Multifractal detrended fluctuation analysis to characterize phase couplings in seahorse (Hippocampus kuda) feeding clicks.

Nonlinear phenomena in animal vocalizations fundamentally includes known features, namely, frequency jump, subharmonics, biphonation, and deterministic chaos. In the present study, the multifractal detrended fluctuation analysis (MFDFA) has been employed to characterize the phase couplings revealed in the feeding clicks of Hippocampus kuda yellow seahorse. The fluctuation function Fq(s), generalized Hurst exponent h(q), multifractal scaling exponent τ(q), and the multifractal spectrum f(α) calculated in the procedure followed were analyzed to comprehend the underlying nonlinearities in the seahorse clicks. The analyses carried out reveal long-range power-law correlation properties in the data, substantiating the multifractal behavior. The resulting h(q) spectrum exhibits a distinct characteristic pattern in relation to the seahorse sex and size, and reveals a spectral blind spot in the data that was not possible to detect by conventional spectral analyses. The corresponding multifractal spectrum related width parameter Δh(q) is well clustered, defining the individual seahorse clicks. The highest degree of multifractality is evident in the 18 cm male seahorse, signifying greater heterogeneity. A further comparison between the seahorse body size and weight (wet) with respect to the width parameter Δh(q) and the second-order Hurst exponent h(q=2) underscores the versatility of MFDFA as a robust statistical tool to analyze bioacoustic observations.

Some anatomical aspects of the anterior interventricular artery (anterior descending) of the human heart

The coronary arteries of 50 human hearts were studied. Muscular overbridging appeared in 19 (38 per cent) of the anterior interventricular arteries and was more frequent on the proximal third of the artery (52.6 per cent) which is usually 11.13 ñ 2.96 cm long. The middle length of the bridges was 2.8 ñ 1.6 cm. The number of collateral branches of the interventricular artery in both ventricular chambers varied widely from 2 to 20 with a mean of 8.53 ñ 4.39. The main septal branch emerged 3.85 ñ 1.12 cm from the origin the anterior interventricular artery. The other septal branches were 9.9 + 1.55 in number. Anastomosis between anterior and posterior interventricular arteries was observed in 76 per cent of the cases studied. Based on our results, we speculate about the behaviour of coronary arteries in terms of their course.

Study of the venous drainage of the thyroid gland in dogs (Canis familiaris).

The authors studied the venous drainage of the thyroid gland in about 30 adult dogs without specific race of both sexes. The study was conducted using Neoprene Latex previously stained with specific pigment injected into cervical venous system, following, after fixation, dissection with disarmed eye or under dissecting microscope (10x). When necessary the cases observed showed 90% more than one venous branch in each glandular pole: 70% one ima thyroid vein and 70% one thyroid venous arch (laringeal); about 50% of dissecting cases drainage exclusively the thyroid gland, whereas the others 50% are responsible for the drainage of surrounding structures.