scholarly journals A GEOMETRIC MORPHOMETRIC APPROACH TO THE ANALYSIS OF THE SHAPE VARIABILITY OF THE HAPTORAL ATTACHMENT STRUCTURES OF LIGOPHORUS SPECIES (PLATYHELMINTHES: MONOGENEA)

2017 ◽  
Vol 14 ◽  
pp. 92-101
Author(s):  
Anton Lyakh ◽  
Evgenija Dmitrieva ◽  
Maryana Popyuk ◽  
Olga Shikhat ◽  
Alexandr Melnik
Keyword(s):  
Fourier Transform ◽  
Numerical Data ◽  
The Black Sea ◽  
Geometric Morphometric ◽  
Interspecific Variability ◽  
Attachment Structures ◽  
Average Form ◽  
Attachment Organ ◽  
Outline Images ◽  
Elliptic Fourier Transform

The taxonomy of Ligophorus Euzet & Suriano, 1977, like the most of monopisthocotylean monogeneans, relies heavily on the morphology of sclerites of the posterior attachment organ (haptor). Geometric morphometric approach is used to analyse variability and compare the shapes of haptoral structures of these monogeneans. We outline the shapes of the sclerities by cubic Bezier curves and store results in SVG files. Every SVG outline is reduced to a set of harmonics of Elliptic Fourier transform using ElFourier program. Harmonics are the sequence of unique numbers that describe the shape of structures and are invariant to their sizes, rotation, and orientation. They allow reconstructing source outline images, finding their average form, analyzing variability and comparing shapes in combination with other numerical data like dimensions. We use that approach to investigate intra- and interspecific variability of 400 haptoral structures of seven representatives of Ligophorus, parasitising four mullet species from the Black Sea, and to discriminate these monogeneans. This method is perspective for the creation of semiautomatic key for identification of helminthes, which are mainly distinguished by the shape and dimensions of the attachment organs. The obtained results and method prospects are discussed.

scholarly journals An Analysis of a Laminar-Turbulent Transition and Thermal Plumes Behavior in a Paramagnetic Fluid Subjected to an External Magnetic Field

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7972
Author(s):  
Anna Kraszewska ◽  
Janusz Donizak
Keyword(s):  
Magnetic Field ◽  
Fourier Transform ◽  
Fluid Flow ◽  
External Magnetic Field ◽  
Fast Fourier Transform ◽  
Numerical Data ◽  
Superconducting Magnet ◽  
Transition To Turbulence ◽  
Thermal Plume ◽  
Numerical Research

Transition to turbulence and changes in the fluid flow structure are subjects of continuous analysis and research, especially for unique fields of research such as the thermo-magnetic convection of weakly magnetic fluids. Therefore, an experimental and numerical research of the influence of an external magnetic field on a natural convection’s fluid flow was conducted in the presented research. The experimental part was performed for an enclosure with a 0.5 aspect ratio, which was filled with a paramagnetic fluid and placed in a superconducting magnet in a position granting the enhancement of the flow. The process was recorded as temperature signals from the thermocouples placed in the analyzed fluid. The numerical research enabled an investigation based not only on temperature, but velocities as well. Experimental and numerical data were analyzed with the application of extended fast Fourier transform and wavelet analysis. The obtained results allowed the determination of changes in the nature of the flow and visualization of the influence of an imposed strong magnetic field on a magnetic fluid. It is proved that an applied magnetic field actuates the flow in Rayleigh-Benard convection and causes the change from laminar to turbulent flow for fairly low magnetic field inductions (2T and 3T for ΔT = 5 and 11 °C respectively). Fast Fourier transform allowed the definition of characteristic frequencies for oscillatory states in the flow, as well as an observation that the high values of magnetic field elongate the inertial range of the flow on the power spectrum density. Temperature maps obtained during numerical simulations granted visualizations of thermal plume formation and behavior with increasing magnetic field.

scholarly journals Hooked on you: shape of attachment structures in cymothoid isopods reflects parasitic strategy

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Charles Baillie ◽  
Rachel L. Welicky ◽  
Kerry A. Hadfield ◽  
Nico J. Smit ◽  
Stefano Mariani ◽  
...  
Keyword(s):  
Least Squares ◽  
Ordinary Least Squares ◽  
Least Squares Regression ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Parasite Ecology ◽  
Attachment Structures ◽  
Main Driver ◽  
Shared Ancestry ◽  
Host Exploitation

Abstract Background Parasite attachment structures are critical traits that influence effective host exploitation and survival. Morphology of attachment structures can reinforce host specificity and niche specialisation, or even enable host switching. Therefore, it is important to understand the determinants of variation in attachment structures. Cymothoid isopods are striking ectoparasites of fishes that include the infamous ‘tongue-biters.’ They are known to parasitise hosts in one of four qualitatively distinct anatomical regions. Here, we quantify variation in cymothoid attachment structures — hook-like appendages called dactyli — and test whether differences in dactylus shape are correlated with parasite mode (where they attach), allometry, or both, using multivariate ordinary least squares regression. We also assess the influence of shared ancestry on shape using a molecular phylogeny to weight our models using phylogenetic generalised least squares regression. Results We find clear differences in shape between externally-attaching and internally-attaching cymothoids but also between anterior and posterior dactyli across various species with the same attachment mode. Allometric effects are significant for anterior but not posterior dactyli. Mouth-attaching species show greater shape variability than gill- and mouth-attaching species. We find no evidence that there are clade-specific patterns of association between parasite mode and dactylus shape. Conclusions Parasite mode appears to be the main driver of attachment morphology. This likely reflects several components of parasite ecology including feeding and functional demands of attachment in different microhabitats. Geometric morphometric approaches to the quantification of shape variation of simple structures is an effective tool that provides new insights into the evolvability of parasite attachment.

scholarly journals Imbalance Detection of Rotor Rotational Speed Using Doppler Radar

2021 ◽  
Vol 21 (2) ◽  
pp. 111-118
Author(s):  
Young-Jae Choi ◽  
In-Sik Choi
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Wind Turbine ◽  
Rotational Speed ◽  
Doppler Radar ◽  
Numerical Data ◽  
Accumulated Damage ◽  
The Difference

In operating a wind turbine, both predictive and condition-based maintenances are required to minimize the downtime caused by maintenance. The imbalance of rotor rotational speed is an important factor for diagnosing wind turbine failures. The rotational speed imbalance can be caused by accumulated damage or the accumulation of ice, dust, and moisture. In this paper, we proposed a method for detecting the rotational speed imbalance of a wind turbine using a Doppler radar. We calculated the difference in the rotational speed for different times using spectrograms obtained by observing the wind turbine with a Doppler radar and determined the rotational speed imbalance using the fast Fourier transform. The performance of the proposed algorithm was verified using both synthetic and numerical data.

Descriptions of two loxosomatids (Entoprocta), with emphasis on a relationship between symbiont attachment structures and host cuticle

2000 ◽  
Vol 78 (1) ◽  
pp. 110-120 ◽  
Author(s):  
J B Williams
Keyword(s):  
New Species ◽  
Individual Animal ◽  
Exact Location ◽  
Adhesive Disc ◽  
Short Stalk ◽  
Attachment Structures ◽  
A New Species ◽  
Attachment Organ ◽  
Single Ovary

Information is provided on a new species of Loxosomella, L. diopatricola, with unusual characteristics that is symbiotic with tubicolous polychaetes of the genus Diopatra. Plasticity is displayed in the morphology of the attachment organ: the new loxosomatid possesses a stalk terminating in either a persistent pedal gland or an enlarged adhesive disc. An individual animal develops one or other of the two stalk morphologies according to its exact location on the host and the thickness of the underlying cuticle. The host epidermis underlying individuals with an adhesive disc is, in turn, modified, suggesting that these symbionts may negatively affect their hosts. Females possessed a single ovary, nearly always on the left side. The larva lacks eyespots. Buds were borne only by males. A minute species of Loxosomella commensal on polychaetes of the genus Eunice, characterised by 6 tentacles and a very short stalk, is also described. A grooved foot is present in the bud and a pedal gland is retained in the adult. The larva apparently undergoes metamorphosis.

Treatment field shape verification using elliptic Fourier transform

1999 ◽  
Vol 26 (11) ◽  
pp. 2415-2421 ◽  
Author(s):  
Qinghuai Gao ◽  
Fang-Fang Yin ◽  
Kaiwen Nie
Keyword(s):  
Fourier Transform ◽  
Elliptic Fourier Transform

scholarly journals Evaluation Method Applying Fourier Transform Analysis for Conditioned Polishing Pad Surface Topography

2011 ◽  
Vol 5 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Keiichi Kimura ◽  
◽  
Panart Khajornrungruang ◽  
Takahisa Okuzono ◽  
Keisuke Suzuki
Keyword(s):  
Fourier Transform ◽  
Surface Topography ◽  
Laser Scanning ◽  
Evaluation Method ◽  
Three Dimensional ◽  
Power Spectra ◽  
Numerical Data ◽  
Confocal Laser ◽  
Polishing Pad ◽  
Wide Range

The Fourier transform analysis is proposed to quantitatively evaluate the 3D surface topography of Chemical Mechanical Polishing (CMP) pads used for flattening and smoothing processed semiconductor substrates. The conditioned polishing pad surfaces have a wide range of irregular topographies ranging from topographies of a sub-micrometer to those of a hundredmicrometer order. Hence, a Confocal Laser Scanning Microscope (CLSM), which can provide nanometer resolution in wide range of lateral directions by means of linear encoded mechanical stage translation, was employed to obtain numerical data of the three-dimensional topographic surfaces of polishing pad samples. The measured topographic surfaces were analyzed using the spatial Fourier transform. We discuss the power spectrum in the spatial wavelengths of polishing pad surfaces which were conditioned with diamond grits of various shapes. The analyzed power spectra indicated that the surface topography characteristics varied with differently shaped diamond grits of the same size. The diamond grits roughened the polishing pad surface. We also found that a rough polishing pad surface, one that was roughed in a spatial wavelength that of less than 20 micrometers, removed more material than comparatively smooth pad surfaces.

scholarly journals Morphological and Molecular Studies of the Rapa Whelk, Rapana venosa (Neogastropoda, Muricidae), from Odesa Bay

Zoodiversity ◽  
2021 ◽  
Vol 55 (6) ◽  
pp. 467-478
Author(s):  
H. Morhun ◽  
M. O. Son ◽  
O. O. Kovtun ◽  
S. Utevsky
Keyword(s):  
Black Sea ◽  
Molecular Genetic ◽  
Coi Gene ◽  
Shell Shape ◽  
The Black Sea ◽  
Shell Weight ◽  
Geometric Morphometric ◽  
Rapana Venosa ◽  
Molecular Genetic Test ◽  
Shape Data

The gastropod Rapana venosa (Valenciennes, 1846) is a successful worldwide invader occurring in the Black Sea. The aim of this study is to overview specific population features of this mollusk from Odesa Bay through integrative systematic approach by means of morphological and molecular research. For this purpose, the mollusks were collected from the Black Sea and examined using morphological methods: traditional morphometry, which employs linear parameters of shells (height, width, whorl height, whorl width, height of the last whorl) and shell weight, and geometric morphometrics of the shell shape data. For a molecular genetic test, the COI gene region was used. Among all conchological variability, the two morphotypes were defined: the first has a “broad” shape — shells have a thick and durable last whorl and a low spire, and the second one — “extended” shape: shells are relatively slender with an elongated high-conical spire. According to the geometric morphometric data, R. venosa has statistically significant differences between defined morphotypes (F = 4.12, p = 0.001); however, the shapes in males and females are not significantly different (F = 1.13, p = 0.318). No genetic diversity, neither novel haplotypes were revealed by the molecular analysis: in Odesa Bay, the haplotype occurring also in other regions of invasion across the world is present.

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