نتایج جستجو برای: eggshells
تعداد نتایج: 593 فیلتر نتایج به سال:
Mosquito vectors lay their white eggs in the aquatic milieu. During early embryogenesis water passes freely through the transparent eggshell, which at this moment is composed of exochorion and endochorion. Within two hours the endochorion darkens via melanization but even so eggs shrink and perish if removed from moisture. However, during mid-embryogenesis, cells of the extraembryonic serosa se...
BACKGROUND We describe the first occurrence in the fossil record of an aquatic avian twig-nest with five eggs in situ (Early Miocene Tudela Formation, Ebro Basin, Spain). Extensive outcrops of this formation reveal autochthonous avian osteological and oological fossils that represent a single taxon identified as a basal phoenicopterid. Although the eggshell structure is definitively phoenicopte...
We compared eggshell thickness of hatched eggs with that of non-developed eggs in endangered falcon taxa to explore the effect of embryo development on eggshell thinning. To our knowledge, this has never been examined before in falcons, despite the fact that eggshell thinning due to pollutants and environmental contamination is often considered the most common cause of egg failure in falcons. B...
A 2 × 2 factorial design experiment examined the effect of dietary non-phytate phosphorus (NPP) (1.3 and 4.0 g/kg) and 3-phytase (F) (0 and 150 FTU/kg) on the performance indicators of hens, physical parameters of eggs, phosphorus (P) content of the eggshells, and the pH of the digestive tract of laying hens. Two hundred and forty hens (ISA Brown) were housed in enriched cages and fed a wheat-m...
BACKGROUND Schistosoma mansoni and Schistosoma japonicum are the most frequent causative agents of human intestinal schistosomiasis. Approximately 200 million people in the world are infected with schistosomes. Diagnosis of schistosomiasis is often difficult. High percentages of low level infections are missed in routine fecal smear analysis and current diagnostic methodologies are inadequate t...
The viability of freshly laid avian eggs declines after several days of exposure to ambient temperatures above physiological zero, and declines occur faster in tropical than temperate ecosystems. Microbial infection during preincubation exposure has recently been shown as a second cause of egg viability decline in the tropics, but whether microbial processes influence the viability of wild bird...
Abstract The use of materials natural origin for the adsorption heavy metal ions from aqueous solutions has gained attention in recent years among scientific community. This is explained by fact that nickel compounds, due to severe health consequences, are considered be most dangerous environment. article reviews results studies on biosorbents purification ions, and then attempts classify them ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید