The optimal shape of avian eggs

Measuring steroid hormones in avian eggs.

Avian eggs contain substantial levels of various hormones of maternal origin and have recently received a lot of interest, mainly from behavioral ecologists. These studies strongly depend on the measurement of egg hormone levels, but the method of measuring these levels has received little attention. This paper describes the sampling, extraction, and assay of hormones in avian eggs and related ...

The optimal shape of roots

Roots provide plants with mechanical stability and pure water. Wind and gravitational forces on plants are spread out by the roots over a large volume of soil. In a similar manner, roots absorb pure water and nutrients from moist soil. These processes are mathematically similar and have similar optimal solutions, unless the soil is inhomogeneous -i.e. if one part is wetter, whereas another part...

Avian eggs: thermoregulatory value of very high near-infrared reflectance.

Studies of the spectral reflectance of the eggs of 25 species of birds from nine families disclosed uniformly high reflectance (often above 90 percent) in the near infrared. This property is associated with the presence of the eggshell pigments protoporphyrin and the bilins. These pigments allow coloration for cryptic or other purposes with minimum solar heating, a combination not possible with...

Shape-Measure Method for Solving Elliptic Optimal Shape Problems (Fixed Control Case)

Embryonic growth and antioxidant provision in avian eggs.

Avian embryos undergo extremely rapid development over a relatively short period of time, and so are likely to suffer high levels of oxidative damage unless this is mitigated by sufficient maternal allocation of appropriate antioxidants. At a species level, it is therefore predicted that antioxidants should be allocated to eggs according to the rate of embryonic growth, such that eggs containin...