The Valuation of Mortgage Backed Securities with Stochastic Probabilities of Default and Prepayment

The aim of this paper is to provide a new approach to project the Mortgage Backed Securities (MBS) cash flows in emerging markets where collateral information is limited, wrong or scarce. Under this framework, we use the Cox Process to model stochastic probabilities of prepayment and default. The model deals with general intensity dynamics and is applied to the starting MBS Mexican market.Mortgage valuation, MBS prepayment, MBS default, MBS curtailment, Cox Process.

Extended-spectrum beta-lactamases-producing <i>Escherichia coli</i> in common vampire bats <i>Desmodus rotundus</i> and livestock in Peru

Antibiotic resistance mediated by bacterial production of extended‐spectrum beta‐lactamase (ESBL) is a global threat to public health. ESBL resistance is most commonly hospital‐acquired; however, infections acquired outside of hospital settings have raised concerns over the role of livestock and wildlife in the zoonotic spread of ESBL‐producing bacteria. Only limited data are available on the circulation of ESBL‐producing bacteria in animals. Here, we report ESBL‐producing Escherichia coli in wild common vampire bats Desmodus rotundus and livestock near Lima, Peru. Molecular analyses revealed that most of this resistance resulted from the expression of blaCTX‐M‐15 genes carried by plasmids, which are disseminating worldwide in hospital settings and have also been observed in healthy children of Peru. Multilocus sequence typing showed a diverse pool of E. coli strains carrying this resistance that were not always host species‐specific, suggesting sharing of strains between species or infection from a common source. This study shows widespread ESBL resistance in wild and domestic animals, supporting animal communities as a potential source of resistance. Future work is needed to elucidate the role of bats in the dissemination of antibiotic‐resistant strains of public health importance and to understand the origin of the observed resistance

Thermal radiation in non-static curved spacetimes: quantum mechanical path integrals and configuration space topology

A quantum mechanical path integral derivation is given of a thermal propagator in non-static Gui spacetime. The thermal nature of the propagator is understood in terms of homotopically non-trivial paths in the configuration space appropriate to tortoise coordinates. The connection to thermal emission from collapsing black holes is discussed.Comment: 20 pages, major revised version, 9 figures, new titl

Crystallization and preliminary X-ray analysis of the ternary complex of procarboxypeptidase A from bovine pancreas

AbstractThe ternary complex of procarboxypeptidase A, chymotrypsinogen C and proproteinase E from bovine pancreas has been crystallized using the sitting drop vapour diffusion method. The success in obtaining crystals has been found to be critically dependent on the prevention of autolysis of the complex. In preliminary stages, crystals twinned by merohedry were obtained from a solution containing MgCl2 and polyethylenglycol 400 as precipitating agent. Later on, untwinned ones could be grown employing CaCl2 instead of MgCl2. These latter crystals belong to the rhombohedral system and to the spacegroup R3 with cell dimensions a = b = 188.5 Å and c = 82.5 Å. Consideration of the possible values of Vm accounts for the presence of one ternary complex molecule-oligomere per asymmetric unit. The crystals diffract beyond 2.6 Å resolution and are suitable for X-ray analysis

Nested Methodological Approaches for Cluster Policy Evaluation: An Application to the Basque Country

This paper explores the evaluation of cluster policies designed to support cooperation and networking. It examines the case of the long-running Basque policy, where support is provided for ‘cluster associations’. It first examines empirically the effects of the cluster associations on firm productivity performance, alongside other variables including agglomeration and firm behavioural characteristics. The results provide some weak evidence for the existence of additionality associated with the policy. This empirical work is complemented with context-specific knowledge of the policy in question to show that the nesting of both empirical and contextual approaches is crucial for effectively evaluating such policies

A toxicokinetic study reflecting the absorption, distribution, metabolism and excretion of deoxynivalenol in broiler chickens

To identify the specific biomarkers of exposure of DON in chickens, a toxicokinetic study was performed via oral or intravenous application of deoxynivalenol (DON). Doses of 0.75 and 2.25 mg DON/kg of body weight (BW) were administrated intravenously or orally to the chickens. Next, blood samples were collected at several time points and plasma was obtained. Liquid chromatography–tandem massspectrometry (LC–MS/MS) was used to quantify plasma levels of DON and its metabolite DON-3- sulphate (DON-3S). A non-compartmental analysis was performed to study the main toxicokinetic parameters after intravenous or oral application of the toxin. Regarding oral administration, DON plasma level was below the limit of detection (LOD) of the method (1.5 ng/mL) and DON-3S could not be identified. After intravenous administration of DON at 0.75 and 2.25 mg DON/kg BW, the elimination half-life was 57.1 and 47.7 min, respectively, indicating the rapid elimination of DON. The metabolite DON-3S was found in plasma of broilers exposed to DON intravenously. The absence of DON in chicken plasma after oral bolus application suggests the low absorption of this mycotoxin. The presence of DON-3S in plasma indicates that this metabolite could be the appropriate biomarker of DON exposure in chickens

Proceso automático para la medida de las reflectancias. 1.- Descripción preliminar

To calculated the physical constant, n, k, from the reflectance measurements in two different media of known refractive indices, it is necessary to apply a stadistic criterion that represents to obtein a great numher of experimental data. The preliniinary description of the method used shows how et is simplified the calculation of the values of n, k, from the experimental data of reflectance