Two-Way Protocol with Imperfect Devices

The security of a deterministic quantum scheme for communication, namely the LM05 [1], is studied in presence of a lossy channel under the assumption of imperfect generation and detection of single photons. It is shown that the scheme allows for a rate of distillable secure bits higher than that pertaining to BB84 [2]. We report on a first implementation of LM05 with weak pulses.     

Good teaching inputs do not correspond to desired responses in ecological neural networks

In this paper we analyze how supervised learning occurs in ecological neural networks, i.e. networks that interact with an autonomous external environment and, therefore, at least partially determine with their behavior their own input. Using an evolutionary method for selecting good teaching inputs we surprisingly find that to obtain a desired outputX it is better to use a teaching input different fromX. To explain this fact we claim that teaching inputs in ecological networks have two different effects: (a) to reduce the discrepancy between the actual output of the network and the teaching input, (b) to modify the network's behavior and, as a consequence, the network's learning experiences. Evolved teaching inputs appear to represent a compromise between these two needs. We finally show that evolved teaching inputs that are allowed to change during the learning process function differently at different stages of learning, first giving more weight to (b) and, later on, to (a).     

On-Line LC-GC for the Analysis of the Minor Components in Edible Oils and Fats – The Direct Method Involving Silylation

The previous on-line LC-GC method for the direct analysis of the minor components in oils and fats (without cleavage of esters) was modified: The free alcohols/sterols were silylated instead of acylated, and the LC fraction transferred to GC is widened to range from the beginning of the LC chromatogram up to the sterol esters. Silylation eliminated the problem that acylation may esterify some free alcohols with free fatty acids from the oil if the oil or fat is of high acidity. Widening of the LC fraction to include squalene and the tocopherols added information to that previously obtained.     

Radiolabeled nucleoside analogs in cancer diagnosis and therapy

Radiolabeled nucleosides, specifically 5-iodo-2'-deoxyuridine (IUdR) radioiodinated with the Auger-electronemitting 123I or 125I, have been shown to produce extensive DNA damage in mammalian cell systems in vitro. Such nucleosides are cycle-dependent agents that are taken up by mitotically dividing cells in the S phase of the cell cycle. The degree of damage that occurs is related to the fact that these nucleosides bind covalently to DNA bringing the decaying Augerelectron-emitting radionuclide in close proximity to the genome. The use of these radiohalogenated nucleosides in vivo is associated with several problems. The first relates to their extremely short biologic half-life in blood (T1/2 of minutes in humans). The second involves achieving therapeutic ratios in tumor cells in the face of efficient hepatic dehalogenation. The third concerns the uptake of these radiopharmaceuticals by actively proliferating normal cell renewal systems, thus potentially causing toxic side effects. The fourth, one shared with other cycle-dependent drugs, relates to the matter of labeling the whole tumor cell population. To facilitate targeting to tumors, investigators have been examining the direct introduction of these agents into the targeted area or into an arterial blood supply that immediately precedes the target. For example, radiopharmaceutical administration could be intracavitary (bladder, spinal fluid, peritoneum), intralesional (brain tumor, breast mass) or intra-arterial (liver, pancreas). In all these situations, the following conditions must be met: (a) once within the vicinity of the tumor the agent can freely diffuse through the tissues and is selectively taken up by cancerous cells; (b) once the agent has left the target area it is converted quickly into a nontoxic form and/or excreted from the body; and finally, (c) the biologic behavior of the agent is not altered by repeated injections. We report herein our experience and that of others with [123I/125I/131I]IUdR in cultured cells, animal tumor-model systems, and patients. In vitro, DNA incorporation of 123I- and 125I-labeled IUdR leads to an exponential decrease in cell survival (no shoulder on the survival curve). However, the total number of decays needed to produce a given lethal effect with [123I]IUdR is approximately twice that required with [125I]IUdR. In vivo, the scintigraphic and antineoplastic capabilities of radioiodinated IUdR have been demonstrated in an intraperitoneal murine ovarian tumor model following intraperitoneal injection; in an intracerebral rat gliosarcoma model after intracranial administration; in an intrathecal rat gliosarcoma model after intrathecal infusion; and in a rat transitional cell bladder cancer model following intravesicular infusion. [123I]IUdR, [125I]IUdR, and/or [131I]IUdR have been administered to patients with brain, breast, colorectal, or gastrointestinal cancers (intratumorally); ovarian cancer (intraperitoneally); bladder cancer (intravesically); liver metastases from colorectal cancer (through the hepatic artery, permanent intra-arterial catheter). These studies have confirmed the observations made in animal models. The data indicate that 5-iodo-2'-deoxyuridine radiolabeled with an Auger electron emitter (123I or 125I) may be a useful agent for the scintigraphic diagnosis and/or therapy of neoplastic diseases that are accessible to direct radiopharmaceutical administration. This radiopharmaceutical should serve as a prototype for, and facilitate the development of, other radiolabeled nucleoside analogs. Further investigations are certainly warranted.     

Techniques for the mechanical characterisation of civil structures

Broadly speaking, structural defects include all those changes affecting a structure so that its behaviour is no longer in keeping with its intended use characteristics or differs from the behaviour it was originally designed for. In recent years, damage recognition and location methods, relying on the measurement of parameters that are indicative of a structure's mechanical behaviour, have benefitted from the introduction of innovative approaches, which make it possible to process and correlate an unprecedented wealth of measurble data. The aim of this work is to illustrate the basic problems associated with the different methods used for structural identification (parametric and non-parametric, linear and non-linear, with known and unknown inputs, etc.) and to report on some interesting applications for civil structural diagnosis.     

Focal Ischemic Injury to the Early Neonatal Rat Brain Models Cognitive and Motor Deficits with Associated Histopathological Outcomes Relevant to Human Neonatal Brain Injury

Neonatal arterial ischemic stroke is one of the more severe birth complications. The injury can result in extensive neurological damage and is robustly associated with later diagnoses of cerebral palsy (CP). An important part of efforts to develop new therapies include the on-going refinement and understanding of animal models that capture relevant clinical features of neonatal brain injury leading to CP. The potent vasoconstrictor peptide, Endothelin-1 (ET-1), has previously been utilised in animal models to reduce local blood flow to levels that mimic ischemic stroke. Our previous work in this area has shown that it is an effective and technically simple approach for modelling ischemic injury at very early neonatal ages, resulting in stable deficits in motor function. Here, we aimed to extend this model to also examine the impact on cognitive function. We show that focal delivery of ET-1 to the cortex of Sprague Dawley rats on postnatal day 0 (P0) resulted in impaired learning in a touchscreen-based test of visual discrimination and correlated with important clinical features of CP including damage to large white matter structures.     

Quantification of secondary structure prediction improvement using multiple alignments

The use of multiple sequence alignments for secondary structurepredictions is analysed. Seven different protein families, containingonly sequences of known structure, were considered to providea range of alignment and prediction conditions. Using alignmentsobtained by spatial superposition of main chain atoms in knowntertiary protein structures allowed a mean of 8% in secondarystructure prediction accuracy, when compared to those obtainedfrom the individual sequences. Substitution of these alignmentsby those determined directly from an automated sequence alignmentalgorithm showed variations in the prediction accuracy whichcorrelated with the quality of the multiple alignments and distanceof the primary sequence. Secondary structure predictions canbe reliably improved using alignments from an automatic alignmentprocedure with a mean increase of 6.87percnt;, giving an overallprediction accuracy of 68.5%, if there is a minimum of 25% sequenceidentity between all sequences in a family.     

Network Externalities,Incumbent’s Competitive Advantage and the Degree of Openness of Software Start-Ups

This paper proposes a formal model that analyzes the degree of openness chosen by start-ups when entering the software industry. In line with the literature, we label as degree of openness the extent to which software start-ups mix open source (OS) and proprietary solutions in the portfolio of software products they offer. We relate the choice of the degree of openness to two key characteristics of the market segments in which software start-ups operate: the strength of the network externalities and the competitive advantage of the incumbent. Specifically, by modelling (price) competition between an incumbent and an entrant in two ways, i.e., the entrant is price-setter or price-taker, we derive the necessary condition(s) in terms of the strength of network externalities for observing the adoption of a business model that comprises the offering of both proprietary and OS solutions by the entrant (i.e., hybrid business model). Then, we highlight that, if a hybrid business model is the choice, the degree of openness chosen in equilibrium increases along with both the strength of the network externalities and the competitive advantage of the incumbent. This result holds indifferently whether the software start-up is modelled as a price-setter or a price-taker. An empirical test run on a sample of European start-ups in the software industry supports these theoretical predictions.     

Regional Climate Simulations on EU-INDIA Grid Infrastructures: Methodologies and Performance

In this paper, we present a possible approach to use different Grid infrastructures across Europe and India for regional climate simulations and discuss in details the advantages and limitations in using them. The application taken into consideration is the Regional Climate Model RegCM4, which has been recently re-written for making it more efficient and easier to be fully exploited on any kind of computational infrastructure. We describe here the methods applied to port this package on the Grid infrastructures made available by the EU-IndiaGrid project. We also discuss different approaches, the way to run the model on both European and Indian infrastructures and our promising approach to deal with data management issues. Use of RegCM on Grid infrastructure has further been compared with that on HPC resources. The domain worked upon for these tests is the South-Asia CORDEX domain, which is of great importance for the Indian Summer Monsoon. Our final conclusion is that, for certain class of experiments, RegCM4 model can be efficiently and easily integrated on Grid infrastructures, by means of the procedures described in this paper.     

A voltammetric study concerning the structural stability of Li-overstoichiometric Mg-doped LiCoO2 powders

The effect of Mg-doping and Li overstoichiometry on the structural stability of LiCoO₂ powders has been investigated with emphasis to voltammetric properties. Microparticle cyclic voltammetry (CV) conducted in caustic NaOH to best simulate a non-aqueous electrolyte shows a marked improvement of the structure stability of doped LiCoO₂. In contrast to the unsubstituted LiCoO₂ sample which shows voltammetric peaks associated to the well-known two-phase domain and monoclinic distortion reactions, in Li_1.08Mg_0.06CoO₂, LiMg_0.06CoO₂ and Li_1.08CoO₂ samples these peaks are strongly suppressed providing direct evidence for the existence of a stable solid solution with negligible phase transitions in the reversible intercalation region (3.8-4.2 V vs. Li) as well as in the overcharged region. The effect is higher with Mg-doping, irrespective of the Li overstoichiometry. However, the concomitant presence of Mg and Li excess in the structure is important for obtaining small particle sizes. Since Mg-doping induces a quasi metallic behavior in the samples, whereas the Li excess may provide an higher initial capacity, it is suggested that the Li_1.08Mg_0.06CoO₂ composition may be of interest as positive cathode for advanced Li-ion batteries.