Search results for "morphometrics"
showing 10 items of 108 documents
Echinostomes: systematics and life cycles
2008
This chapter provides a review of the most significant literature in the last decade on the systematics and biology of echinostomes and echinostome-like digeneans. This review is primarily concerned with members of the genus Echinostoma, although members of other genera (Echinoparyphium, Echinochasmus, Himasthla, Hypoderaeum, Petasiger, Euparyphium, Stephanoprora, Isthmiophora, and Acanthoparyphium) and echinostome-related genera (Parorchis, Philophthalmus and Ribeiroia) are also considered. The literature on molecular systematics and morphometrics of these trematodes is reviewed. Specific mention is made of the life cycle patterns of echinostome and echinostome-like digeneans along with an…
Brain Cortical Complexity and Subcortical Morphometrics in Lifelong Premature Ejaculation
2020
Premature ejaculation (PE) is the most common male sexual dysfunction. The brain disturbances that cause this disorder remain poorly understood. This study aimed to investigate how the morphology of cortical and subcortical brain structures differed in PE, how these morphologic differences were associated with severity measures of PE, such as intravaginal ejaculatory latency time (IELT), and how these cortical and subcortical structures were causally connected through mediation analysis. Anatomical MRI scans were acquired from 39 male participants, 23 with PE (28.78 ± 4.32 years), and 16 without PE (27.88 ± 3.65 years). We used a subcortical analysis package within FSL to perform subcortica…
Morphometrics of Second Iron Age ceramics - strengths, weaknesses, and comparison with traditional typology.
2014
12 pages; International audience; Although the potential of geometric morphometrics for the study of archaeological artefacts is recognised, quantitative evaluations of the concordance between such methods and traditional typology are rare. The present work seeks to fill this gap, using as a case study a corpus of 154 complete ceramic vessels from the Bibracte oppidum (France), the capital of the Celtic tribe Aedui from the Second Iron Age. Two outline-based approaches were selected: the Elliptic Fourier Analysis and the Discrete Cosine Transform. They were combined with numerous methods of standardisation/normalisation. Although standardisations may use either perimeter or surface, the res…
Autecology, lifestyle and hydrodynamics of early vertebrates
2018
Capítulo 1. Introducción general Los vertebrados constituyen uno de los grupos de animales más exitosos, contando con más de 60000 especies distintas y ocupando la gran mayoría de ecosistemas marinos y continentales. Su origen y evolución han sido temas centrales para biólogos y paleontólogos durante décadas, pero las discusiones en este sentido se han visto obstaculizadas porque los grupos actuales (ciclóstomos, condrictios y osteíctios) constituyen solo una pequeña representación de toda la diversidad que existió en el pasado. Por lo tanto, el registro fósil es crucial para arrojar luz sobre estos aspectos permitiendo desvelar el momento y el tempo de la aparición de los diferentes caract…
Morphometrics of hard structures in cuttlefish
2006
7 pages; International audience; Cuttlefishes exhibit several hard structures that have been characterised using morphometric analysis. Most of these data come from cuttlebones, although statoliths and beaks are also used. It appears that morphometric techniques are mainly used for taxonomic purposes. However, some analyses have emphasised functional morphology and macroevolution. Morphological features (including the inner shell) of cuttlefishes and their availability for study (numerous specimens, culture in the laboratory) make them a first rank model for numerous studies in life sciences that require morphometrics, and especially in the field of evolutionary biology.
Développement postnatal et évolution du complexe craniofacial chezles rongeurs
2022
Understanding developmental mechanisms in evolution is crucial to apprehend the diversification of organismal forms. In mammals, changes occur during all development phases (prenatal and postnatal). Postnatal growth plays an essential role in the acquisition of the adult shape. During this period, the craniofacial complex undergoes many changes in functional constraint forcing the different tissue to accommodate while adjusting, along the growth and at the adult stage, to a certain level of functional performance. These different developmental interactions respond to several influencing factors such as molecular, genetic and cellular processes but also the environment. The latter will play …
Human-induced hybridization and population bottleneck : population genetics, morphometrics and parasitology applied to the invaded and invasive tilap…
2011
Biological invasions are recognized as a significant evolutionary factor over short time scales. In particular, their effect is well recorded on the genetic structure of populations, the patterns of phenotypic evolution and the richness of parasite fauna associated to invasive populations. This study aims at quantifying the consequences of a biological invasion according to these three levels (genetical, phenotypical and parasitological) taking as example the Mozambique tilapia Oreochromis mossambicus. This African cichlid is characterized by an unusual conservation status since it is both (i) ranked among the world’s worst invasive species due to its global dispersion during the 20th centu…
Supplementary material 13 from: Van Cann J, Virgilio M, Jordaens K, De Meyer M (2015) Wing morphometrics as a possible tool for the diagnosis of the …
2015
Individual assignments to genotypic clusters A, F1, F2, R1, R2: Explanation note: Posterior group membership probabilities (PGMPs) of male and female specimens as resulting from Discriminant Analysis of Principal Coordinates of wing landmarks (upper) or wing band areas (lower). Prior groups: A, F1, F2, R1, R2 (from white to dark blue).
Supplementary material 11 from: Van Cann J, Virgilio M, Jordaens K, De Meyer M (2015) Wing morphometrics as a possible tool for the diagnosis of the …
2015
Constrained ordination of wing band areas: Explanation note: Discriminant analysis of principal coordinates (DAPC) maximising morphometric differences in wing band areas between males and females (a) Ceratitis anonae, Ceratitis fasciventris and Ceratitis rosa and (b) genotypic clusters A, F1, F2, R1, R2.
Supplementary material 8 from: Van Cann J, Virgilio M, Jordaens K, De Meyer M (2015) Wing morphometrics as a possible tool for the diagnosis of the C…
2015
Unconstrained ordination of wing landmarks: Explanation note: Principal component analysis (PCA) showing morphometric differences in wing landmarks between males and females (a) Ceratitis anonae, Ceratitis fasciventris and Ceratitis rosa and (b) genotypic clusters A, F1, F2, R1, R2.