Activation of Elemental Sulfur by Electrogenerated Cyanomethyl Anion: Synthesis of Substituted 2‐Aminothiophenes by the Gewald Reaction

The activation of elemental sulfur (S₈) has been achieved by means of electrogenerated cyanomethyl anion [easily obtained by galvanostatic reduction from acetonitrile/tetraethylammonium hexafluorophosphate (MeCN‐Et₄NPF₆)]. The “activated” sulfur reacted with ylidenemalononitriles to give substituted 2‐aminothiophenes in very high yields. This variation of the Gewald reaction has been carried out using only catalytic amounts of electricity and supporting electrolyte. A proposed mechanism for the interaction between S₈ and cyanomethyl anion is described.     

Statistically assisted routing algorithms (SARA) for hop count based forwarding in wireless sensor networks

The main goal of this paper is to provide routing–table-free online algorithms for wireless sensor networks (WSNs) to select cost (e.g., node residual energies) and delay efficient paths. As basic information to drive the routing process, both node costs and hop count distances are considered. Particular emphasis is given to greedy routing schemes, due to their suitability for resource constrained and highly dynamic networks. For what concerns greedy forwarding, we present the Statistically Assisted Routing Algorithm (SARA), where forwarding decisions are driven by statistical information on the costs of the nodes within coverage and in the second order neighborhood. By analysis, we prove that an optimal online policy exists, we derive its form and we exploit it as the core of SARA. Besides greedy techniques, sub–optimal algorithms where node costs can be partially propagated through the network are also presented. These techniques are based on real time learning LRTA algorithms which, through an initial exploratory phase, converge to quasi globally optimal paths. All the proposed schemes are then compared by simulation against globally optimal solutions, discussing the involved trade–offs and possible performance gains. The results show that the exploitation of second order cost information in SARA substantially increases the goodness of the selected paths with respect to fully localized greedy routing. Finally, the path quality can be further increased by LRTA schemes, whose convergence can be considerably enhanced by properly setting real time search parameters. However, these solutions fail in highly dynamic scenarios as they are unable to adapt the search process to time varying costs. Michele Rossi was born in Ferrara, Italy on October 30th, 1974. He received the Laurea degree in Electrical Engineering (with honors) and the Ph.D. degree in Information Engineering from the University of Ferrara in 2000 and 2004, respectively. Since 2000 he has been a Research Fellow at the Department of Engineering of the University of Ferrara. During 2003 he was on leave at the Center for Wireless Communications (CWC) at the University of California San Diego (UCSD), where he did research on wireless sensor networks. In November 2005 he joined the Department of Information Engineering of the University of Padova, Italy, where he is currently an Assistant Professor. Michele Rossi is currently part of the EU funded Ambient Networks and eSENSE projects. His research interests include: TCP/IP protocols over wireless networks, performance analysis of link layer retransmission techniques, routing and access selection in heterogeneous wireless networks and MAC/routing algorithms for wireless sensor networks. Michele Zorzi was born in Venice, Italy, in 1966. He received the Laurea degree and the Ph.D. degree in Electrical Engineering from the University of Padova, Italy, in 1990 and 1994, respectively. During the Academic Year 1992/93, he was on leave at the University of California, San Diego (UCSD), attending graduate courses and doing research on multiple access in mobile radio networks. In 1993, he joined the faculty of the Dipartimento di Elettronica e Informazione, Politecnico di Milano, Italy. After spending three years with the Center for Wireless Communications at UCSD, in 1998 he joined the School of Engineering of the University of Ferrara, Italy, and in 2003 joined the Department of Information Engineering of the University of Padova, Italy, where he is currently a Professor. His present research interests include performance evaluation in mobile communications systems, random access in mobile radio networks, ad hoc and sensor networks, and energy constrained communications protocols. Dr. Zorzi from 2003 to 2005 was the Editor-In-Chief of the IEEE Wireless Communications Magazine, and currently serves on the Editorial Boards of the IEEE Transactions on Communications, the IEEE Transactions on Wireless Communications, the IEEE Transactions on Mobile Computing, the Wiley Journal of Wireless Communications and Mobile Computing and the ACM/URSI/Kluwer Journal of Wireless Networks. He was also guest editor for special issues in the IEEE Personal Communications Magazine (Energy Management in Personal Communications Systems) and the IEEE Journal on Selected Areas in Communications (Multi-media Network Radios). Ramesh R. Rao was born in Sindri, India, where he completed his undergraduate work at the Regional Engineering College of the University of Madras in Tiruchirapalli, obtaining a BE (Honors) degree in Electronics and Communications in 1980. He completed his graduate work at the University of Maryland, College Park, Maryland where he received his M.S. and Ph.D. Professor Rao is currently a Professor at the University of California, San Diego (UCSD) at the department of Electrical and Computer Engineering in the Irwin and Joan Jacobs School of Engineering, where he has been a member of the faculty since 1984. Professor Rao is the former director of UCSD’s Center for Wireless Communications (CWC), and currently serves as the Qualcomm Endowed Chair in Telecommunications and Information Technologies, and as the Director of the San Diego Division of the California Institute of Telecommunications and Information Technology [Cal-(IT)²]. As Director of the San Diego Division of Cal-(IT)², he leads several interdisciplinary and collaborative projects. His research interests include architectures, protocols and performance analysis of computer and communication networks, and he has published extensively on these topics. Since 1984, Professor Rao has authored over 100 technical papers, contributed book chapters, conducted a number of short courses and delivered invited talks and plenary lectures. He is currently supervising both masters and doctoral students.     

Assessing Crop Water Demand by Remote Sensing and GIS for the Pontina Plain, Central Italy

An estimation of the crop water requirements for the Pontina Plain, Central Italy, was carried out through the use of remote sensing land classification and application of a simple water balance scheme in a GIS environment. The overall crop water demand for the 700 km² area was estimated at about 70 Mm³ year^− 1, i.e. 100 Mm³ year^− 1 irrigation requirements when considering an average irrigation application efficiency of 70%. The simplest and least demanding available methodology, in terms of data and resources, was chosen. The methodology, based on remote sensing and GIS, employed only 4 Landsat ETM+ images and a few meteorological and geographical vectorial layers. The procedure allowed the elaboration of monthly maps of crop evapotranspiration. The application of a spatially distributed simple water balance model, lead to the estimation of temporal and spatial variation of crop water requirements in the study area. This study contributes to fill a gap in the knowledge on agricultural use of water resources in the area, which is essential for the implementation of a sustainable and sound water policy as required in the region for the application of the EU Water Framework Directive.     

On the estimation of mechanical properties of single-walled carbon nanotubes by using a molecular-mechanics based FE approach

Carbon nanotubes (CNTs) have attracted considerable attention in scientific communities due to their remarkable mechanical, thermal and electrical properties (high stiffness, high strength, resilience, etc.). In particular, mechanical properties of single wall nanotubes (SWNTs) have a Young’s modulus of about 1 TPa if normalized to their diameter showing why they are widely considered as reinforcing elements in advanced low weight composite structures. The determinations of mechanical properties of SWNT are currently investigated both experimentally and theoretically. However, to determine CNTs mechanical properties in a direct experimental way is a challenging and not economical task because of the technical difficulties and the costs involved in the manipulation of nanoscale objects. Due to the handling difficulty, estimation of mechanical properties using computer simulations are being performed by several author with different approaches.     

Towards a Formal Semantics for UML/MARTE State Machines Based on Hierarchical Timed Automata

UML is a widely-used,general purpose modeling language.But its lack of a rigorous semantics forbids the thorough analysis of designed solution,and thus precludes the discovery of significant problems at design time.To bridge the gap,the paper investigates the underlying semantics of UML state machine diagrams,along with the time-related modeling elements of MARTE,the profile for modeling and analysis of real-time embedded systems,and proposes a formal operational semantics based on extended hierarchical timed automata.The approach is exemplified on a simple example taken from the automotive domain.Verification is accomplished by translating designed models into the input language of the UPPAAL model checker.     

SnakeSIM: a ROS-based control and simulation framework for perception-driven obstacle-aided locomotion of snake robots

Biological snakes are capable of exploiting roughness in the terrain for locomotion. This feature allows them to adapt to different types of environments. Snake robots that can mimic this behaviour could be fitted with sensors and used for transporting tools to hazardous or confined areas that other robots and humans are unable to access. Snake robot locomotion in a cluttered environment where the snake robot utilises a sensory–perceptual system to perceive the surrounding operational environment for means of propulsion can be defined as perception-driven obstacle-aided locomotion (POAL). The initial testing of new control methods for POAL in a physical environment using a real snake robot imposes challenging requirements on both the robot and the test environment in terms of robustness and predictability. This paper introduces SnakeSIM, a virtual rapid-prototyping framework that allows researchers for the design and simulation of POAL more safely, rapidly and efficiently. SnakeSIM is based on the robot operating system (ROS) and it allows for simulating the snake robot model in a virtual environment cluttered with obstacles. The simulated robot can be equipped with different sensors. Tactile perception can be achieved using contact sensors to retrieve forces, torques, contact positions and contact normals. A depth camera can be attached to the snake robot head for visual perception purposes. Furthermore, SnakeSIM allows for exploiting the large variety of robotics sensors that are supported by ROS. The framework can be transparently integrated with a real robot. To demonstrate the potential of SnakeSIM, a possible control approach for POAL is considered as a case study.     

DNA Binding Mode Analysis of a Core-Extended Naphthalene Diimide as a Conformation-Sensitive Fluorescent Probe of G-Quadruplex Structures

G-quadruplex existence was proved in cells by using both antibodies and small molecule fluorescent probes. However, the G-quadruplex probes designed thus far are structure- but not conformation-specific. Recently, a core-extended naphthalene diimide (c_ex-NDI) was designed and found to provide fluorescent signals of markedly different intensities when bound to G-quadruplexes of different conformations or duplexes. Aiming at evaluating how the fluorescence behaviour of this compound is associated with specific binding modes to the different DNA targets, c_ex-NDI was here studied in its interaction with hybrid G-quadruplex, parallel G-quadruplex, and B-DNA duplex models by biophysical techniques, molecular docking, and biological assays. c_ex-NDI showed different binding modes associated with different amounts of stacking interactions with the three DNA targets. The preferential binding sites were the groove, outer quartet, or intercalative site of the hybrid G-quadruplex, parallel G-quadruplex, and B-DNA duplex, respectively. Interestingly, our data show that the fluorescence intensity of DNA-bound c_ex-NDI correlates with the amount of stacking interactions formed by the ligand with each DNA target, thus providing the rationale behind the conformation-sensitive properties of c_ex-NDI and supporting its use as a fluorescent probe of G-quadruplex structures. Notably, biological assays proved that c_ex-NDI mainly localizes in the G-quadruplex-rich nuclei of cancer cells.     

Gain/phase margin improvement using static generalized sampled-data hold functions

This paper considers the robust control of a finite-dimensional linear time-invariant (FDLTI) continuous-time plant by a static generalized sampled-data hold function (GSHF) controller. It is shown that it is possible to design a static GSHF controller to provide a gain margin as large as desired, and a phase margin of up to 90°. The design is straight-forward, and we illustrate it with an example.     

Identification and characterization of CDS2, a mammalian homolog of the Drosophila CDP-diacylglycerol synthase gene

The technique of intracranial microdialysis was used to investigate the effects of aging on the striatal dopaminergic system of the anesthetized Fischer 344 rat. Microdialysis probes were implanted into the striatum of young (2-8 months) and aged (24-28 months) urethane anesthetized rats. Striatal dialysate levels were analyzed for dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and serotonin (5-HT) by high performance liquid chromatography with electrochemical detection. As compared to the young animals, basal extracellular levels of DA and DOPAC were significantly decreased in two groups of aged animals. Stimulation with excess potassium added through the microdialysis probe produced a robust overflow of DA in the young and aged rat striatum, but the evoked overflow of DA was not diminished in the aged rat striatum as compared to young animals. In contrast, d-amphetamine-evoked overflow of DA was again robust in young and aged animals, but was greatly decreased in the aged rat striatum as compared to the signals recorded in the young rats. Taken together with previous reports, these data support the hypothesis that a major change in the regulation of DA release that occurs in aging involves changes in the function of the neuronal uptake of DA, which may be a compensatory property of DA neurons in senescence.     

Determinants of plasma levels of plasminogen activator inhibitor-1 : A study of normotensive twins

We investigated whether plasma levels of the plasminogen activator inhibitor type 1 antigen (PAI-1:Ag) are genetically determined in monozygotic (MZ) and dizygotic (DZ) twins. Twenty-five pairs of healthy twins underwent measurements of PAI-1:Ag and other variables, including body mass index, mean blood pressure, plasma renin activity, insulin, and glucose. To ascertain the zygosity of twins, highly discriminating micro- and minisatellite systems with variable numbers of tandem repeats were analyzed by PCR amplification followed by polyacrylamide gel electrophoresis. Subjects were also genotyped for the 4G/5G polymorphism by PCR. Estimates of genetic variance and heritability were obtained for PAI-1:Ag, and for body mass index, mean blood pressure, plasma renin activity, glucose, and insulin by jointly examining data in a path analysis with TWINAN90. Results showed that 12 pairs of twins were MZ and 13 were DZ. All tests of genetic variance [within pair (WP): F=6.24, P=0.002; among component (AC): F=2.62, P=0.04; average absolute difference t test=3. 00, P=0.004] showed significant genetic variance of PAI-1:Ag, but not of the other variables. Three tests of heritability (WP=0.837, P=0.002; AC=1.791, P<0.05; intraclass correlation: 1.180, P=0.001) consistently showed significant PAI-1:Ag heritability. Additive genetic influences (A), dominance genetic effect (D), and random environmental influences (E) accounted for 0.714, 0.154, and 0.132 of PAI-1:Ag variance, respectively. No effect of different 4G/5G genotypes was found. Thus, these results show significant genetic variance and heritability of PAI-1:Ag and suggest that A is more important than both D and E in determining PAI-1:Ag variance.