Chemical Linkage to Injected Tissues Is a Distinctive Property of Oxidized Avidin

We recently reported that the oxidized avidin, named AvidinOX®, resides for weeks within injected tissues as a consequence of the formation of Schiff's bases between its aldehyde groups and tissue protein amino groups. We also showed, in a mouse pre-clinical model, the usefulness of AvidinOX for the delivery of radiolabeled biotin to inoperable tumors. Taking into account that AvidinOX is the first oxidized glycoprotein known to chemically link to injected tissues, we tested in the mouse a panel of additional oxidized glycoproteins, with the aim of investigating the phenomenon. We produced oxidized ovalbumin and mannosylated streptavidin which share with avidin glycosylation pattern and tetrameric structure, respectively and found that neither of them linked significantly to cells in vitro nor to injected tissues in vivo, despite the presence of functional aldehyde groups. The study, extended to additional oxidized glycoproteins, showed that the in vivo chemical conjugation is a distinctive property of the oxidized avidin. Relevance of the high cationic charge of avidin into the stable linkage of AvidinOX to tissues is demonstrated as the oxidized acetylated avidin lost the property. Plasmon resonance on matrix proteins and cellular impedance analyses showed in vitro that avidin exhibits a peculiar interaction with proteins and cells that allows the formation of highly stable Schiff's bases, after oxidation

Error Rate Estimation for DS-IR and DS-UWB over Frequency Selective Channels

We consider a single user Direct Sequence Impulse Radio (DS-IR) system operating with a QPSK constellation over a deterministic, frequency selective channel and affected by Additive White Gaussian Noise (AWGN). We present a method to obtain a fast and accurate estimation of the Symbol Error Rate (SER) when the receiver is a correlation receiver with perfect synchronization and channel knowledge. The method is based on the estimation of the Inter Symbol Interference (ISI) distribution by means of the Characteristic Function (CF) approach. The results also apply to Direct Sequence Ultra Wideband (DS-UWB) modulation since it is a special case of DS-IR. The accuracy of the method is verified by comparing the SER prediction with that obtained by means of Monte Carlo (MC) simulation

A BEHAVIOURAL CHOICE MODEL FOR THE EVALUATION OF RAILWAY SUPPLY AND PRICING POLICIES

The simulation of modal choice for intercity trips has been carried out by several authors using a variety of different models. Traditionally, the problem has been treated by a static representation of the system, modeling transport services, such as rail or bus, as service lines with an approach similar to the urban transit services one. These models consider time-averaged attributes such as frequencies, travel times, and prices and allow to obtain average flows and revenues for each line, without any possibility to estimate values for single trains or buses. This approach does not seem to be the best simulation tool to support operational market-oriented decisions such as service schedule or time-varying price policies. This paper presents a choice model that can be used to simulate impacts of variations in medium-long distance railway service characteristics on user choice of service type, run, and class. The model, based on a nested-logit service/run/class/access-egress mode choice model, explicitly takes into account the desired departure time and related early/late schedule delay penalities

A doubly dynamic schedule-based assignment model for transit networks

In order to improve the performances of transit modeling and in particular to assess the effects of the introduction of ITS technologies, which imply substantial changes in user behavior, in the last 10 years transit path choice and assignment models that use a schedulebased approach, instead of the traditional frequency-based one, have been developed. This paper presents a schedule-based path choice model for high-frequency transit networks, which allows us to consider the evolution in time of transit services, both within-day and day-to-day, as well as the day-to-day learning process of attributes by which users choose. On the basis of this path choice model a dynamic process assignment model, both within-day and day-to-day (from which the term "doubly dynamic" derives), was developed and tested on a realistically sized network to verify its applicability for operations planning

Distribuzione urbana delle merci tramite ferrovia regionale: un’applicazione test nella penisola Sorrentina

In questa nota è affrontato il problema della distribuzione delle merci utilizzando per l’accesso all’area metropolitana le presenti infrastrutture ferroviarie. È descritta una metodologia per l’analisi della fattibilità tecnico-economica del sistema di progetto che prevede la messa a punto di un sistema di modelli per la stima della domanda merci di prodotti finali; è sinteticamente descritta l’applicazione alla penisola Sorrentina