Paleokarstic macroporosity development at platform margins: Lessons from the Paleocene of north Spain

2014 ◽  
Vol 2 (3) ◽  
pp. SF1-SF16 ◽  
Author(s):  
V. Paul Wright ◽  
Juan Ignacio Baceta ◽  
Philippe A. Lapointe
Keyword(s):  
Quantitative Data ◽  
Semiarid Climate ◽  
Platform Margin ◽  
Stratigraphic Record ◽  
Fracture Intensity ◽  
Karstic Features ◽  
The Caribbean ◽  
Flank Margin Caves

Platform margins have been targets for carbonate exploration because they are commonly seismically resolvable and reservoir prone for several critical reasons including karstic porosity. Platform margin karst models, mainly based on the Quaternary of the Caribbean (tropical humid, including “flank margin caves”) are well documented, but analogs remain rarely identified in the stratigraphic record. Analysis of a remarkably well-exposed macroporosity paleokarst system from the Paleocene of north Spain, formed under an arid to semiarid climate, provided a model that differs from the Caribbean template. Implications for exploration and appraisal strategies, include provisos regarding (1) how early fracture intensity can be estimated at platform margins, (2) the absence of flank margin caves at the margin, (3) the absence of karstic features at or immediately below the main lowstand surface, (4) the presence of cave-free corridors such that the porosity zones could be missed completely, and (5) the stratigraphic inheritance of caves into successive levels adjacent to the cave-free zones. Quantitative data were evaluated on the main macroporous intervals. We also compared this model with other paleokarst models in the literature to emphasize the diversity of approaches that can be used to evaluate paleokarst targets: “one size does not fit all.”

Educating Caribbean Librarians to Provide Library Education in a Dynamic Information Environment

2017 ◽  
pp. 187-226
Author(s):  
Ruth Baker-Gardner ◽  
Paulette Stewart
Keyword(s):  
Quantitative Data ◽  
Information Science ◽  
Library And Information Science ◽  
Teaching Competencies ◽  
Online Programs ◽  
Library Education ◽  
Faculty Qualifications ◽  
The Caribbean ◽  
Teacher Librarians ◽  
Method Approach

The dynamism of the information sector driven by ICT and the resulting impact on library and information science professionals have resulted in significant changes in how teaching librarians in the Caribbean are educated. This research was conducted to: describe the education of teaching librarians; examine the changes in education; and investigate how teaching librarians develop and hone their teaching competencies. A mixed-method approach was used to garner quantitative data from 45 librarians and qualitative data from relevant documents in two library schools. The findings show there were significant changes as new courses and programs were developed, online programs were implemented and faculty qualifications upgraded. These changes were somewhat effective, however, teacher-librarians, who developed teaching skills mainly from teacher training, expressed a need for additional technology skills to make them more effective. It was recommended that LIS schools need to diversify their programs to make the content and the activities more aligned to the day to day practices of these teacher librarians.

Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Near Surface ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Platform Margin ◽  
Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

Metallurgical Effects of Grain Boundary Ledges

1977 ◽  
Vol 35 ◽  
pp. 126-129
Author(s):  
L.E. Murr
Keyword(s):  
Grain Boundary ◽  
Quantitative Data ◽  
Mechanical Treatment ◽  
Unit Length ◽  
Physical And Mechanical Properties ◽  
Direct Observations ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Thermo Mechanical Treatment ◽  
Ledge Density

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.

Morphometric analysis of cellular interactions with the endothelium during the development of arterial lesions using Scanning Electron Microscopy and digital image analysis

1987 ◽  
Vol 45 ◽  
pp. 918-919
Author(s):  
M.E. Rosenfeld ◽  
C. Karboski ◽  
M.F. Prescott ◽  
P. Goodwin ◽  
R. Ross
Keyword(s):  
Electron Microscopy ◽  
Image Analysis ◽  
Quantitative Data ◽  
Digital Image Analysis ◽  
Lower Cost ◽  
Matched Control ◽  
Digital Analysis ◽  
Cellular Interactions ◽  
Arterial Lesions ◽  
Scanning Electron

Previous research documenting the chronology of the cellular interactions that occur on or below the surface of the endothelium during the initiation and progression of arterial lesions, primarily consisted of descriptive studies. The recent development of lower cost image analysis hardware and software has facilitated the collection of high resolution quantitative data from microscopic images. In this report we present preliminary quantitative data on the sequence of cellular interactions that occur on the endothelium during the initiation of atherosclerosis or vasculitis utilizing digital analysis of images obtained directly from the scanning electron microscope. Segments of both atherosclerotic and normal arteries were obtained from either diet-induced or endogenously (WHHL) hypercholesterolemic rabbits following 1-4 months duration of hypercholesterolemia and age matched control rabbits. Vasculitis was induced in rats following placement of an endotoxin soaked thread adjacent to the adventitial surface of arteries.

Motility of leukemic lymphocytes

1990 ◽  
Vol 48 (3) ◽  
pp. 368-369
Author(s):  
Manoj Raje ◽  
Karvita B. Ahluwalia
Keyword(s):  
Quantitative Data ◽  
Laser Doppler Velocimetry ◽  
Acute Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Cellular Space ◽  
Differentiated Cells ◽  
Poorly Differentiated ◽  
Solid Tissues ◽  
Well Differentiated ◽  
Reduced Mobility

In Acute Lymphocytic Leukemia motility of lymphocytes is associated with dissemination of malignancy and establishment of metastatic foci. Normal and leukemic lymphocytes in circulation reach solid tissues where due to in adequate perfusion some cells get trapped among tissue spaces. Although normal lymphocytes reenter into circulation leukemic lymphocytes are thought to remain entrapped owing to reduced mobility and form secondary metastasis. Cell surface, transmembrane interactions, cytoskeleton and level of cell differentiation are implicated in lymphocyte mobility. An attempt has been made to correlate ultrastructural information with quantitative data obtained by Laser Doppler Velocimetry (LDV). TEM of normal & leukemic lymphocytes revealed heterogeneity in cell populations ranging from well differentiated (Fig. 1) to poorly differentiated cells (Fig. 2). Unlike other cells, surface extensions in differentiated lymphocytes appear to originate by extrusion of large vesicles in to extra cellular space (Fig. 3). This results in persistent unevenness on lymphocyte surface which occurs due to a phenomenon different from that producing surface extensions in other cells.

Delusions in the Caribbean

1963 ◽  
Vol 8 (2) ◽  
pp. 69-70
Author(s):  
WALTER MISCHEL
Keyword(s):  
The Caribbean
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