Search results for "Egg Shell"
showing 6 items of 6 documents
Eggshell types and their evolutionary correlation with life-history strategies in squamates
2015
The eggshell is an important physiological structure for the embryo. It enables gas exchange, physical protection and is a calcium reserve. Most squamates (lizards, snakes, worm lizards) lay parchment-shelled eggs, whereas only some gekkotan species, a subgroup of lizards, have strongly calcified eggshells. In viviparous (live-bearing) squamates the eggshell is reduced or completely missing (hereafter “shell-less”). Recent studies showed that life-history strategies of gekkotan species differ between species with parchment- and rigid-shelled eggshells. Here we test if the three different eggshell types found in the squamates are also associated with different life-history strategies. We fir…
Zastosowanie skorup jaj do usuwania metali ciężkich ze ścieków z instalacji odsiarczania spalin
2018
Przeprowadzono badania skuteczności usuwania kationów Ni, Cu i Cd z roztworów wodnych z zastosowaniem wapienia marglistego, skorup jaj kurzych przeznaczonych do konsumpcji oraz skorup jaj kurzych po wylęgu, których głównym składnikiem jest węglan wapnia. Skorupy jaj kurzych są produktem ubocznym przemysłu spożywczego, który może znaleźć zastosowanie jako zamiennik wapienia marglistego wykorzystywanego do usuwania metali ciężkich z instalacji mokrego odsiarczania spalin. Do badań użyto mieszanych roztworów Ni, Cu i Cd składem zbliżonych do ścieków z instalacji mokrego odsiarczania spalin: Ni (0,526-3,118 mg/dm3 ), Cu (0,483-4,285 mg/dm3 ) i Cd (0,372-0,875 mg/dm3 ). Metale oznaczano metodą a…
Optical illusions in scanning electron micrographs: the case of the eggshell of Acrosternum (Chinavia) marginatum (Hemiptera: Pentatomidae)
2003
Scanning electron microscopy revealed that-as is common in this family of the Hemiptera-the eggs of the green stink bug Acrosternum (Chinavia) marginatum are roughly barrel-shaped and possess at their apical pole a row of slender extensions, the aero-micropylar processes. The outer surface of the eggshell carries hexagonally arranged pits. The analysis of cross-fractured eggshells showed that the pits have slender basal extensions with transverse diaphragms. When scanning electron micrographs of the egg surface of A. marginatum are viewed upside down, the perception flips and the pits appear as elevations to all observers addressed. Thus, we are dealing with an optical illusion, which is kn…
Comment on "Ecological importance of the thermal emissivity of avian eggshells".
2012
Eggshell emissivity must be known to determine accurately the cooling rate of avian eggs when the parent, after heating by conduction during the incubation, is temporarily absent. We estimate possible values of eggshell emissivities from in-situ measurements and spectral libraries. Emissivity is near to 1 (probably higher than 0.95) and therefore its effect on cooling rate may be negligible, with differences between the temperature of the egg assuming a value of e=0.95 and that of a blackbody (e=1) below 0.2 °C.
Strong stabilization of amorphous calcium carbonate emulsion by ovalbumin: gaining insight into the mechanism of 'polymer-induced liquid precursor' p…
2011
8 pages; International audience; The impact of the ovo proteins ovalbumin and lysozyme-present in the first stage of egg shell formation-on the homogeneous formation of the liquid amorphous calcium carbonate (LACC) precursor, was studied by a combination of complementing methods: in situ WAXS, SANS, XANES, TEM, and immunogold labeling. Lysozyme (pI = 9.3) destabilizes the LACC emulsion whereas the glycoprotein ovalbumin (pI = 4.7) extends the lifespan of the emulsified state remarkably. In the light of the presented data: (a) Ovalbumin is shown to behave commensurable to the 'polymer-induced liquid precursor' (PILP) process proposed by Gower et al. Ovalbumin can be assumed to take a key rol…
Assessment of Salmonella spp. in feces, cloacal swabs, and eggs (eggshell and content separately) from a laying hen farm.
2011
Microbial pathogens of the genus Salmonella are among the leading causes of foodborne illness in the world. The present study was done on a laying hen farm with a Salmonella enterica serovar Enteritidis-positive result according to the testing specified by European regulation 2160/2003. The aim of this study was to compare the Salmonella contamination on a laying hen farm with the Salmonella presence in the hen eggs. The strains were isolated by ISO method 6579:2002 (standard method for the detection of Salmonella spp. in the European regulation for food and animal feeding stuffs, animal feces, and environmental samples from the primary production stage, including poultry farms) and were co…