Fractal analysis of extra‐embryonic vascularization in Japanese quail embryos exposed to extremely low frequency magnetic fields

Abstract

Magnetic fields (MF) can alter the dynamic behavior of vascular tissue and may have a stimulatory or inhibitory effect on blood vessel growth. Fractal geometry has been used in several studies as a tool to describe the development of blood vascular networks. Due to its self-similarity, irregularity, fractional dimension, and dependence on the scale of vessel dimensions, vascular networks can be taken as fractal objects. In this work, we calculated the fractal dimension by the methods of box counting (D(bc)) and information dimension (D(inf)) to evaluate the development of blood vessels of the yolk sac membrane (YSM) from quail embryos exposed to MF with a magnetic flux density of 1 mT and a frequency of 60 Hz. The obtained results showed that when the MF was applied to embryos aged between 48 and 72 h, in sessions of 2 h (6 h/day) and 3 h (9 h/day) with exposure intervals between 6 and 5 h, respectively, blood vascular formation was inhibited. Exposure sessions shorter than 2 h or longer than 3 h had no observable change on the vascular process. In contrast, the magnetic field had no observable change on the YSM vascular network for embryos aged between 72 and 96 h, irrespective of the exposure time. In conclusion, these results show a "window effect" regarding exposure time.

Fractal, multifractal and lacunarity analysis applied in retinal regionsof diabetic patients with and without non-proliferative diabetic retinopathy

“…For the box-counting dimension (D bc ), the skeletonized image was covered with a number of boxes (N (r)) containing at least one pixel of the image. The procedure was repeated with boxes of different sizes and plotted in a double log graph of N (r) in relation to the sides of boxes r [21]. The slope of this relationship with inverted signal is the box-counting dimension:…”

“…N is the number of boxes, m i = M i /M, and M i is the number of pixels in the n th box, M is the total number of pixels on the fractal object, r is the side of boxes and ε is a infinitesimal variation in box sizes [21]. The calculations of D inf used 8 sets of different size boxes, the length of the largest box side being 270 pixels and the reduction coefficient of box size 2.0.…”

High Glucose Level Induces Cardiovascular Dysplasia During Early Embryo Development

“…There is no doubt that actors that causes angiodysplasia will result in embryonic dysplasia and death of the embryos. It has been proposed that vascular diseases could be predicated from measurement of the dimension of the blood vessels and density of the vasculature [15].…”

“…During development, the chorionic membrane and allantois fuses together to form the CAM. The YSM model is an adequate model for studying blood vessel formation [15] but the CAM model also possesses many advantages because it is highly vascular, highly reproducible, simplistic and low-cost. In addition, as the CAM assay is a closed system, it makes small molecules, peptides and drugs under study more stable [16].…”

Extremely low-frequency magnetic fields can impair spermatogenesis recovery after reversible testicular damage induced by heat

“…The induced electric field was obtained as previously described by Costa et al (2013). Helmholtz coils of radius R ¼ 19 cm and number of turns N ¼ 154 connected in parallel and fed by an alternating current I (t) ¼ I 0 sin(!t) generate a magnetic field given by:…”