Approximate solution to a hybrid model with stochastic volatility: a singular-perturbation strategy

We study a hybrid model of Schobel-Zhu-Hull-White-type from a singular-perturbation-analysis perspective. The merit of the paper is twofold: On one hand, we find boundary conditions for the deterministic non-linear degenerate parabolic partial differential equation for the evolution of the stock price. On the other hand, we combine two-scales regular- and singular-perturbation techniques to find an approximate solution to the pricing PDE. The aim is to produce an expression that can be evaluated numerically very fast

Polyhexamethylene Biguanide and Nadifloxacin Self-Assembled Nanoparticles: Antimicrobial Effects against Intracellular Methicillin-Resistant Staphylococcus aureus

The treatment of skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA) remains a challenge, partly due to localization of the bacteria inside the host’s cells, where antimicrobial penetration and efficacy is limited. We formulated the cationic polymer polyhexamethylene biguanide (PHMB) with the topical antibiotic nadifloxacin and tested the activities against intracellular MRSA in infected keratinocytes. The PHMB/nadifloxacin nanoparticles displayed a size of 291.3 ± 89.6 nm, polydispersity index of 0.35 ± 0.04, zeta potential of +20.2 ± 4.8 mV, and drug encapsulation efficiency of 58.25 ± 3.4%. The nanoparticles killed intracellular MRSA, and relative to free polymer or drugs used separately or together, the nanoparticles displayed reduced toxicity and improved host cell recovery. Together, these findings show that PHMB/nadifloxacin nanoparticles are effective against intracellular bacteria and could be further developed for the treatment of skin and soft tissue infections

Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria : The Role of Environmental and Climatic Risk Factors on the Distribution of Disease.

Funding: Jennifer L Smith was supported by the International Trachoma Initiative through a grant from the Bill and Melinda Gates Foundation. Anthony Solomon is a Wellcome Trust Intermediate Clinical Fellow (098521). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Infrared spectroscopic studies of novel hydroxybisphosphonates and molecular modelling of their interaction with hydroxyapatite

Bisphosphonates (BPs) are a class of drugs widely used in the treatment of several metabolic bone disorders associated with increased bone resorption, including osteoporosis, Paget’s disease and metastic bone disease [1]. Although BPs can directly inhibit the cellular activity of osteoclasts, their ability to adsorb to bone mineral is also an important factor in determining their potency and duration of action [2]. In this study, we performed a molecular modelling analysis, by molecular mechanics, of the molecular structures of hydroxy(1H-indazol-3-yl)methylenediphosphonic acid (BP1; Figure 1a) and hydroxy(1-methyl-1H-indazol-3-yl)methylenediphosphonic acid (BP2; Figure 1b) and examined their interactions with hydroxyapatite (HA) by energy-minimising 50 different orientations for judiciously selected low energy conformers of each ligand at 10 Å from the mineral surface. We also calculated the vibrational spectra for each BP with semiempirical methods and compared then with FTIR spectra obtained experimentaly. The calculated interaction energies of the studied BPs with HA suggests that BP2 interacts stronger with hydroxyapatite than BP1. These results are in agreement with in vitro and in vivo studies of the 153Sm-BPs complexes. Complex 153Sm-BP2 showed, in vitro, higher HA binding than complex 153Sm-BP1. In vivo studies showed different farmacokinetics parameters with complex 153Sm-BP2 presenting initial higher levels of bone uptake than complex 153Sm-BP1, which concentration is increasing during the 24 h period studied

Fine mapping of the hereditary haemorrhagic telangiectasia (HHT)3 locus on chromosome 5 excludes VE-Cadherin-2, Sprouty4 and other interval genes

BACKGROUND: There is significant interest in new loci for the inherited condition hereditary haemorrhagic telangiectasia (HHT) because the known disease genes encode proteins involved in vascular transforming growth factor (TGF)-beta signalling pathways, and the disease phenotype appears to be unmasked or provoked by angiogenesis in man and animal models. In a previous study, we mapped a new locus for HHT (HHT3) to a 5.7 Mb region of chromosome 5. Some of the polymorphic markers used had been uninformative in key recombinant individuals, leaving two potentially excludable regions, one of which contained loci for attractive candidate genes encoding VE Cadherin-2, Sprouty4 and FGF1, proteins involved in angiogenesis. METHODS: Extended analyses in the interval-defining pedigree were performed using informative genomic sequence variants identified during candidate gene sequencing. These variants were amplified by polymerase chain reaction; sequenced on an ABI 3730xl, and analysed using FinchTV V1.4.0 software. RESULTS: Informative genomic sequence variants were used to construct haplotypes permitting more precise citing of recombination breakpoints. These reduced the uninformative centromeric region from 141.2-144 Mb to between 141.9-142.6 Mb, and the uninformative telomeric region from 145.2-146.9 Mb to between 146.1-146.4 Mb. CONCLUSIONS: The HHT3 interval on chromosome 5 was reduced to 4.5 Mb excluding 30% of the coding genes in the original HHT3 interval. Strong candidates VE-cadherin-2 and Sprouty4 cannot be HHT3

Acceptance conditions in automated negotiation

In every negotiation with a deadline, one of the negotiating parties has to accept an offer to avoid a break off. A break off is usually an undesirable outcome for both parties, therefore it is important that a negotiator employs a proficient mechanism to decide under which conditions to accept. When designing such conditions one is faced with the acceptance dilemma: accepting the current offer may be suboptimal, as better offers may still be presented. On the other hand, accepting too late may prevent an agreement from being reached, resulting in a break off with no gain for either party. Motivated by the challenges of bilateral negotiations between automated agents and by the results and insights of the automated negotiating agents competition (ANAC), we classify and compare state-of-the-art generic acceptance conditions. We focus on decoupled acceptance conditions, i.e. conditions that do not depend on the bidding strategy that is used. We performed extensive experiments to compare the performance of acceptance conditions in combination with a broad range of bidding strategies and negotiation domains. Furthermore we propose new acceptance conditions and we demonstrate that they outperform the other conditions that we study. In particular, it is shown that they outperform the standard acceptance condition of comparing the current offer with the offer the agent is ready to send out. We also provide insight in to why some conditions work better than others and investigate correlations between the properties of the negotiation environment and the efficacy of acceptance condition