Radiographic Studies on the Formation of the Hen'S Egg Shell

1951 ◽  
Vol 28 (2) ◽  
pp. 125-140
Author(s):  
J. R. G. BRADFIELD
Keyword(s):  
Calcium Carbonate ◽  
Mineral Matter ◽  
Carbonate Content ◽  
Shell Gland ◽  
X Rays ◽  
Characteristic Structure ◽  
Hen’S Egg ◽  
Shell Deposition ◽  
Egg Shell ◽  
Pointed End

1. Radiographic methods have been used to study the rate of deposition of the hen's egg shell and the changes in volume and orientation undergone by the egg in the shell gland. 2. Shell deposition commences about 5 hr. after the yolk is ovulated and several series of radiographs were obtained tracing the process from these earliest stages through to the fully calcined shell. 3. From radiographs of calcium carbonate-gelatin mixtures it was found that, for a series of comparable objects differing only in calcium carbonate content, the densitometer readings on their radiographs were directly proportional to the density of calcium carbonate traversed by the X-rays in each object. 4. Hence, densitometer measurements on the periphery of the shell in each of a series of radiographs taken during the development of a single egg shell give values which are proportional to the density (or thickness) of calcium carbonate traversed by the tangential rays. It is shown that the radial thickness is closely proportional to the square of these values. 5. Plotting these squared densitometer readings against time indicates that the rate of deposition of mineral matter in the shell follows an S-shaped curve, with a marked acceleration in shell deposition 5-6 hr. after its onset. 6. During its first few hours in the shell gland, the egg undergoes a 25% osmotic increase in volume. This swelling is brought to a fairly abrupt halt by the increase in the rate of shell deposition and the consequent increase in the impermeability and rigidity of the shell. 7. Throughout all but the last hour or two of its 20 hr. stay in the shell gland, the egg lies with its pointed end caudal. Shortly before it is laid, however, it usually undergoes a 180° rotation in a horizontal plane. Thus the blunt end finally becomes caudal and emerges first when the egg is laid. During the rotation, the egg sinks to a more ventral position. This is necessary because, in most hens, the length of the egg plus the thickness of the walls of the shell gland is greater than the width of the pelvis. 8. The possible significance of the S-shaped curve of shell deposition is discussed. The volume, shape and orientation of the egg are considered in relation to the needs of the chick embryo and to the characteristic structure of the bird's oviduct and pelvis.

scholarly journals Studies on the Organic Components of Shell Gland Fluid and the Hen's Egg Shell

1980 ◽  
Vol 59 (2) ◽  
pp. 438-443 ◽  
Author(s):  
EDWARD SALEVSKY ◽  
R.M. LEACH
Keyword(s):  
Shell Gland ◽  
Organic Components ◽  
Hen’S Egg ◽  
Egg Shell

scholarly journals Opto‐electrochemical Dissolution Reveals Coccolith Calcium Carbonate Content

2021 ◽  
Author(s):  
Minjun Yang ◽  
Christopher Batchelor-McAuley ◽  
Samuel Barton ◽  
Rosalind E.M. Rickaby ◽  
Heather A. Bouman ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Carbonate Content ◽  
Electrochemical Dissolution ◽  
Calcium Carbonate Content

scholarly journals A Novel Resorbable Composite Material Containing Poly(ester-co-urethane) and Precipitated Calcium Carbonate Spherulites for Bone Augmentation—Development and Preclinical Pilot Trials

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 102
Author(s):  
Claudia Rode ◽  
Ralf Wyrwa ◽  
Juergen Weisser ◽  
Matthias Schnabelrauch ◽  
Marijan Vučak ◽  
...  
Keyword(s):  
Composite Material ◽  
Calcium Carbonate ◽  
Bone Substitute ◽  
Pilot Trial ◽  
Carbonate Content ◽  
Precipitated Calcium Carbonate ◽  
Degradation Behaviour ◽  
Biodegradable Composite ◽  
Loss Of Mass

Polyurethanes have the potential to impart cell-relevant properties like excellent biocompatibility, high and interconnecting porosity and controlled degradability into biomaterials in a relatively simple way. In this context, a biodegradable composite material made of an isocyanate-terminated co-oligoester prepolymer and precipitated calcium carbonated spherulites (up to 60% w/w) was synthesized and investigated with regard to an application as bone substitute in dental and orthodontic application. After foaming the composite material, a predominantly interconnecting porous structure is obtained, which can be easily machined. The compressive strength of the foamed composites increases with raising calcium carbonate content and decreasing calcium carbonate particle size. When stored in an aqueous medium, there is a decrease in pressure stability of the composite, but this decrease is smaller the higher the proportion of the calcium carbonate component is. In vitro cytocompatibility studies of the foamed composites on MC3T3-E1 pre-osteoblasts revealed an excellent cytocompatibility. The in vitro degradation behaviour of foamed composite is characterised by a continuous loss of mass, which is slower with higher calcium carbonate contents. In a first pre-clinical pilot trial the foamed composite bone substitute material (fcm) was successfully evaluated in a model of vertical augmentation in an established animal model on the calvaria and on the lateral mandible of pigs.

FRAGMENT OR BROKEN? IMPROVING THE PLANKTONIC FORAMINIFERA FRAGMENTATION ASSESSMENT

Palaios ◽  
2021 ◽  
Vol 36 (5) ◽  
pp. 165-172
Author(s):  
JAIME YESID SUÁREZ-IBARRA ◽  
CRISTIANE FRAGA FROZZA ◽  
SANDRO MONTICELLI PETRÓ ◽  
MARIA ALEJANDRA GÓMEZ PIVEL
Keyword(s):  
Weight Loss ◽  
Calcium Carbonate ◽  
Planktonic Foraminifera ◽  
Carbonate Content ◽  
Sand Content ◽  
Future Studies ◽  
Software Analysis ◽  
Fragmentation Index ◽  
Area And Perimeter ◽  
Partial Damage

ABSTRACT Planktonic foraminifera tests can suffer dissolution, which usually involves partial damage, weight loss, and fragmentation. Since planktonic foraminifera assemblages, consisting of different resistant/susceptible species, can be strongly modified by dissolution, it is imperative to quantify its effect. The fragmentation index proposed 50 years ago has been used widely to measure preservation of planktonic foraminifera tests, but calibrations to this method are necessary. Some revisions are based on assumptions, like a certain number of fragments produced by a unique test, which is then used to compare whole tests with the dissolution remains. Likewise, researchers do not agree on what they count and how they identify what they count. Here we present a standardized and less subjective method, called fragmentation intensity (FI), to better assess the fragmentation of planktonic foraminifera through image software analysis, which includes both fragmentation remains (fragments and broken tests) and their measured area and perimeter. When compared to calcium carbonate content, grain sand content, and planktonic foraminifera tests per gram of dry sediment, the FI method derived better correlation values than the broken and fragments indexes. Future studies, in varying oceanographic contexts, can test this method to improve confidence, and eventually possibly adapt the index into a proxy for calcium carbonate undersaturation.

scholarly journals Classification of brown earths based on field and laboratory properties: Problematic issues and proposition of their solution

2019 ◽  
Vol 52 (2) ◽  
pp. 225
Author(s):  
Karolina Woźnica ◽  
Agnieszka Józefowska ◽  
Justyna Sokołowska ◽  
Ryszard Mazurek ◽  
Tomasz Zaleski
Keyword(s):  
Calcium Carbonate ◽  
Main Parameter ◽  
Ph Value ◽  
Soil Classification ◽  
Base Saturation ◽  
Carbonate Content ◽  
Field Guide ◽  
Content Determination

<p class="Default">In this paper, the current problems associated with the classification of brown earths, are presented. According to the Polish Soil Classification (PSC) (1989, 2011), base saturation is the main parameter for identifying eutrophic and dystrophic brown soils. In practice, however, it is not possible to determine the base saturation value in the field. Therefore, the aim of this study was to estimate the base saturation using a regression equation and create a field guide for brown earths, based on the pH value, measured using a Hellige indicator, and the calcium carbonate content. Determination of the pH ranges enabled the classification of brown earth types in the field. These results suggest that pH can be used as a proxy for base saturation especially in the field. A change in the hierarchy of soil (sub)types is proposed for the new Polish Soil Classification.</p>

Studies of the Egg of Bacillus libanicus (Orthoptera, Phasmidae)

1950 ◽  
Vol s3-91 (14) ◽  
pp. 195-203
Author(s):  
A. MOSCONA
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Embryonic Development ◽  
Moisture Content ◽  
Mineral Content ◽  
Calcium Deficiency ◽  
Egg Shells ◽  
Egg Shell ◽  
Short Time ◽  
Initial Mineral

1. Weight, moisture content, and mineral content of freshly laid and of fully developed eggs of Bacillus libanicus (Uv.) were studied. During development of the embryo the egg-shell loses 19 per cent, of its initial mineral content, while the weight of mineral materials in the embryo increases correspondingly. 2. These changes can be explained only as resulting from transfer of minerals from the shell to the embryo. The mineral materials are derived from the calcium carbonate layer of the shell, which, owing to this loss, becomes thinner during embryonic development. 3. It is suggested that the mechanism of this transfer is based on the production of bicarbonate by the reaction of water and carbon dioxide, given off by the embryo, with the calcium carbonate of the shell. 4. Experimental calcium deficiency in the egg-shells results in a marked lowering of the viability of the embryos; although embryogenesis may sometimes proceed till the hatching stage, the few emerging nymphs survive only for a short time. 5. The possible occurrence of mineral transfer in other phasmid eggs is indicated.

Studies in the absorption and excretion of certain minerals by poultry. III. The influence of different levels of dietary calcium upon the retention of calcium, phosphorus, carbonate and chloride

1946 ◽  
Vol 36 (4) ◽  
pp. 283-288 ◽  
Author(s):  
Cyril Tyler
Keyword(s):  
Calcium Carbonate ◽  
Dietary Calcium ◽  
Egg Laying ◽  
Carbonate Content ◽  
Phosphorus Excretion ◽  
Calcium Carbonate Content ◽  
High Calcium ◽  
Calcium Phosphorus ◽  
Different Levels

1. The daily retention of calcium, carbonate, phosphorus and chloride was studied using four birds and changing the calcium carbonate content of the ration every 5 days for 15 days.2. It was shown that high calcium diets result in a much lower retention of calcium and thin-shelled eggs are produced.3. Retention of calcium was higher in the laying than in the non-laying bird when calcium carbonate was fed.4. High calcium diets depressed the retention of phosphorus, and in one case the retention was negative, even when no eggs were laid. Laying birds gave negative values for retention because of the heavy phosphorus excretion associated with egg laying.5. High calcium diets also depressed the retention of chloride, and on occasion led to negative retention values.

Oriented Crystallization of Urea in Membranes

1965 ◽  
Vol 9 ◽  
pp. 190-193
Author(s):  
Edwin H. Shaw
Keyword(s):  
Urea Solution ◽  
Fiber Axis ◽  
X Rays ◽  
Renal Capsule ◽  
Shell Membrane ◽  
Renal Fascia ◽  
Egg Shell Membrane ◽  
Egg Shell ◽  
Half Axis ◽  
The Right

AbstractInner egg shell membrane was soaked in 2 M urea solution and dried. Cu Kα X-rays directed perpendular to the membrane yielded an urtsymmetrical diffraction pattern with urea 110, 111, 102, 210 and 211 planes diffracting to the right and urea 101, 200 and 201 planes diffracting to the left. The urea appears to be hydrogenbonded diagonally between the lamellae of β-keratin at an angle of 33.5° to the 6.68 Å b-axis (fiber axis) of the parallel pleated sheet structure, shortening the half-axis lengths in the a direction from 4.73 Å to 4.41 Å. Similar results were obtained with formalinized dog mesentery. Keratinous outer egg shell membrane, formal in bed collagenous dog renal capsule, formslinized collagenous pheasant pericardium, and formalinized callogenous human arachnoid yielded symmetrically oriented urea layer lines. Formalinized dog renal fascia and pleura yielded random urea lines.

ULTRASTRUCTURE OF THE HEN'S EGG SHELL MEMBRANES BY ELECTRON MICROSCOPY

1972 ◽  
Vol 37 (2) ◽  
pp. 277-281 ◽  
Author(s):  
M. A. TUNG ◽  
J. F. RICHARDS
Keyword(s):  
Electron Microscopy ◽  
Hen’S Egg ◽  
Egg Shell
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