The total bone cross-sectional area (mm), bone medullary area (mm), and cortical thickness (mm) were also measured.
The residual hole cross-sectional area (mm) was quantified at the top of the hole and at three different depths (0.5 mm, 1.0 mm and 1.5 mm) from the top of the hole using a polygon tool (CTAn software, Skyscan, Kontich, Belgium) to draw a 2D region of interest in the axial plane that circumscribed the non-mineralized hole edge (Additional file 1: Figure S1A).
The resulting images were then analysed using Image J (available at: http://rsb.info.nih.gov/ij/) and the size of each egg was measured as a cross-sectional projection (mm).
We determined the following parameters: (1) the LV number (LVN), (2) the area covered by LVs (LVA), (3) the LV density (LVD), determined by measuring the LVN and dividing it by the tumour cross-sectional area (mm).
Pararge aegeria eggs are spherical, and the size of each egg could therefore be measured as a cross-sectional projection (mm) using a digital camera (Canon A720 IS, Canon Ltd., Reigate, UK).
To analyze the carotid remodeling, carotid cross-sectional area (mm) was calculated according to the formula: [ π × [(2 × IMT + D /2] − π × (D/2)] as a surrogate for carotid arterial mass, where D represents the internal diameter of the common carotid artery.
In the tensile strength test, the tendons were stretched at a set strain rate of 0.08/s [with strain measured as (l− lo)/ lo, where l is the length of the sample, and lo the original sample length] until breaking point, and a stress/strain curve was plotted [stress being the F/csa, where F is the force (N), and csa the cross-sectional area (mm)] (Table 1 and Fig. 6A).
The laboratory measurements ((mu _{mathrm{i}}=10000), length (=200) mm, cross-sectional area (=5times 5) mm, and gap (=18, 25), and 28 mm) are added for reference.
Measurements from the mid-femur and proximal tibia included bone periosteal circumference (mm), cortical cross-sectional area (CSA, mm), cortical attenuation (HU), mean cortical thickness (mm), maximum and minimum cortical cross-sectional moment of inertia weighted by HU (CSMI, HU cm), and muscle CSA (mm).
For the shaft regions (66%), the analyzed bone traits were cortical bone mineral density (CrtBMD, mg/cm), cortical bone area (CBA, mm), muscle cross-sectional area (MuscleCSA, mm), fat cross-sectional area (FatCSA, cm), and density-weighted polar section modulus (SSIp, mm, an estimate of bending and torsional bone strength for cortical bone).
