A West Indian Ax from Florida

1948 ◽  
Vol 13 (4Part1) ◽  
pp. 323-325 ◽  
Author(s):  
John M. Goggin ◽  
Irving Rouse
Keyword(s):  
Cross Section ◽  
West Indian ◽  
The Other ◽  
Strongly Convex ◽  
Alachua County ◽  
State Museum

A stone ax of West Indian type is included among the collections from north Florida in the Florida State Museum (cat. no. 3535). In view of the ever-interesting question of Antillean-Floridian relationships, this specimen seems worth considering in some detail.Information in the Florida State Museum catalog indicates that the ax was received in 1914 from A. W. Sargent of Gainesville who found it on the surface near Newnan's Lake, Alachua County. This is about five miles east of Gainesville. It was accompanied by the base of a spearhead, an arrowhead, and a sherd of St. Johns Check Stamped pottery (cat. nos. 3536-3538).The ax has a roughly rectangular blade; shallow, grooved neck; and broad butt, with a large ear-like projection on either side of the butt and a pair of smaller ones on top (Fig. 55). In cross section, one side is strongly convex and the other partially flattened, so that the artifact might more properly be called an “adze.” Its length is 15.8 cm. and its width 10.9 cm.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

Effective, Shortened Drying of Agar-Gelcasting Al2O3 Tube Through Immersing in Acetone

2021 ◽  
Author(s):  
Ramnaree Kaemkit ◽  
Supawan Vichaphund ◽  
Anukorn Phureungrat ◽  
Methee Promsawat ◽  
Suksawat Sirijarukul ◽  
...  
Keyword(s):  
Cross Section ◽  
Concentration Gradient ◽  
Water Concentration ◽  
Drying Shrinkage ◽  
The Other ◽  
Air Drying ◽  
Al2o3 Tube ◽  
Acetone Water ◽  
Porous Microstructure ◽  
Glass Tubes

Abstract A liquid drying agent, i.e. acetone, was employed for allowing the faster drying of Al2O3 tubes fabricated by agar gelcasting than the conventional air drying. The mixture of Al2O3 slurry and agar solution was separately prepared and then mixed prior to molding out of a set of warmed glass tubes. After the mixture transformed into gelled tube, the gelled tube was demolded and then immersed in acetone at different periods of time from 0 to 50 h. The immersed periods of 50 h led to the acetone replacement for water being inside of the gelling tube by 74 wt.% and then shortened the drying period to be 25 min. On the other hand, the conventional air drying spent 420 min drying completely. After drying, the immersed tubes possessed spherical cross section; whereas, no immersed tubes showed the deformation of cross section. The shortened drying was in line with the smaller drying shrinkage (4.7%), broader pore-size distribution and higher porous microstructure, comparing to the conventional air drying. The mechanism of acetone replacement for water was attributed to the acetone-water concentration gradient creating their inter-diffusion.

The Defect Structure of BaTiO3 Thin Films

1993 ◽  
Vol 310 ◽  
Author(s):  
L.A. Wills ◽  
B.W. Wessels
Keyword(s):  
Thin Films ◽  
Cross Section ◽  
Defect Structure ◽  
Oxygen Vacancies ◽  
Vacuum Annealing ◽  
Deep Level ◽  
Energy Levels ◽  
The Other ◽  
Optical Cross Section ◽  
Impurity Defects

AbstractThe defect structure of BaTiO3 thin films grown on (100) Si was examined using transient photocapacitance spectroscopy. The concentration, optical cross section and associated energy levels of both native and impurity defects in as-grown and annealed BaTiO3 films were evaluated. Deep level defects withpeak energies of Ev+1.8, Ev+2.4, Ev+2.7, Ev+3.0-3.1 and Ev+3.2-3.3 eV were observed in the as-grown films. Upon vacuum annealing, the concentration of the traps at Ev+3.0 and Ev+3.2 eV increased while the concentration of the traps at Ev+ 1.8 and Ev+2.4 eV decreased. The levels at Ev+3.0-3.1 and Ev+3.2-3.3 eV are attributed to oxygen vacancies. The other levels are tentatively ascribed to Fe and Fe related defects.

scholarly journals I Like Vegetables: A Touch-and-Feel Board Book by L. Siminovich

2011 ◽  
Vol 1 (1) ◽  
Author(s):  
Kim Frail
Keyword(s):  
Cross Section ◽  
Public Services ◽  
Picture Book ◽  
The Other ◽  
Learning Method ◽  
University Of Alberta ◽  
Young Readers ◽  
Dinner Table ◽  
Wood Grain ◽  
The University

Siminovich, Lorena. I Like Vegetables: A Touch-and-Feel Board Book. Somerville: Candlewick Press, 2011. Print.“I Like Vegetables” is a dream come true for any nutritionally conscience parent, children’s librarian or teacher. The brightly hued collage illustrations are intriguingly textured with patterns and “touch & feel” inlays. Silky peas and rough-skinned carrots invite young readers to learn about vegetables. The layout is quite clever as it leverages contrast and comparison as a learning method. On one side of the page vegetables are depicted as they would appear growing in the garden while on the other side they are in the home being prepared for the dinner table. In addition, the nature side of the page illustrates the concept of opposites. For example, there are “tall” and “short” cornstalks. Orange carrot roots are “below” the ground, while the feathery green tops are “above”. The indoor side of the page features close-ups of vegetables against a wood-grain background that evokes a cutting board. Here children get a different perspective on the harvested veggies. We see shelled peas, open cornhusks and a cross-section of a pumpkin. The concluding series of images features an “empty” gardener’s basket next to a basket “full” of colourful vegetables on a blue and white gingham picnic tablecloth inlay.  This is primarily a picture book with only the names of the vegetables and the two opposing concepts appearing on each page. The typeset is Helvetica and is large and easy to read.  It is a sturdy board book and the inlays could not be easily ripped out or damaged. It is therefore a welcome addition to any toddler’s library. Other titles in the “I Like” series by Siminovich include: “I Like Toys “, “I Like Bugs” and “I Like Fruit”. “I Like Vegetables” is sure to engage children from ages 1-3. Highly recommended: 4 out of 4 stars Reviewer: Kim FrailKim is a Public Services Librarian at the H.T. Coutts Education Library at the University of Alberta. Children’s literature is a big part of her world at work and at home. She also enjoys gardening, renovating and keeping up with her two-year old. 

scholarly journals The iron-responsive genome of the chiton Acanthopleura granulata

2020 ◽  
Author(s):  
Rebecca M. Varney ◽  
Daniel I. Speiser ◽  
Carmel McDougall ◽  
Bernard M. Degnan ◽  
Kevin M. Kocot
Keyword(s):  
Iron Transport ◽  
West Indian ◽  
The Other ◽  
The West ◽  
Major Clade ◽  
Future Studies ◽  
Form And Function ◽  
Genetic Mechanisms ◽  
Molluscan Evolution ◽  
And Function

ABSTRACTMolluscs biomineralize structures that vary in composition, form, and function, prompting questions about the genetic mechanisms responsible for their production and the evolution of these mechanisms. Chitons (Mollusca, Polyplacophora) are a promising system for studies of biomineralization because they build a range of calcified structures including shell plates and spine- or scale-like sclerites. Chitons also harden the calcified teeth of their rasp-like radula with a coat of iron (as magnetite). Here we present the genome of the West Indian fuzzy chiton Acanthopleura granulata, the first from any aculiferan mollusc. The A. granulata genome contains homologs of many biomineralization genes identified previously in conchiferan molluscs. We expected chitons to lack genes previously identified from pathways conchiferans use to make biominerals like calcite and nacre because chitons do not use these materials in their shells. Surprisingly, the A. granulata genome has homologs of many of these genes, suggesting that the ancestral mollusc had a more diverse biomineralization toolkit than expected. The A. granulata genome has features that may be specialized for iron biomineralization, including a higher proportion of genes regulated directly by iron than other molluscs. A. granulata also produces two isoforms of soma-like ferritin: one is regulated by iron and similar in sequence to the soma-like ferritins of other molluscs, and the other is constitutively translated and is not found in other molluscs. The A. granulata genome is a resource for future studies of molluscan evolution and biomineralization.SIGNIFICANCE STATEMENTChitons are molluscs that make shell plates, spine- or scale-like sclerites, and iron-coated teeth. Currently, all molluscs with sequenced genomes lie within one major clade (Conchifera). Sequencing the genome of a representative from the other major clade (Aculifera) helps us learn about the origins and evolution of molluscan traits. The genome of the West Indian Fuzzy Chiton, Acanthopleura granulata, reveals chitons have homologs of many genes other molluscs use to make shells, suggesting all molluscs share some shell-making pathways. The genome of A. granulata has more genes that may be regulated directly by iron than other molluscs, and chitons produce a unique isoform of a major iron-transport protein (ferritin), suggesting that chitons have genomic specializations that contribute to their production of iron-coated teeth.

scholarly journals OBSERVATIONS ON THE FINE STRUCTURE OF THE DEVELOPING SPERMATID IN THE DOMESTIC CHICKEN

1962 ◽  
Vol 14 (2) ◽  
pp. 193-205 ◽  
Author(s):  
Toshio Nagano
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Cross Section ◽  
Neck Region ◽  
Structural Features ◽  
Dense Granule ◽  
Domestic Chicken ◽  
The Other ◽  
Dense Structure ◽  
Distal Centriole

The kinetic apparatus, the acrosome and associated structures, and the manchette of the spermatid of the domestic chicken have been studied with the electron microscope. The basic structural features of the two centrioles do not change during spermiogenesis, but there is a change in orientation and length. The proximal centriole is situated in a groove at the edge of the nucleus and oriented normal to the long axis of the nucleus and at right angles to the elongate distal centriole. The tail filaments appear to originate from the distal centriole. The plasma membrane is invaginated along the tail filaments. A dense structure which appears at the deep reflection of the plasma membrane is identified as the ring. The fine structure of the ring has no resemblance to that of a centriole and there is no evidence that it is derived from or related to the centrioles. The tail of the spermatid contains nine peripheral pairs and one central pair of tubular filaments. The two members of each pair of peripheral filaments differ in density and in shape: one is dense and circular, and the other is light and semilunar in cross-section. The dense filaments have processes. A manchette consisting of fine tubules appears in the cytoplasm of the older spermatid along the nucleus, neck region, and proximal segment of the tail. The acrosome is spherical in young spermatids and becomes crescentic and, finally, U-shaped as spermiogenesis proceeds. A dense granule is observed in the cytoplasm between acrosome and nucleus. This granule later becomes a dense rod which is interpreted as the perforatorium.

Habitat utilization by the arboreal boa Corallus grenadensis in two ecologically disparate habitats on Grenada

1998 ◽  
Vol 19 (2) ◽  
pp. 203-214 ◽  
Author(s):  
R. Allan Winstel ◽  
Richard A. Sajdak ◽  
Robert W. Henderson
Keyword(s):  
West Indian ◽  
Fruit Trees ◽  
Habitat Utilization ◽  
The Other ◽  
Medium Size ◽  
Agricultural Activity ◽  
Ontogenetic Shift ◽  
The West ◽  
Size Classes

AbstractHabitat utilization by the arboreal boid Corallus grenadensis was studied at two ecologically disparate sites on the West Indian island of Grenada: one devoted largely to agriculture, the other largely devoid of agricultural activity. Small snakes (< 600 mm SVL) were most often encountered in uncultivated scrub woodland at both sites; large snakes (>1100 mm SVL) were encountered most often in fruit trees at one site and in mangroves at the other. Snakes of medium size (600-1100 mm SVL) occurred in both kinds of habitat. These size classes correspond to an ontogenetic shift in diet (lizards to mammals), and this is associated with a corresponding shift in habitat utilization.

scholarly journals On Measuring Section Thickness

2001 ◽  
Vol 9 (4) ◽  
pp. 17-17
Author(s):  
Ron Doole
Keyword(s):  
Film Thickness ◽  
Cross Section ◽  
Accurate Result ◽  
The Other ◽  
Section Thickness ◽  
Plan View ◽  
Tilt Axis ◽  
Measuring Section ◽  
Easy Case

Section thickness can be measured by placing beads of some kind on the top and bottom surfaces of the section. This is then a simple parallax problem.Imagine the specimen in cross section. If there are two particles, one vertically above the other they are separated by the film thickness T. Tilt the film through an angle A and in plan view the particles will separate by a distance D. This can also be extended to account for two particles not vertically above each other but I'll stick to the easy case for the explanation.Take two negatives one at zero tilt and one at tilt of A and measure the separation D. The thickness can be calculated by T=D/sinA.The direction of the tilt axis must be known for the measurements and it is easy to see that the larger the tiit angle and the more accurately the separation is measured, the more accurate the measurement will be. Tilt at both positive and negative angles to get a more accurate result.

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