196,042 research outputs found
The Seasonal and Interannual Variability of the Ligurian Sea
No full textUnderstanding the variability of the Ligurian Sea is potentially leading to solve the long standing questions about how deep is the Liguro-Provencal Current (LPC)? What drives the circulation across the Corsica Channel? What are the time scales of this variability and how well can geostrophy describe the circulation across the Ligurian basin?Seven free floating devices called MERMAID have been deployed in the Ligurian Sea from 2012 to 2015, surfacing every 4-5 days on average. The instruments positioning data constituted a valuable source to estimate the LPC depth and speed at 1500 m below the sea surface.The Corsica Channel is a choke point to monitor the exchanges between the Tyrrhenian Sea and Ligurian Sea. The water flux across the Channel has been monitored for more than 30 years, constituting one of the longest world time series. In the present work the water flux from 1985 to 2010 constitutes the focus to relate atmospheric and marine variables in the Ligurian Sea and Tyrrhenian Sea. The study highlights the permanent influence of the atmospheric Sea Surface Pressure (SSP) on the exchange between the two basins and the crucial role of the Sea Level Anomaly (SLA) on the opposite sides of the Corsica Channel. On a seasonal time scale the water flux variability well relates with SSP, SLA, Ekman transport and meridional wind stress. The interannual variability results instead from changes in SLA.The novel discoveries about deep LPC velocities and Corsica Channel transport are useful constraints for Inverse Box Model (IBM). The IBM, has been run for the first time incorporating data collected during 9 cruises. The oceanographic cruises took place from 2002 to 2012. The IBM results shed light on the importance of the Capraia Channel, almost completely absent in literature. The inversions also outlined the Western Corsica Channel current variability neglected in literature. Through the IBM technique, a modern estimation of the Ligurian Sea circulation and geostrophic transport has been generated.This study ultimately contributes to the fundamental knowledge of the Ligurian Sea circulation, implementing state of the art observations and reanalysis data.<br/
Tonic Modulation of GABA Release by Nicotinic Acetylcholine Receptors in Layer V of the Murine Prefrontal Cortex
No full textBy regulating the neocortical excitability, nicotinic acetylcholine receptors (nAChRs) control vigilance and cognition and are implicated in epileptogenesis. Modulation of gamma-aminobutyric acid (GABA) release often accompanies these processes. We studied how nAChRs regulate GABAergic transmission in the murine neocortex with immunocytochemical and patch-clamp methods. The cholinergic fibers densely innervated the somatosensory, visual, motor, and prefrontal cortices (PFC). Laminar distribution was broadly homogeneous, especially in the PFC. The cholinergic terminals were often adjacent to the soma and dendrites of GABAergic interneurons, but well-differentiated synapses were rare. Tonically applied nicotine (1-100 mu M) increased the frequency of spontaneous GABAergic inhibitory postsynaptic currents (IPSCs) on pyramidal neurons in PFC layer V. The contribution of nAChR types was assessed by using 1 mu M dihydro-beta-erythroidine (DH beta E), to block heteromeric nAChRs, and 10 nM methyllycaconitine (MLA), to block homomeric nAChRs. Both inhibitors antagonized the effect of nicotine on IPSCs, suggesting that mixed nAChR types control pyramidal neuron inhibition in layer V. To determine whether nAChRs are expressed on basket cells' terminals, we studied miniature IPSCs (mIPSCs). These were revealed using 0.5 mu M tetrodotoxin and 50 mu M Cd2+ to isolate the GABAergic terminals from the action potential drive. The nicotinic stimulation of mIPSCs was antagonized by DH beta E, but not MLA, indicating that heteromeric nAChRs prevail in GABAergic terminals. Immunocytochemistry confirmed the expression of nAChRs on basket cells' somata and terminals. Finally, when the ionotropic glutamatergic transmission was blocked, nicotine partially inhibited the IPSCs, an effect counteracted by both DH beta E and MLA. Therefore, a fraction of nAChRs are capable of activating GABAergic interneurons that in turn inhibit other GABAergic interneurons, thereby reducing the IPSCs. We conclude that heteromeric nAChRs control GABA release presynaptically, whereas mixed nAChRs regulate both excitation and inhibition of interneurons, the balance depending on the overall glutamatergic drive
La scheda interattiva di INNOVance per prodotti in laterizio
No full textAnche per i laterizi la scheda tecnica di prodotto, sviluppata nell’ambito del pro getto INNOVance, assume un ruolo fondamentale a supporto della progettazione e della gestione delle informazioni nelle diverse fasi del processo edilizio. L’insieme di dati contenuti in ciascuna scheda sarà associato alla rappresentazione di oggetti innovativi di tipo BIM 'Building Information Model
Phosphorylation of sodium channels mediated by protein kinase-C modulates inhibition by topiramate of tetrodotoxin-sensitive transient sodium current
No full textTopiramate is a novel anticonvulsant known to modulate the activity of several ligand- and voltage-gated ion channels in neurons. The mechanism of action of topiramate, at a molecular level, is still unclear, but the phosphorylation state of the channel/receptor seems to be a factor that is able to influence its activity. We investigated the consequences of phosphorylation of the sodium channel on the effect of topiramate on tetrodotoxin (TTX)-sensitive transient Na(+) current (I(NaT))
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Rapid response to climate change in a marginal sea
No full textThe Mediterranean Sea is a mid-latitude marginal sea, particularly responsive to climate change as reported by recent studies. The Sicily Channel is a choke point separating the sea in two main basins, the Eastern Mediterranean Sea and the Western Mediterranean Sea. Here, we report and analyse a long-term record (1993–2016) of the thermohaline properties of the Intermediate Water that crosses the Sicily Channel, showing increasing temperature and salinity trends much stronger than those observed at intermediate depths in the global ocean. We investigate the causes of the observed trends and in particular determine the role of a changing climate over the Eastern Mediterranean, where the Intermediate Water is formed. The long-term Sicily record reveals how fast the response to climate change can be in a marginal sea like the Mediterranean Sea compared to the global ocean, and demonstrates the essential role of long time series in the ocean
Empowering e-services through the Semantic Web
No full textThis article illustrates how to enhance data interoperability among Public Administrations (PPAA) by leveraging the publication of e-services based on Semantic Web (SW) technologies such as ontologies, controlled vocabularies, and data schemas, which, through standard languages like OWL, RDF, and SPARQL, ensure harmonization, integrability, and unique semantics for representing administrative data. Furthermore, the potential benefits of implementing semantic e-services through Ontology-based Data Management (OBDM), a data governance methodology that enables data services through ontologies, decoupling their implementation from the physical data sources of PPAA, are discussed. Additionally, the advantages for PPAA of data exchange through semantic e-services utilizing concepts published in the Schema platform, developed by the National Data Catalog project funded through PNRR funds, will be highlighted in the presented use case
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Layer-specific properties of the persistent sodium current in sensorimotor cortex
No full textWe evaluated the characteristics of the persistent sodium current (I(NaP)) in pyramidal neurons of layers II/III and V in slices of rat sensorimotor cortex using whole cell patch-clamp recordings. In both layers, I(NaP) began activating around -60 mV and was half-activated at -43 mV. The I(NaP) peak amplitude and density were significantly higher in layer V. The voltage-dependent I(NaP) steady-state inactivation occurred at potentials that were significantly more positive in layer V (V(1/2): -42.3 +/- 1.1 mV) than in layer II/III (V(1/2): -46.8 +/- 1.6 mV). In both layers, a current fraction corresponding to about 25% of the maximal peak amplitude did not inactivate. The time course of I(NaP) inactivation and recovery from inactivation could be fitted with a biexponential function. In layer V pyramidal neurons the faster time constant of development of inactivation had variable values, ranging from 158.0 to 1,133.8 ms, but it was on average significantly slower than that in layer II/III (425.9 +/- 80.5 vs. 145.8 +/- 18.2 ms). In both layers, I(NaP) did not completely inactivate even with very long conditioning depolarizations (40 s at -10 mV). Recovery from inactivation was similar in the two layers. Layer V intrinsically bursting and regular spiking nonadapting neurons showed particularly prolonged depolarized plateau potentials when Ca2+ and K+ currents were blocked and slower early phase of I(NaP) development of inactivation. The biexponential kinetics characterizing the time-dependent inactivation of I(NaP) in layers II/III and V indicates a complex inactivating process that is incomplete, allowing a residual "persistent" current fraction that does not inactivate. Moreover, our data indicate that I(NaP) has uneven inactivation properties in pyramidal neurons of different layers of rat sensorimotor cortex. The higher current density, the rightward shifted voltage dependency of inactivation as well the slower kinetics of inactivation characterizing I(NaP) in layer V with respect to layer II/III pyramidal neurons may play a significant role in their ability to fire recurrent action potential bursts, as well in the high susceptibility to generate epileptic events
Expression of the K-Cl co-transporter KCC2 in cerebral cortex and thalamus during murine postnatal development
No full textIn the adult central nervous system GABA mediates fast inhibitory transmis- sion, whereas during development it is an excitatory transmitter and a trophic factor involved in controlling morphogenesis (Ben-Ari, 2002). This funcional shift occurs as a result of a progressively increasing expression of the KCC2 cotransporter, the major chloride extruder in mature neurons. In several pathological conditions associated with hyperexcitability, such as epilepsy, suppression of KCC2 may contribute to alter the balance of excitation and inhibition (Chamma et al., 2012), especially during neu- ral circuit formation. On these basis we studied the expression of KCC2 in two rep- resentative areas of neocortex, somatosensory and prefrontal (PFC), and in the dor- sal thalamus, at different postnatal stages by western blot and immunocytochemical analysis. Our results show conspicuous expression of KCC2 at postnatal day 0 (P0) in the neuropil of thalamic nuclei, except the reticular nucleus. Lower expression is observed in cortical areas, with PFC displaying the lowest signal. In the first postna- tal week, KCC2 is mainly localized in the cell bodies of cortical GABAergic neurons and pyramidal cells. After P7, it is gradually distributed in the membranes of the whole somatodendritic compartment, becoming prevalent in the neuropil by P14. In the adult cortices an intense labelling for KCC2 is observed in the supragranular lay- ers if compared with the moderate expression of layer V; in the thalamus the anterior and sensory nuclear groups show the highest immunoreactivity. Overall, our results suggest a complex spatiotemporal pattern of KCC2 expression in the murine prosen- cephalon that needs to be related not only with inhibitory transmission but also with the different arrangements of neuronal circuits in cortical and thalamic subregions
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