34 research outputs found
Brief Exposure to Sensory Cues Elicits Stimulus-Nonspecific General Sensitization in an Insect
The effect of repeated exposure to sensory stimuli, with or without reward is well known to induce stimulus-specific modifications of behaviour, described as different forms of learning. In recent studies we showed that a brief single pre-exposure to the female-produced sex pheromone or even a predator sound can increase the behavioural and central nervous responses to this pheromone in males of the noctuid moth Spodoptera littoralis. To investigate if this increase in sensitivity might be restricted to the pheromone system or is a form of general sensitization, we studied here if a brief pre-exposure to stimuli of different modalities can reciprocally change behavioural and physiological responses to olfactory and gustatory stimuli. Olfactory and gustatory pre-exposure and subsequent behavioural tests were carried out to reveal possible intra- and cross-modal effects. Attraction to pheromone, monitored with a locomotion compensator, increased after exposure to olfactory and gustatory stimuli. Behavioural responses to sucrose, investigated using the proboscis extension reflex, increased equally after pre-exposure to olfactory and gustatory cues. Pheromone-specific neurons in the brain and antennal gustatory neurons did, however, not change their sensitivity after sucrose exposure. The observed intra- and reciprocal cross-modal effects of pre-exposure may represent a new form of stimulus-nonspecific general sensitization originating from modifications at higher sensory processing levels
Modeling habitat suitability of the invasive clam Corbicula fluminea in a Neotropical shallow lagoon, southern Brazil
Exogenously Applied Jasmonic Acid Induces Changes in Apical Meristem Morphology of Potato Stolons
Influencia del tratamiento en las caracterĂsticas del agua de abastecimiento de Logroño
Influencia del tratamiento en las caracterĂsticas del agua de abastecimiento de Logroño
The elusive tidal tails of the Milky Way globular cluster NGC 7099
We present results on the extra-tidal features of the Milky Way globular cluster NGC 7099, using deep gr photometry obtained with the Dark Energy Camera (DECam). We reached nearly 6 mag below the cluster's main sequence (MS) turnoff, so that we dealt with the most suitable candidates to trace any stellar structure located beyond the cluster tidal radius. From star-by-star reddening corrected color-magnitude diagrams (CMDs), we defined four adjacent strips along the MS, for which we built the respective stellar density maps, once the contamination by field stars was properly removed. The resulting, cleaned, field star stellar density maps show a short tidal tail and some scattered debris. Such extra-tidal features are hardly detected when much shallower Gaia DR2 data sets are used and the same CMD field star cleaning procedure is applied. Indeed, by using 2.5 mag below the MS turnoff of the cluster as the faintest limit (G < 20.5 mag), cluster members turned out to be distributed within the cluster's tidal radius, and some hints for field star density variations are found across a circle of radius 3.5° centered on the cluster and with similar CMD features as cluster stars. The proper motion distribution of these stars is distinguishable from that of the cluster, with some superposition, which resembles that of stars located beyond 3.5° from the cluster center.Fil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Carballo Bello, Julio A.. Universidad de Tarapacá; ChileFil: Mora, Marcelo D.. Pontificia Universidad CatĂłlica de Chile; ChileFil: Cenzano, Carolina. Pontificia Universidad CatĂłlica de Chile; ChileFil: Navarrete, Camila. European Southern Observatory Santiago; Chile. Instituto Milenio de AstrofĂsica; ChileFil: Catelan, Márcio. Universidad CatĂłlica de Chile; Chile. Instituto Milenio de AstrofĂsica; Chil
Lipid profiling by electrospray ionization tandem mass spectrometry and the identification of lipid phosphorylation by kinases in potato stolons
There is limited information about the involvement of lipids and esterified fatty acids in signaling pathways during plant development. The purpose of this study was to evaluate the lipid composition and molecular species of potato (Solanum tuberosum L., cv. Spunta) stolons and to identify phosphorylated lipids in the first two developmental stages of tuber formation. Lipid profiling was determined using ESI-MS/MS, a useful method for the determination of the biosynthesis and catabolism of lipids based on their fatty acid composition. The most prevalent compound identified in this study was phosphatidic acid (PA); digalactosyldiacylglycerol (DGDG) was the second most abundant compound. A 34:2 species was identified in PA, phosphatidylcholine (PC), phosphatidylinositol (PI), and phosphatidylethanolamine (PE). The identification of lipid phosphorylation by kinases was revealed by the presence of the phosphorylated lipids. PA was metabolized to diacylglycerol pyrophosphate (DGPP) by phosphatidic acid kinase (PAK). This work establishes a correlation between lipid fatty acid composition and lipid metabolism enzymes at the beginning of tuber formation and is the first report of PAK activity in the early events of potato tuber formation.Fil: Cenzano, Ana MarĂa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; ArgentinaFil: Cantoro, Renata. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones FisiolĂłgicas y EcolĂłgicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de AgronomĂa. Instituto de Investigaciones FisiolĂłgicas y EcolĂłgicas Vinculadas a la Agricultura; ArgentinaFil: Hernández Sotomayor, S. M. Teresa. Centro de InvestigaciĂłn CientĂfica de Yucatán; MĂ©xicoFil: Abdala, Guillermina Irene. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas FisicoquĂmicas y Naturales; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Racagni, Graciela Esther. Universidad Nacional de RĂo Cuarto. Facultad de Ciencias Exactas FisicoquĂmicas y Naturales; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Signatures of tidal disruption in the Milky Way globular cluster NGC 6981 (M72)
We study the outer regions of the Milky Way globular cluster NGC6981 from
publicly available photometry and new Dark Energy Camera (DECam)
observations, both reaching nearly 4 mag below the cluster main sequence (MS)
turnoff. While the data sets reveal the present of extra-tidal features
around the cluster, the much larger field of view of DECam observations allowed
us to identify some other tidal features, which extend from the cluster toward
the opposite direction to the Milky Way center. These cluster structural
features arise from stellar density maps built using MS stars, once the cluster
color-magnitude diagram was cleaned from the contamination of field stars. We
also performed -body simulations in order to help us to understand the
spatial distribution of the extra-tidal debris. The outcomes reveal the
presenceof long trailing and leading tails mostly parallel to the direction of
the cluster velocity vector. We found that the cluster has lost most of its
mass by tidal disruption during its perigalactic passages, that lasted nearly
20 Myr each. Hence, a decrease in the density of escaping stars near the
cluster is expected from our -body simulations, which in turn means that
stronger extra-tidal features could be found out by exploring much larger areas
around NGC6891.Comment: 8 pages, 10 figures. Accepted for publication in Astronomy &
Astrophysic