scholarly journals A Histochemical Study of the Organic Matrix of Hen Egg-Shells

1957 ◽  
Vol s3-98 (41) ◽  
pp. 19-28
Author(s):  
K. SIMKISS ◽  
C. TYLER

A study of the organic material of the hen egg-shell has been made by the use of recognized histochemical techniques. It has been found that, in the so-called spongy layer of the shell, the organic matrix consists of a protein / acid mucopolysaccharide complex. The organic material of the mammillary layer appears to be more concentrated in a central core, and is somewhat different in that it contains fat and a reducing substance. The protein / acid mucopolysaccharide complex is a collagen-like material, but is probably not collagen itself because the protein portion is low in hydroxyproline and the acid mucopolysaccharide is most likely mucoitin and not chondroitin sulphuric acid. The results are discussed in relation to shell calcification and it is suggested that the protein / acid mucopolysaccharide complex is first firmly attached to the keratin of the membrane, but once this is accomplished it links on to material of its own kind. Calcification proceeds simultaneously, but near the points of contact with the membrane (i.e. in the core of each mammilla) calcification is not so intense as it is in the rest of the shell.

1959 ◽  
Vol s3-100 (52) ◽  
pp. 529-538
Author(s):  
K. SIMKISS ◽  
C. TYLER

Studies have been made of the organic matrix of certain reptilian egg-shells. The interaction between egg-shell-matrix and various metal ions has been considered by noting the effect of these ions on the staining of the matrix by toluidine blue. A comparison of the results with those for the hen indicates that the chelating mechanism in the Chelonia is similar to that in the hen, but that that in the Crocodilia is different. It is suggested that in the Crocodilia the acid mucopolysaccharide of the matrix is embedded in, but not combined with, the protein and that its chelating mechanism is carboxylate group to carboxylate group, while in the hen and Chelonia, the acid mucopolysaccharide is combined with the protein and that its chelating mechanism is carboxylate group to amino group.


2016 ◽  
Vol 41 (2) ◽  
pp. 67-72
Author(s):  
Jannatul Fardous ◽  
S.M Shamsuzzaman

This study was done to identify different pathogenic aerobic bacteria from egg shell and egg contents of hen. Egg shells and egg contents of 150 eggs collected from poultry were tested. Of 150 egg shells, 130 (86.67%) yielded growth of bacteria and 60 (40%) Esch. coli, 25 (16.67%) Providencia rettgeri, 5 (3.33%) Providencia alkalifaciens, 20 (13.33%) Citrobacter freundii, 10 (6.67%) Salmonella spp, 10 (6.67%) Enterobacter aerogenes were isolated. No bacteria were isolated from 150 egg contents. Total 14 (9.33%) Salmonella spp. from egg shells and 7 (4.67%) Salmonella spp. from egg contents were identified by PCR. Most of the identified serotypes were Salmonella Enteritidis (42.86% from egg shells and 71.43% from egg contents). All (100%) Salmonella Typhi and Salmonella Paratyphi A were sensitive to ciprofloxacin and ceftriaxone.


1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 922-929 ◽  
Author(s):  
M.U. Nylen

The literature on the ultrastructural morphology of the enamel matrix and its relationship to the crystals is reviewed. Two morphological entities of the matrix are discussed: One is the so-called stippled material which may be the initial cell product; the other, variously described as fibrillar, lamellar, tubular or helical, is thought by many to play a crucial role in nucleation and orientation of the crystals. A number of observations, however, suggest that the latter structures form secondarily to the crystals and that in reality they represent organic material adsorbed to the crystal surface and maintained as independent structures upon removal of the mineral. The need for additional studies is stressed including systematic studies of interactions between constituents of the organic matrix and the apatite crystals.


1882 ◽  
Vol 14 (3) ◽  
pp. 49-56
Author(s):  
W. H. Edwards
Keyword(s):  
New Born ◽  

8. On Young Caterpillars Eating their Egg Shells.Mr. Scudder, Butterflies, p. 101, says, after describing the way in which the caterpillar eats out of the egg: “The taste he has gained of egg-shell seems to allure him; for, strange as it may seem, although placed by the provident parent within immediate reach of choice and succulent food, he will not taste it until he has devoured the last remmant of his prison-walls. Strange food this for a new born babe! The act, however, is plainly a provision of nature by which the tender animal is rid of a sure token to his enemies of his immediate proximity.” Surely here is an error in fact, and a wrong conclusion whatever the fact may be. I read the above statement on the 25th July last, and at once went to my garden to search for eggs of Libythea Bachmanni, on Hackberry leaves. The young caterpillars of this species are green, of a shade so near that of the leaves they feed on, that it is very difficult to discover them. Even where the tip of the leaf has been eaten, and their presence is suspected, it is easy to overlook them. I found at once three eggs and one young caterpillar. The egg from which this caterpillar had come was present at the base of the leaf on the extreme tip of which the little creature rested. A hole was in its side near the top, and no more had been eaten than just enough to permit egress.


2018 ◽  
Vol 192 ◽  
pp. 03006
Author(s):  
Jakkrapong Jitjamnong

The purpose of this research was to investigate the catalytic activity of Ba loading on calcium oxide (CaO) catalyst by varying the amount of barium added during the synthesis: 5-15 wt%. The waste egg shells were utilized as a CaO heterogeneous catalyst by calcined at 900 °C for 2 h. The Ba/CaO catalysts were prepared by impregnation method and were used as a catalyst in transesterification reaction of canola oil via microwave irradiation under microwave power 300 W. The characterization of catalyst and FAME composition of biodiesel were determined by X-ray fluorescence (XRF), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), and gas chromatography (GC-FID). The conditions of biodiesel production were operated at 60 °C, 3 wt% of catalyst loading, 9:1 methanol-to-canola oil ratio, and microwave irradiation power was 300W for 2 min. The experimental results found that, the waste egg shells consist mainly of CaCO3, which was decomposed to CaO more than 88 wt% after cacination step. The 15 wt% Ba/CaO catalysts exhibited the best catalytic performance with the FAME conversion higher than 97.68%.


1950 ◽  
Vol s3-91 (14) ◽  
pp. 195-203
Author(s):  
A. MOSCONA

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.


2019 ◽  
Vol 817 ◽  
pp. 421-426
Author(s):  
Mahdi Ghaemi ◽  
Angelo Di Tommaso ◽  
Cristina Gentilini

In the present study, a series of pull-off tests is performed to determine the bonding properties of fiber reinforced polymer (FRP) composites applied to a brittle substrate. Pull-off test is simple, fast and cheap and it is generally employed to evaluate the bond strength between the composite and the substrate. It is a procedure that can be easily performed on-site for checking the quality of the reinforcement adhesion.A steel composite made of a unidirectional steel fabric embedded in an organic matrix (bi-component epoxy resin) was applied to the surface of fired-clay bricks. A shallow core perpendicular to the surface was realized in the test specimen, leaving the core attached to the brick. A steel dolly was glued to the external surface of the core using epoxy adhesive. A loading device was employed to apply the tensile force until failure. The effects of moisture presence on the substrate and shape of the cores on the pull-off strength were investigated.


Parasitology ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 103-113 ◽  
Author(s):  
D. A. Wharton

SUMMARYThe egg-shell of Hammerschmidtiella diesingi and Aspiculuris tetraptera reduces the rate of water loss from the egg when exposed to desiccation. Staining of the enclosed larva by acid fuchsin and the collapse of eggs exposed to desiccation indicate that the permeability barrier is heat labile. This suggests that the lipid layer is the main permeability barrie of the shell. The complex structure of the uterine layers has a similar morphology to the respiratory structures of the chorion of some insect eggs. Reflections from the shell, the rate of embryonic development under various conditions and the penetration of lead ions indicate that the shell does not trap a layer of air when immersed in water and the uterine layers cannot, therefore, function as a plastron network. Calculations indicate that if diffusion is limited to the pores in the external uterine layer, the area available for gaseous exchange is reduced by 85·5% in H. diesingi, 95·6% in A. tetraptera and 96·8% in Syphacia obvelata. It is suggested that the uterine layers of oxyurid egg-shells function in a similar fashion to the pores in bird egg-shells and the aeropyles in the chorion of insect egg-shells which do not possess plastron networks. These structures reduce water loss from the egg whilst ensuring an adequate supply of oxygen for embryonic development.


Parasitology ◽  
1976 ◽  
Vol 72 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Alan F. Bird ◽  
M. A. McClure

SummaryThe fine structure of egg shells of four different genera belonging to the order Tylenchida has been examined. The species examined were Meloidogyne javanica, Rotylenchulus reniformis, Tylenchulus semipenetrans and Pratylenchus minyus. They are all similar in their basic structure, being composed of vitelline membrane, chitin and lipid layers, but there is considerable variability in the thickness of these layers.We have retained the conventional nomenclature because of its convenience, but it is clear that these layers have a variety of chemical components. However, they do appear to contain the compounds from which they take their name. Thus chitin occurs in the chitin layer, and lipid in the lipid layer. The latter is removed by the technique used in isolating the shell from the egg. Chemical analysis of the hydrolysis products of these shells has revealed a high (35 %) proline content which appears to be a characteristic of those nematode egg shells which have been examined so far. These analyses and treatment with enzymes indicate that the chitin layer is a chitin–protein complex.Experiments on the permeability of eggs of M. javanica at different temperatures indicate that changes in permeability are not due to the melting of a single lipid with a distinct melting point as had been thought in the past. We have found that Arrhenius activation energies calculated from the two slopes of an Arrhenius plot were 17·8 kcal/mol and 43·0 kcal/mol respectively, the transition from one to the other taking place at 62°C. We think that these changes are due to changes in the properties of lipoprotein membranes in the lipid layer. These membranes appear to be of paramount importance in controlling the permeability of the nematode egg shell.


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