Leveraging social semantic components in executable environments for learning

Learning can benefit from the modern Web structure through the convergence of top‐down encyclopedic institutional knowledge and bottom‐up user‐generated annotations. A promising approach to such convergence consists in leveraging the social functionalities in 3.0 executable environments through the recommendation of tags with the mediation of lexical and semantic resources. This paper addresses such issues through the design and evaluation of a tag recommendation system in a Web 3.0 Web portal, ‘150 Digit’. Designed for schools, 150 Digit encourages students and teachers to interact with a set of four exhibitions on the historical and social aspects of the Italian unification process in a virtual environment. The website displays the exhibits and their related documents promoting the users' active participation through tagging, voting and commenting on the exhibits. Tags become a way for students to create and explore new relations among the site contents, orthogonal to the institutional viewpoint. In this paper, we illustrate the recommendation strategy incorporated in 150 Digit, which relies on a semantic middleware to mediate between the input expressed by the users through tags and the top‐down institutional classification provided by the curators of the exhibitions. Following this, we describe the evaluation process conducted in a real experimental setting and discuss the evaluation results and their implications for learning environments.     

A synthetic biology approach to bio-chem-ICT: first moves towards chemical communication between synthetic and natural cells

In this article we present novel aspects of the impact that synthetic biology (SB) can express in a field traditionally based on computer science: information and communication technologies (ICTs), an area that we will consider taking into account also possible implications for artificial intelligence (AI) research. In the first part of this article we will shortly introduce some recent theoretical and experimental issues related to our approach in SB, discussing their relevance and potentiality in the field. Next, we define an original SB research programme that aims at contributing to the development of bio-chem-ICTs and AI based on chemical communication between natural and synthetic cells. In particular we present (i) a mathematical model that allows us to simulate the main features of the system under construction; and (ii) preliminary wet-lab experiments showing the feasibility of our research programme. Based on the bottom-up construction of synthetic cells, the traits of this novel approach and their connections with recent conceptual and technological trends are finally discussed.     

New results on the Gaussian projection filter with small observation noise

In this paper we define a one dimensional Gaussian projection filter (GPF) for a one dimensional diffusion and show that it behaves as nicely as the previously studied two dimensional GPF w.r.t. the true state. We extend part of the results on its nice behaviour to systems with bounded but not necessarily Lipschitz drift, and observe that in this case the resulting efficient filter does not depend on the drift itself.     

Observational Equivalence for the Interaction Combinators and Internal Separation

We define an observational equivalence for Lafont's interaction combinators, which we prove to be the least discriminating non-trivial congruence on total nets (nets admitting a deadlock-free normal form) respecting reduction. More interestingly, this equivalence enjoys an internal separation property similar to that of Böhm's Theorem for the λ-calculus.     

Integration of biocontrol agents and food-grade additives for enhancing protection of stored apples from Penicillium expansum

Forty-nine compounds currently used as additives in foods were tested in combination with three biocontrol agents, the yeasts Rhodotorula glutinis, Cryptococcus laurentii, and the yeastlike fungus Aureobasidium pullulans, to increase their antagonistic activity against Penicillium expansum, the causal agent of blue mold on apples. Twelve additives dramatically improved the antagonistic activity of one or more of the tested biocontrol agents. In a two-way factorial experiment with these selected additives the percentage of P. expansum rots on apples was significantly influenced by the antagonist and the additive as well as by their interaction. The combination of the biocontrol agents and some additives resulted in a significantly higher activity with respect to the single treatments applied separately, producing additive or synergistic effects. Some of the selected additives combined with a low yeast concentration (106 cells per ml) had comparable or higher efficacy than the biocontrol agents applied alone at a 100-fold higher concentration (10(8) cells per ml). Some organic and inorganic calcium salts, natural gums, and some antioxidants displayed the best results. In general, the effect of each additive was specific to the biocontrol isolate used in the experiments. Possible mechanisms involved in the activity of these beneficial additives and their potential application in effective formulations of postharvest biofungicides are discussed.     

The german dfs and tv-sat satellite control centre in usingen

This paper describes the construction of the control centre for the satellites DFS Kopernikus and TVSAT of the German PTT Administration (DBP Telekom), with emphasis on the implemented technical solutions for monitoring and control. The space and ground segments of the two satellite systems are briefly described in relation to the TT&C operations carried out at the control centre.     

Biological consequences of thrombin receptor deficiency in mice

The thrombin receptor (ThrR) is a membrane-bound, G-protein-coupled receptor for the serine protease thrombin. This receptor is expressed in a wide variety of cells and tissues, and elicits a range of physiological responses associated with tissue injury, inflammation, and wound repair. To achieve a better understanding of the physiological role of the ThrR, we have employed homologous recombination to create mice with a disrupted ThrR gene. Following heterozygous (+/-) intercrosses, a total of 351 surviving offspring were genotyped. Only 7% of these offspring were identified as homozygous (-/-) for the disrupted allele, indicating a profound effect on embryonic development. Paradoxically, adult ThrR-/- mice appeared to be normal by anatomical and histological analysis, including their platelet number and function. Similarly, ThrR deficiency had no detectable effect in adult ThrR-/- mice on basal heart rate, arterial blood pressure, vasomotor responses to angiotensin II and acetycholine, and coagulation parameters, even though the ThrR is expressed in many cardiovascular tissue types. In addition, the loss of ThrR function in the peripheral vasculature of adult ThrR-/- mice was confirmed by the absence of various standard hemodynamic effects of the ThrR-activating peptides SFLLRN-NH2 and TFLLRNPNDK-NH2. Our results indicate that ThrR deficiency has a strong impact on fetal development; however. ThrR-/- mice that proceed to full development display surprisingly little change in phenotype compared to the wild-type.     

Interactive atlas with magnetic resonance on CD-ROM for Macintosh

Computer assisted education in radiology has been increasingly used during the past ten years and now complements traditional learning resources. Magnetic Resonance Imaging (MRI) of musculoskeletal anatomy, and particularly of joints, lends itself naturally to learning modules on computer. This paper describes the design, development and use of an interactive computer assisted teaching module of MR joint anatomy on CD-ROM for Macintosh: to date, we have used this atlas for ankle and elbow anatomy. The atlas is divided into three main sections: MR anatomy, traditional anatomy and a quiz. On each MR image, any anatomical detail can be identified clicking on it with the mouse. Buttons allow to visualize cross-reference points and to go directly on the desired image. If the student wants to look at anatomical drawings of the last identified structure, a button retrieves all the cards in the traditional anatomy section containing that structure. Finally, the student can make his own self-assessment, verifying his learning immediately with the exam mode: the software makes a random selection of 10 MR images where an anatomical structure must be indicated: if the answer is wrong, the software gives the right one and shows the misinterpreted structure. Then, the student is given a total score for his performance. The computer assisted teaching modules present some advantages: the images can be viewed in a given sequence (like traditional learning resources) or in any self-paced, customized way; this possibility, together with the friendly interface of Macintosh computers could make learning more active and pleasant.     

G-Protein-Coupled Estrogen Receptor Expression in Rat Uterine Artery Is Increased by Pregnancy and Induces Dilation in a Ca2+ and ERK1/2 Dependent Manner

Increasing levels of estrogens across gestation are partly responsible for the physiological adaptations of the maternal vasculature to pregnancy. The G protein-coupled estrogen receptor (GPER) mediates acute vasorelaxing effects in the uterine vasculature, which may contribute to the regulation of uteroplacental blood flow. The aim of this study was to investigate whether GPER expression and vasorelaxation may occur following pregnancy. Elucidation of the functional signalling involved was also investigated. Radial uterine and third-order mesenteric arteries were isolated from non-pregnant (NP) and pregnant rats (P). GPER mRNA levels were determined and—concentration–response curve to the GPER-specific agonist, G1 (10⁻¹⁰–10⁻⁶ M), was assessed in arteries pre-constricted with phenylephrine. In uterine arteries, GPER mRNA expression was significantly increased and vasorelaxation to G1 was significantly enhanced in P compared with NP rats. Meanwhile, in mesenteric arteries, there was a similar order of magnitude in NP and P rats. Inhibition of L-type calcium channels and extracellular signal-regulated kinases 1/2 significantly reduced vasorelaxation triggered by G1 in uterine arteries. Increased GPER expression and GPER-mediated vasorelaxation are associated with the advancement of gestation in uterine arteries. The modulation of GPER is exclusive to uterine arteries, thus suggesting a physiological contribution of GPER toward the regulation of uteroplacental blood flow during pregnancy.