Search results for "Onyx"
showing 10 items of 10 documents
The migration path of Gondwanian dinosaurs toward Adria: New insights from the Cretaceous of NW Sicily (Italy)
2021
Abstract The increasing dinosaur record from Italy questioned classic palaeogeographic scenarios for the Central Mediterranean area and suggest the proximity of landmass areas and a geographical connection between Gondwana and Laurasia during Cretaceous times. Besides several track-sites and exceptionally-preserved specimens (e.g. Scipionyx samniticus), the Italian dinosaur record also consists of isolated bones, among which the bone fragment of a theropod discovered in north-western Sicily. The bone occurs in a shallow-water carbonate succession (i.e. Pizzo Muletta, Palermo Mountains) pertaining to the Panormide Carbonate Platform (PCP). The bone was previously ascribed to the Cenomanian, …
Response of an arctic predator guild to collapsing lemming cycles
2012
6 pages; International audience; Alpine and arctic lemming populations appear to be highly sensitive to climate change, and when faced with warmer and shorter winters, their well-known high-amplitude population cycles may collapse. Being keystone species in tundra ecosystems, changed lemming dynamics may convey significant knock-on effects on trophically linked species. Here, we analyse long-term (1988-2010), community-wide monitoring data from two sites in high-arctic Greenland and document how a collapse in collared lemming cyclicity affects the population dynamics of the predator guild. Dramatic changes were observed in two highly specialized lemming predators: snowy owl and stoat. Follo…
Climate change and cyclic predator-prey population dynamics in the high Arctic.
2009
The high Arctic has the world's simplest terrestrial vertebrate predator–prey community, with the collared lemming being the single main prey of four predators, the snowy owl, the Arctic fox, the long-tailed skua, and the stoat. Using a 20-year-long time series of population densities for the five species and a dynamic model that has been previously parameterized for northeast Greenland, we analyzed the population and community level consequences of the ongoing and predicted climate change. Species' responses to climate change are complex, because in addition to the direct effects of climate change, which vary depending on species' life histories, species are also affected indirectly due to…
Data from: Plant – herbivorous beetle networks: molecular characterization of trophic ecology within a threatened steppic environment
2015
DNA barcoding facilitates many evolutionary and ecological studies, including the examination of the dietary diversity of herbivores. In this study, we present a survey of ecological associations between herbivorous beetles and host plants from seriously threatened European steppic grasslands. We determined host plants for the majority (65%) of steppic leaf beetles (55 species) and weevils (59) known from central Europe using two barcodes (trnL and rbcL) and two sequencing strategies (Sanger for mono/oligophagous species and Illumina for polyphagous taxa). To better understand the ecological associations between steppic beetles and their host plants, we tested the hypothesis that leaf beetl…
Late Pleistocene (MIS 3-4) climate inferred from micromammal communities and δ18O of rodents from Les Pradelles, France.
2013
The middle Paleolithic stratigraphic sequence of Les Pradelles (Charente, France) spans from the end of Marine Isotope Stage (MIS) 4 until the middle of MIS 3. Micromammal remains are present in all the stratigraphic levels, offering a rare opportunity to address the questions of both environmental and climatic fluctuations throughout this period. Climate modes were studied through the taphonomy, biodiversity and oxygen isotope compositions of phosphate (δ18O p ) from 66 samples of rodent tooth enamel. The δ18O p values from the lower sedimentary levels provide summer mean air temperatures of 19 ± 2°C (level 2/1) and of 16 ± 2°C (levels 2A, 2B and 4A). Within the middle of sequence (level 4…
Miega artērijas audzēju ķirurģiska ārstēšana Latvijā no 2010. līdz 2015.gadam
2016
Ievads: Miega artēriju audzēji (MAA) ir reti, lēni augoši un labi apasiņoti neiroendokrīni veidojumi, kuru izcelsme ir miega artērijas bifurkācijas līmenī esošās paraganglionārās šūnas. Mērķis: Pētījuma mērķis bija izpētīt MAA pacientus Latvijā pēdējo piecu gadu laikā, veicot demogrāfisku, kā arī ārstēšanās iznākumu analīzi. Materiāli un metodes: Tika veikta retrospektīva analīze, caurskatot pacientu slimības vēstures no 2010. līdz 2015. gadam Paula Stradiņa Klīniskās Universitātes slimnīcā, kurā esošais asinsvadu ķirurģijas centrs ir vadošais Latvijā, kurā ārstē MAA. Pētījuma ietvaros pacienti tika arī uzaicināti uz duplex ultrasonogrāfiju apsekošanai. Rezultāti: Kopumā 10 pacientiem tika …
Apoptosis: a relevant tool for anticancer therapy.
2006
Apoptosis is a form of cell death that permits the removal of damaged, senescent or unwanted cells in multicellular organisms, without damage to the cellular microenvironment. Defective apoptosis represents a major causative factor in the development and progression of cancer. The majority of chemotherapeutic agents, as well as radiation, utilize the apoptotic pathway to induce cancer cell death. Resistance to standard chemotherapeutic strategies also seems to be due to alterations in the apoptotic pathway of cancer cells. Recent knowledge on apoptosis has provided the basis for novel targeted therapies that exploit apoptosis to treat cancer. These new target include those acting in the ext…
OSSERVAZIONI DI ZYGONYX TORRIDUS (KIRBY 1889) (Insecta Odonata) IN ITALIA
2015
Records of Zygonyx torridus (Kirby 1889) (Insecta Odonata) in Italy.
Data from: Demographic responses of a site-faithful and territorial predator to its fluctuating prey: long-tailed skuas and arctic lemmings
2013
1. Environmental variability, through interannual variation in food availability or climatic variables, is usually detrimental to population growth. It can even select for constancy in key life-history traits, though some exceptions are known. Changes in the level of environmental variability are therefore important to predict population growth or life-history evolution. Recently, several cyclic vole and lemming populations have shown large dynamical changes, that might affect rodent predator demography or life histories. 2. Skuas constitute an important case study among rodent predators, because of their strongly saturating breeding productivity (they lay only two eggs) and high degree of …
Emergency Endovascular Treatment of Petrous Carotid Artery False Aneurysm
2015
Abstract Introduction The management of ruptured intracranial false aneurysms (IFAs) might be tricky as any kind of treatment modality, surgical or endovascular, is burdened with significant challenges. A case report of the endovascular treatment of IFA in emergency setting is presented to provide more understanding of its pathophysiology as well as of the best operative work-up for petrous carotid artery reconstruction. Methods Technical notes from a left sided skull base abscess, involving and eroding the carotid canal and petrous carotid artery (PCA) resulting in an IFA are shown and analyzed. Results Balloon-assisted low viscosity Onyx embolization seems an effective method for the emer…