2,468 research outputs found
Local vs. long-range infection in unidimensional epidemics
We study the effects of local and distance interactions in the unidimensional
contact process (CP). In the model, each site of a lattice is occupied by an
individual, which can be healthy or infected. As in the standard CP, each
infected individual spreads the disease to one of its first-neighbors with rate
, and with unitary rate, it becomes healthy. However, in our model, an
infected individual can transmit the disease to an individual at a distance
apart. This step mimics a vector-mediated transmission. We observe the
host-host interactions do not alter the critical exponents significantly in
comparison to a process with only L\'evy-type interactions. Our results
confirm, numerically, early field-theoretic predictions.Comment: 8 pages, 6 figures, to appear on Frontiers in Physic
Bis(tetraÂphenylÂphosphoÂnium) bisÂ[N-(octylÂsulfonÂyl)dithioÂcarbimato(2–)-κ2 S,S′]Ânickelate(II)
The Ni atom in the title complex, (C24H20P)2[Ni(C9H17NO2S3)2], lies on a twofold axis within a square-planar geometry defined by four S atoms derived from two dithioÂcarbimate dianions, each forming a four-membered chelate ring. A small distortion, described by a deviation of the NiII atom by 0.083 (1) Å from the plane through the four S atoms, and also by the torsion angles about the Ni—S bonds, implies a folded conformation for the chelate ring
Bis(tetraÂphenylÂphosphoÂnium) trisÂ[N-(methylÂsulfonÂyl)dithioÂcarbimato(2−)-κ2 S,S′]stannate(IV)
In the title complex, (C24H20P)2[Sn(C2H3NO2S3)3], the SnIV atom is coordinated by three N-(methylÂsulfonÂyl)dithioÂcarbimate bidentate ligands through the anionic S atoms in a slightly distorted octaÂhedral coordination geometry. There is one half-molÂecule in the asymmetric unit; the complex is located on a crystallographic twofold rotation axis passing through the cation and bisÂecting one of the (non-symmetric) ligands, which appears thus disordered over two sites of equal occupancy. In the crystal structure, weak interÂmolecular C—H⋯O and C—H⋯S interÂactions contribute to the packing stabilization
Rainfall-triggered landslides in the Lisbon region over 2006 and relationships with the North Atlantic Oscillation
Landslides occurred in the Lisbon area during the last 50 years were almost always induced by rainfall and have been used to establish rainfall thresholds for regional landslide activity. In 2006, three new rainfall-triggered landslide events occurred in the study area, namely on the 20 March, the 25–27 October, and the 28 November. Landslide events occurred in March and October 2006 include shallow translational slides and few debris flows, and the corresponding absolute antecedent rainfall was found to be above the threshold for durations ranging from 4 to 10 days. These events also fit the combined threshold of daily precipitation and 5 days calibrated antecedent rainfall values. Likewise the landslide event that took place in late November 2006 includes some slope movements with deeper slip surfaces, when compared with landslides dating from March and October. Moreover, the corresponding absolute antecedent rainfall was also found to be above the 40-day period rainfall threshold.
Here we characterize in detail the short and long-term atmospheric circulation conditions that were responsible for the intense rainfall episodes that have triggered the corresponding landslide events. It is shown that the three rainfall episodes correspond to considerably different synoptic atmospheric patterns, with the March episode being associated to an intense cut-off low system while the October and November episodes appear to be related to more typical Atlantic low pressure systems (and associated fronts) travelling eastwards.
Finally, we analyse the role played by the North Atlantic Oscillation (NAO) during those months marked by landslide activity. It is shown that the NAO index was consistently negative (usually associated with above average precipitation) for the months prior to the landslide events, i.e. between October 2005 and March 2006, and again between August and October 2006.info:eu-repo/semantics/publishedVersio
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