1,152 research outputs found

    Olfactory Sex Recognition Investigated in Antarctic Prions

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    Chemical signals can yield information about an animal such as its identity, social status or sex. Such signals have rarely been considered in birds, but recent results have shown that chemical signals are actually used by different bird species to find food and to recognize their home and nest. This is particularly true in petrels whose olfactory anatomy is among the most developed in birds. Recently, we have demonstrated that Antarctic prions, Pachyptila desolata, are also able to recognize and follow the odour of their partner in a Y-maze

    El equus stenonis cocchi como indicador biostatigráfico del plio-pleistoceno en Italia y España

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    [Resumen] Se esquematiza la cronoestratigrafía de los principales yacimientos de Vertebrados italianos del Plio-pleistoceno, de el Villafranquiense medio al Galerino. Se estudia, desde un punto de vista evolutivo, la presencia de las distintas formas de Equus stenonis Cocchi hasta la llegada de Equus caballus Linn. La comparación de los distintos estadios evolutivos de E. stenonis y su fauna acompañante permiten la elaboración de un Cuadro sinóptico en el cual los yacimientos españoles con Equus se correlacionan con sus sincrónicos italianos sobre una base estratigráfica comparada (BONADONNA, 1982; ARIAS et all., 1982) con los principales eventos geológicos en Europa[Abstract] The chronostratigraphy of the Plio-pleistocene marnmals italian deposits from middle Villafranchian to Galerian is surnmarized. The presence of different forms of Equus stenonis Cocchi until the appearance of the first kinds of Equus caballus Linn. is studied by an evolutive point of view. The comparison among the different evolutive levels of Equus stenonis and the associated fauna allow us to build a synoptic Table in which the spanish deposits with Equus are correlate to analogous italian ones ln a stratigraphic scale yet compared (BONADONNA, 1982; ARIAS et all., 1982) to the most important geological event ln Europ

    First GPS-tracking of Cory’s shearwater in the Mediterranean Sea.

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    The behaviour and the ecology of seabirds such as albatrosses, petrels and shearwaters have been subject of numerous studies, often employing the most recent technologies to track birds during their foraging trips. Until now, however, big oceanic species have been preferred for these studies because of the dimensions and weight of the devices. New light GPS loggers (<9g) were used to track foraging trips of a medium-sized species, the Cory’s shearwater, for the first time in the Mediterranean Sea. The tracks obtained in our study showed that Mediterranean Cory’s shearwaters alternatively used one of two different fishing areas. Various explanations could account for this difference; one of these could be that the two directions have a different relevance for the birds being for chick- and self-provisioning. This study provides new hypotheses concerning the behaviour of Cory’s shearwaters in the Mediterranean Sea, which is a different environment respect to previously studied oceans

    “L’inganno degli occhi”. Borromini’s perspectival niche for the Casa dei Filippini in Rome

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    The RCIN 905602 sheet of the Royal Collection, Windsor contains an orthogonal projection presentation drawing made by Francesco Borromini in 1627 and showing one of Gianlorenzo Bernini's proposals for the Tomb of Urban VIII. The apsidal frame rendered in perspective can be related to the perspective niche that Borromini himself placed above the fictitious entrance in the center of the facade of the Casa dei Filippini in Rome a few years later. The sheet is studied here in the context of the influence that the diffusion of representation methods and practices has had on the forms of architecture as well as their visual perception. After discussing the reason for the construction of such a perspective device, its representation in the design documents and its reception in the images of the square after its construction, the authors present the results of a geometric analysis and reconstruction after photo-modeling ot the niche itself, aimed at determining the position of the ideal observer on the square considered in designing the device, and they discuss the relationship between this spatial stratagem and the graphic trick atopted in the tomb design

    Avian olfactory receptor gene repertoires: evidence for a well-developed sense of smell in birds?

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    Among vertebrates, the sense of smell is mediated by olfactory receptors (ORs) expressed in sensory neurons within the olfactory epithelium. Comparative genomic studies suggest that the olfactory acuity of mammalian species correlates positively with both the total number and the proportion of functional OR genes encoded in their genomes. In contrast to mammals, avian olfaction is poorly understood, with birds widely regarded as relying primarily on visual and auditory inputs. Here, we show that in nine bird species from seven orders (blue tit, Cyanistes caeruleus; black coucal, Centropus grillii; brown kiwi, Apteryx australis; canary, Serinus canaria; galah, Eolophus roseicapillus; red jungle fowl, Gallus gallus; kakapo, Strigops habroptilus; mallard, Anas platyrhynchos; snow petrel, Pagodroma nivea), the majority of amplified OR sequences are predicted to be from potentially functional genes. This finding is somewhat surprising as one previous report suggested that the majority of OR genes in an avian (red jungle fowl) genomic sequence are non-functional pseudogenes. We also show that it is not the estimated proportion of potentially functional OR genes, but rather the estimated total number of OR genes that correlates positively with relative olfactory bulb size, an anatomical correlate of olfactory capability. We further demonstrate that all the nine bird genomes examined encode OR genes belonging to a large gene clade, termed γ-c, the expansion of which appears to be a shared characteristic of class Aves. In summary, our findings suggest that olfaction in birds may be a more important sense than generally believed

    Paleoclimatic and paleobiological correlations by mammal faunas from Southern America and SW Europe

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    Proceedings of the 1" R.C.A.N.S. Congress, Lisboa, October 1992The preliminary results of a research dealing with the study of global changes in the last 5 Ma by correlations of continental records between the Northern and the Southern Hemispheres (SW Europe and Argentina, respectively) are reported. The first analyses of the evolutionary patterns point out, in Argentina, two different turnover times: the first one is characterized by a high percentage of mammalautochthonous extinctions placed in the span of time between the last Chapadmalalan and the first Ensenadan faunas, around 2.5-2.3 Ma. It is possible to identify a high percentage of new immigrant genera from North America in the first turnover, while the second one, associated to the "last Pleistocene megafaunal extinctions", probably occurred at the beginning of the "Glacial Pleistocene", around 1.0-0.8 Ma. The oxygen isotope composition of phosphate from fossil mammal bones was measured to have a better climatic resolution from faunal elements of two hemispheres and to compare them by results as quantitative as possible. The preliminary efforts are brought out on fourteen deposits from SE Spain. Isotopic and chemical results strongly suggest the existence of a relation between the oxygen isotope composition in various skeletal components and the taphonomic processes of a single deposit. The variations of 0180 in the mammal teeth of Equidae from SE Spain suggest a shift towards a colder environment from the older one, Huelago, to more recent deposits, as well as from Venta Micena to Fuensanta in agreement with the transition from the Middle to the Upper Villafranchian, around 2.5 Ma, and the transition between the "Preglacial" to the "Glacial" Pleistocene, around 1.9-0.8 Ma

    Sodium-glucose cotransporter 2 inhibitors antagonize lipotoxicity in human myeloid angiogenic cells and ADP-dependent activation in human platelets: Potential relevance to prevention of cardiovascular events

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    Background: The clear evidence of cardiovascular benefits in cardiovascular outcome trials of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in type 2 diabetes might suggest an effect on atherosclerotic plaque vulnerability and/or thrombosis, in which myeloid angiogenic cells (MAC) and platelets (PLT) are implicated. We tested the effects of SGLT2i on inflammation and oxidant stress in a model of stearic acid (SA)-induced lipotoxicity in MAC and on PLT activation. The possible involvement of the Na+/H+ exchanger (NHE) was also explored. Method: MAC and PLT were isolated from peripheral blood of healthy subjects and incubated with/without SGLT2i [empagliflozin (EMPA) and dapagliflozin (DAPA) 1-100 μM] to assess their effects on SA (100 μM)-induced readouts of inflammation, oxidant stress and apoptosis in MAC and on expression of PLT activation markers by flow-cytometry after ADP-stimulation. Potential NHE involvement was tested with amiloride (aspecific NHE inhibitor) or cariporide (NHE1 inhibitor). Differences among culture conditions were identified using one-way ANOVA or Friedman test. Results: NHE isoforms (1,5-9), but not SGLT2 expression, were expressed in MAC and PLT. EMPA and DAPA (100 μM) significantly reduced SA-induced inflammation (IL1β, TNFα, MCP1), oxidant stress (SOD2, TXN, HO1), but not apoptosis in MAC. EMPA and DAPA (both 1 μM) reduced PLT activation (CD62p and PAC1 expression). SGLT2i effects were mimicked by amiloride, and only partially by cariporide, in MAC, and by both inhibitors in PLT. Conclusions: EMPA and DAPA ameliorated lipotoxic damage in stearate-treated MAC, and reduced ADP-stimulated PLT activation, potentially via NHE-inhibition, thereby pointing to plaque stabilization and/or thrombosis inhibition as potential mechanism(s) involved in SGLT2i-mediated cardiovascular protection
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