pp. 355-369
Author(s):  
Willeke Wendrich
Keyword(s):  
Peer Review ◽  
3D Modeling ◽  
Online Publication ◽  
New Technologies ◽  
3D Scanning ◽  
Architectural Drawings ◽  
3D Gis ◽  
Unity 3D ◽  
Long Term Preservation

This chapter outlines the advantages of digital epigraphy in the context of the original monuments. It analyzes the perception of epigraphic publication of monuments, taking into account new technologies. 3DVR models can be created using architectural drawings and measurements (CAD and 3D modeling), 3D scanning, and Structure for Motion (SfM). These systems present different advantages and challenges, which are discussed. Current options for publication include VSim, 3D GIS, and Unity 3D platforms. The issues of peer review of publications and long-term preservation of data are addressed. The chapter concludes with a consideration of the issue of potentially misleading impressions given by 3DVR representations.

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