Search results for "Vertebrates"
showing 10 items of 440 documents
The Abruzzo-Apulian (Central and Southeastern Italy) fossil fauna, new challenges for paleontologists and paleobiogeographers
2012
The Abruzzo-Apulian Platform was an endemic Neogene paleobioprovince. Its relics can be found at the south-east of the Italian Peninsula. Geological and paleontological traces of this past land crop out both in the central Apennines, Maiella (Scontrone fossiliferous site), as well as in the Gargano Promontory. The Scontrone paleofauna -Scontrone is placed on the southern borderline of the Abruzzo National Park, Central-Southern Apennine. The bone-bearing sediments are coastaltidal-flat calcarenites stratigraphically dated to the Lower Tortonian. They yielded remains of terrestrial mammals, which include the bizarre ruminant Hoplitomeryx and the giant insectivore Deinogalerix, of a large ter…
Editorial: CSF1R, CSF-1, and IL-34, a "menage a trois" conserved across vertebrates.
2010
Abstract Editorial discusses the perspectives opened by the recently discovered IL-34, its conservation across species in the biology of the cytokine CSF-1, and identification of a new CSF-1R ligand that could together account for the well-known heterogeneity of monocytes.
An Inhibitor of Cytochrome Oxidase Activity in the Sea Urchin Egg
1959
PREVIOUS work in this laboratory1,2 has demonstrated the presence of a highly active cytochrome oxidase in the isolated mitochondria of unfertilized sea urchin eggs. This activity is only 25 per cent lower than that of the mitochondria of the newly fertilized egg and up to the blastula stage2. No cytochrome oxidase activity has been found other than in the mitochondria1,3. On the other hand, it is known that the oxygen consumption of the unfertilized sea urchin egg is quite low; fertilization restores a normal respiratory level which increases continuously during the early development (for a discussion, see ref. 4). The suggestion was then made2 that in the unfertilized egg an extra-mitocho…
Introduction to Symposium: Poecilogony--A Window on Larval Evolutionary Transitions in Marine Invertebrates
2012
Poecilogony is the intraspecific variation in developmental mode that has been described in some marine invertebrates. Poecilogonous species produce different larval forms (e.g., free-swimming planktotrophic larvae as well as brooded lecithotrophic or adelphophagic larvae). Poecilogony can be a controversial topic, since it is difficult to identify and characterize the phenomenon with certainty. It has been challenging to determine whether poecilogony represents developmental polymorphism with a genetic basis or developmental polyphenism reflecting plastic responses to environmental cues. Other outstanding questions include whether common mechanisms underlie the developmental variation we o…
Cytotoxic Activity of Tunicate Hemocytes
1996
Tunicates (protochordates) are filter-feeding marine invertebrates with a worldwide distribution. In their larval form, they exhibit many of the features characteristic of the vertebrates. The larva, with a tail, notochord, and dorsal neural tube, upon settlement undergoes a remarkable metamorphosis in which it loses most of its chordate characteristics and becomes a sessile invertebrate adult. Thus, due to these characteristics, tunicates are considered to be the most primitive members of the phylum Chordata. Owing to their position in the phylogenetic line leading to the vertebrates, they have attained importance as experimental organisms and have been examined by researchers from a varie…
Insight into the role of cetaceans in the life cycle of the tetraphyllideans (Platyhelminthes: Cestoda)
2007
Abstract Four types of tetraphyllidean larvae infect cetaceans worldwide: two plerocercoids differing in size, ‘small’ (SP) and ‘large’ (LP), and two merocercoids referred to as Phyllobothrium delphini and Monorygma grimaldii . The latter merocercoid larvae parasitize marine mammals exclusively and exhibit a specialised cystic structure. Adult stages are unknown for any of the larvae and thus the role of cetaceans in the life cycle of these species has been a long-standing problem. The SP and LP forms are thought to be earlier stages of P. delphini and M. grimaldii that are presumed to infect large pelagic sharks that feed on cetaceans. A molecular analysis of the D2 variable region of the …
A bug's life: Delving into the challenges of helminth microbiome studies.
2020
The body of vertebrates is inhabited by trillions of microorganisms, i.e. viruses, archaea, bacteria and unicellular eukaryotes, together referred to as the ‘microbiota’. Similarly, vertebrates also host a plethora of parasitic worms (the ‘macrobiota’), some of which share their environment with the microbiota inhabiting the gastrointestinal tract [1]. Complex interactions between the helminths and the gut microbiota have been associated with establishment of parasite infection, disease manifestations, and host immune-modulation [2, 3]. Remarkably, not only enteric helminths alter the 26 gut microbiome composition [4], but also the infection with blood flukes of the genus Schistosoma has be…
Morphological and Postural Changes in the Foot during Pregnancy and Puerperium: A Longitudinal Study
2021
The aim of this study is to observe the morphological and postural changes to the foot that take place during pregnancy and the puerperium. Method: In this descriptive, observational, longitudinal study, we analysed 23 pregnant women, with particular attention to morphological and postural aspects of the foot, at three time points during and after pregnancy: in weeks 9–13 of gestation, weeks 32–35 of gestation and weeks 4–6 after delivery. The parameters considered were changes in foot length, the Foot Posture Index (FPI) and the Hernández Corvo Index, which were analysed using a pedigraph and taking into account the Body Mass Index (BMI). The same procedure was conducted in each review. Re…
Lumbriculus variegatus (Annelida) biological responses and sediment sequential extractions indicate ecotoxicity of lake sediments contaminated by bio…
2018
Abstract We assessed potential ecotoxicity of lake sediments affected by biomining effluents in northeastern Finland. Growth, reproduction and behavior of the sediment-dwelling oligochaete Lumbriculus variegatus (Muller 1774) were used as ecotoxicity endpoints. Standardized chronic bioassays were used for growth and reproduction, and acute and chronic tests with Multispecies Freshwater Biomonitor (MFB) for behavior assessments. Sequential extractions were used to characterize metal bioavailability and exposure conditions in the sediments, which indicated mining-induced contamination gradients of S, Cu, Ni and U and also bioavailability gradients of S and Ni. Among the ecotoxicity endpoints,…
Toxicity of Mining-Contaminated Lake Sediments to Lumbriculus variegatus
2021
AbstractBoreal lakes with soft water and low buffering capacity are susceptible to excess ion loading resulting from metal mining. The impact of two Finish mining sites in downstream lakes was assessed with a chronic sediment toxicity test using a laboratory-reared freshwater Lumbriculus variegatus (Oligochaeta). The test organisms were exposed to mining-contaminated natural lake sediments and hypolimnion water (HLW) or artificial freshwater (AFW) as overlying water in two independent experimental setups. In both test setups, growth and reproduction of L. variegatus were lower in sediments from the lakes receiving high amount of mining effluents from the mines nearby. In the biomining site,…