Which Bank is the "Central" Bank? An Application of Markov Theory to the Canadian Large Value Transfer System

We use a method similar to Google's PageRank procedure to rank banks in the Canadian Large Value Transfer System (LVTS). Along the way we obtain estimates of the payment processing speeds for the individual banks. These differences in processing speeds are essential for explaining why observed daily distributions of liquidity differ from the initial distributions, which are determined by the credit limits selected by banks.Payment, clearing, and settlement systems

Congestion and cascades in payment systems

We develop a parsimonious model of the interbank payment system to study congestion and the role of liquidity markets in alleviating congestion. The model incorporates an endogenous instruction arrival process, scale-free topology of payments between banks, fixed total liquidity that limits banks’ capacity to process arriving instructions, and a global market that distributes liquidity. We find that at low liquidity, the system becomes congested and payment settlement loses correlation with payment instruction arrival, becoming coupled across the network. The onset of congestion is evidently related to the relative values of three characteristic times: the time for banks’ net position to return to zero, the time for banks to exhaust their liquidity endowments, and the liquidity market relaxation time. In the congested regime, settlement takes place in cascades having a characteristic size. A global liquidity market substantially diminishes congestion, requiring only a small fraction of the payment-induced liquidity flow to achieve strong beneficial effects

Evaluation of susceptibility of pear and plum varieties and rootstocks to Ca. P. pyri and Ca. P. prunorum using Real-Time PCR

Real-time PCR was used to quantify phytoplasma concentration in fifty inoculated trees from five Prunus rootstocks and in forty-eight symptomatic pear and Japanese plum trees from orchards. Seasonal fluctuation of Ca. P. prunorum in different Prunus rootstocks, over three years, showed that the highest percentage detected by nested-PCR was in the ‘Garnem’ rootstock on nearly all sampling dates. Intra-varietal differences were also observed. Phytoplasma titer could be estimated by real time PCR in some trees of the rootstocks ‘Garnem’, ‘Barrier’, ‘GF-677’ and ‘Marianna’, and ranged from 4.7x105 to 3.18x109 phytoplasmas per gram of tissue. Quantification by real-time PCR was not possible in the ‘Cadaman’ trees analyzed, probably due to a lower phytoplasma titer in this variety. Samples from infected trees from commercial plots had different phytoplasma concentration and detection percentage depending on the variety, both being lower in ‘Fortune’ and ‘606’ Japanese plum and in ‘Blanquilla’ pear trees.Keywords: Candidatus Phytoplasma pyri, Candidatus Phytoplasma prunorum, real time PCR, detectio

The topology of interbank payment flows

We explore the network topology of the interbank payments transferred between commercial banks over the Fedwire® Funds Service. We find that the network is compact despite low connectivity. The network includes a tightly connected core of money-center banks to which all other banks connect. The degree distribution is scale-free over a substantial range. We find that the properties of the network changed considerably in the immediate aftermath of the attacks of September 11, 2001

Bioavailability, mobility and leaching of phosphorus in a Mediterranean agricultural soil (ne Spain) amended with different doses of biosolids

The precipitation of sparingly soluble calcium phosphate in calcareous soils decreases the bioavailability of macronutrients, which makes their addition by way of fertilisers necessary. Sludge resulting from treating urban wastewater does not only provide significant amounts of phosphorus, but also helps lower the pH, thus increasing its bioavailability. The loss of part of soil nutrients due to irrigation or rain can contaminate groundwater. In order to assess the movement of phosphorus, a experiment was conducted on percolation columns, to which different doses of wastes were applied. The pH decreased by as much as 0.89 units, as well as the assimilable and soluble P, in intervals of 20 cm of depth, obtaining maximum values of 254 mg P kg-1 and 1455 lg P kg-1 respectively, and the P present in the leached water collected, which did not surpass 95 lg PL-1. The intent was to learn which was the majoritarian inorganic formed crystalline phase that immobilised the movement of phosphorus through the percolation column. The results obtained by the diffraction of X-rays are not conclusive, although they point to the formation of octacalcium phosphate. The diffractograms of the studied samples have similar diffraction lines to those of apatites

Multisource data verification of a weather radar surface precipitation type product

Póster presentado en: 10th European Conference on Radar in Meteorology and Hydrology celebrado en Wageningen, Países Bajos, del 1 al 6 de julio de 2018.This study was partly supported by projects CGL2015-65627-C3-2-R (MINECO/FEDER), CGL2016-81828-REDT (MINECO) and DI065/2017 (Industrial Doctorate Programme of the Regional Government of Catalonia

A Study of Competing Designs for a Liquidity-Saving Mechanism

We study two designs for a liquidity-saving mechanism (LSM), a queuing arrangement used with an interbank settlement system. We consider an environment where banks are subjected to liquidity shocks. Banks must make the decision to send, queue, or delay their payments after observing a noisy signal of the shock. With a balance-reactive LSM, banks can set a balance threshold below which payments are not released from the queue. Banks can choose their threshold such that the release of a payment from the queue is conditional on the liquidity shock. With a receipt-reactive LSM, a payment is released from the queue if an offsetting payment is received, regardless of the liquidity shock. We find that these two designs have opposite effects on different types of payments. Payments that are costly to delay will be settled at least as early, or earlier, with a receipt-reactive LSM. Payments that are not costly to delay will always be delayed with a receipt-reactive LSM, while some of them will be queued and settled early with a balance-reactive LSM. We also show that parameter values will determine which system provides higher welfare

Fantappie's group as an extension of special relativity on Cantorian space-time

In this paper we will analyze the Fantappie group and its properties in connection with Cantorian space-time. Our attention will be focused on the possibility of extending special relativity. The cosmological consequences of such extension appear relevant, since thanks to the Fantappie group, the model of the Big Bang and that of stationary state become compatible. In particular, if we abandon the idea of the existence of only one time gauge, since we do not see the whole Universe but only a projection, the two models become compatible. In the end we will see the effects of the projective fractal geometry also on the galactic and extra-galactic dynamics.Comment: 14 pages, accepted in Chaos, Solitons and Fractal