Search results for " MORPHOLOGY"
showing 10 items of 543 documents
Seawater carbonate chemistry and growth, physiological performance of the Manila clam Ruditapes philippinarum
2018
Ocean acidification may interfere with the calcifying physiology of marine bivalves. Therefore, understanding their capacity for acclimation and adaption to low pH over multiple generations is crucial to make predictions about the fate of this economically and ecologically important fauna in an acidifying ocean. Transgenerational exposure to an acidification scenario projected by the end of the century (i.e., pH 7.7) has been shown to confer resilience to juvenile offspring of the Manila clam, Ruditapes philippinarum. However, whether, and to what extent, this resilience can persist into adulthood are unknown and the mechanisms driving transgenerational acclimation remain poorly understood.…
Seawater carbonate chemistry and somatic and otolith growth relationship of Symphodus ocellatus
2019
Ocean acidification (OA) may have varied effects on fish eco-physiological responses. Most OA studies have been carried out in laboratory conditions without considering the in situ pCO2/pH variability documented for many marine coastal ecosystems. Using a standard otolith ageing technique, we assessed how in situ ocean acidification (ambient, versus end-of-century CO2 levels) can affect somatic and otolith growth, and their relationship in a coastal fish. Somatic and otolith growth rates of juveniles of the ocellated wrasse Symphodus ocellatus living off a Mediterranean CO2 seep increased at the high-pCO2 site. Also, we detected that slower-growing individuals living at ambient pCO2 levels …
Decline in Coccolithophore Diversity and Impact on Coccolith Morphogenesis Along a Natural CO2 Gradient
2014
A natural pH gradient caused by marine CO2 seeps off Vulcano Island (Italy) was used to assess the effects of ocean acidification on coccolithophores, which are abundant planktonic unicellular calcifiers. Such seeps are used as natural laboratories to study the effects of ocean acidification on marine ecosystems, since they cause long-term changes in seawater carbonate chemistry and pH, exposing the organisms to elevated CO2 concentrations and therefore mimicking future scenarios. Previous work at CO2 seeps has focused exclusively on benthic organisms. Here we show progressive depletion of 27 coccolithophore species, in terms of cell concentrations and diversity, along a calcite saturation …
Vanadium Modulates Proteolytic Activities and MMP-14-Like Levels during Paracentrotus lividus Embryogenesis
2022
The increasing industrial use of vanadium (V), as well as its recent medical use in various pathologies has intensified its environmental release, making it an emerging pollutant. The sea urchin embryo has long been used to study the effects induced by metals, including V. In this study we used an integrated approach that correlates the biological effects on embryo development with proteolytic activities of gelatinases that could better reflect any metal-induced imbalances. V-exposure caused morphological/morphometric aberrations, mainly concerning the correct distribution of embryonic cells, the development of the skeleton, and the embryo volume. Moreover, V induced a concentration change …
Influence of tooth loss on mandibular morphology : a cone-beam computed tomography study
2019
Background Tooth loss adversely affects patients’ health and psychosocial wellbeing. In addition, it changes mandibular morphology. Objective: To evaluate the effect of tooth loss, age, and gender on mandibular morphology. Material and Methods Cone-beam computed tomographic (CBCT) scans of 101 patients were examined to measure the gonial angle (GA), ramus height (RH) and condylar height (CH). Patients’ age, gender, and dental status were recorded. Repeated measures analysis of variance (ANOVA) was used to assess the impact of gender, age, and tooth loss on the GA, RH and CH. The mean measurements of the GA, RH and CH were compared between dentate/edentulous patients after splitting by gende…
Über die gegenseitigen topographischen Beziehungen von Sacrum, Acetabulum und Splanchnocoel bei Vögeln [Putnu sakruma, acetabuluma un splanchnocēla s…
1936
Teksts vācu valodā, kopsavilkums latviešu valodā.
Morphological characterisation of soil structure in tilled fields: from a diagnosis method to the modelling of structural changes over time
2004
Characterisation of soit structure within the tilled layer of cultivated fields is crucial because the importance of this soil characteristic on the biological, chemical and physical properties of the soil and its repercussions on water cycle, root growth and functioning. We present in this paper a method for field characterisation of soil structure. This method, practised since the 1970s, was designed for field diagnosis of the effects of cropping systems on soil structure. It is based on a stratification of the observation face of a pit dug perpendicular to the direction of tillage and traffic: spatial compartments are distinguished, according to the nature of the mechanical stresses they…
Dermale Skelettelemente vonLissodus (Chondrichthyes: Hybodontoidea) aus dem Unterperm des Saar-Nahe-Beckens
1996
The appearance ofLissodus sp. NM in the Rotliegend of the NE Saar-Nahe basin extends the knowledge of this genus of the superfamily Hybodontoidea. Additional to some isolated teeth, which represent the most important diagnostic feature, many scales and a spine fragment could be described from the Niedermoschel locality. The functional morphology of the scales will be discussed on the basis of wellknown results from Recent sharks.
Theoretical morphology of tetrapod skull networks
2014
Abstract Network models of the tetrapod skull in which nodes represent bones and links represent sutures have recently offered new insights into the structural constraints underlying the evolutionary reduction of bone number in the tetrapod skull, known as Williston's Law. Here, we have built null network model-derived generative morphospaces of the tetrapod skull using random, preferential attachment, and geometric proximity growth rules. Our results indicate that geometric proximity is the best null model to explain the disparity of skull structures under two structural constraints: bilateral symmetry and presence of unpaired bones. The analysis of the temporal occupation of this morphosp…
Reconstitution du squelette d'astérides fossiles à partir d'ossicules isolés : intérêt taxinomique et phylogénétique
1999
Abstract Dissociated ossicles of asteroids are frequent in neritic sediments. Until now, this material was mainly used in the identification of species. A new method, associating a morphological analysis and counting of plates, allows the architecture of the skeleton and the shape of the body to be reconstructed. This method provides new elements for taxonomic and phylogenetic comparisons. It also provides indications on the adaptation of the asteroids to their environment. In geological beds, frequencies of the different kinds of plates will allow qualification of bioerosion and taphonomic sorting.