Combinatorial Multicomponent Access to Natural‐Products‐Inspired Peptidomimetics: Discovery of Selective Inhibitors of Microbial Metallo‐aminopeptidases

The development of selective inhibitors of microbial metallo‐aminopeptidases is an important goal in the pursuit of antimicrobials for therapeutic applications. Herein, we disclose a combinatorial approach relying on two Ugi reactions for the generation of peptidomimetics inspired by natural metallo‐aminopeptidase inhibitors. The library was screened for inhibitory activity against the neutral metallo‐aminopeptidase of Escherichia coli (ePepN) and the porcine kidney cortex metallo‐aminopeptidase (pAPN), which was used as a model of the M1‐aminopeptidases of mammals. Six compounds showed typical dose–response inhibition profiles toward recombinant ePepN, with two of them being very potent and highly selective for ePepN over pAPN. Another compound showed moderate ePepN inhibition but total selectivity for this bacterial enzyme over its mammalian orthologue at concentrations of physiological relevance. This strategy proved to be useful for the identification of lead compounds for further optimization and development.     

Constitutive laws for the neutron density current

In this technical note, a fractional wave equation for the average neutron motion in nuclear reactor is considered. This representation covers the full spectrum of the average neutron transport behavior, i.e., Fickian and non-Fickian effects. The fractional diffusion model retains the main dynamic characteristics of the neutron motion in which the relaxation time associated with a rapid variation in the neutron flux contains a fractional exponent that can be manipulated to obtain the best representation of the neutron transport phenomena. The detrended fluctuation analysis (DFA) method is presented in this paper to estimate the fractional exponent.     

Semantic Granularity in Ontology-Driven Geographic Information Systems

The integration of information of different kinds, such as spatial and alphanumeric at different levels of detail, is a challenge. While a solution is not reached, it is widely recognized that the need to integrate information is so pressing that it does not matter if detail is lost, as long as integration is achieved. This paper shows the potential for information retrieval at different levels of granularity inside the framework of information systems based on ontologies. Ontologies are theories that use a specific vocabulary to describe entities, classes, properties and functions related to a certain view of the world. The use of an ontology, translated into an active information system component, leads to ontology-driven information systems and, in the specific case of GIS, leads to what we call ontology-driven geographic information systems.     

Cellulose‐Based Microparticles for Magnetically Controlled Optical Modulation and Sensing

Responsive materials with birefringent optical properties have been exploited for the manipulation of light in several modern electronic devices. While electrical fields are often utilized to achieve optical modulation, magnetic stimuli may offer an enticing complementary approach for controlling and manipulating light remotely. Here, the synthesis and characterization of magnetically responsive birefringent microparticles with unusual magneto‐optical properties are reported. These functional microparticles are prepared via a microfluidic emulsification process, in which water‐based droplets are generated in a flow‐focusing device and stretched into anisotropic shapes before conversion into particles via photopolymerization. Birefringence properties are achieved by aligning cellulose nanocrystals within the microparticles during droplet stretching, whereas magnetic responsiveness results from the addition of superparamagnetic nanoparticles to the initial droplet template. When suspended in a fluid, the microparticles can be controllably manipulated via an external magnetic field to result in unique magneto‐optical coupling effects. Using a remotely actuated magnetic field coupled to a polarized optical microscope, these microparticles can be employed to convert magnetic into optical signals or to estimate the viscosity of the suspending fluid through magnetically driven microrheology.     

LOCALIZING THE IRIS THROUGH MEMETIC ALGORITHMS

An iris recognition system requires efficient image processing techniques in order to duly represent and interpret the iris structural characteristics of an individual. The first processing stage should be the identification of the iris region in an eye image. This work introduces the application of evolutionary algorithms to localize the iris region in an eye image. A method based on memetic algorithms was proposed and used to find the circles that represent the external iris border and the pupil border. This method is applied after detecting the edges of the image through gradient algorithms. The efficiency of the memetic algorithm in solving the problem was compared to the application of the Wildes' method, which uses the Circular Hough Transform (CHT), a well-known algorithm employed to find circles in an edged image. To test the algorithms, images from the UBIRIS database (Proença and Alexandre 2005 Proença , H. and L. A. Alexandre . 2005 . UBIRIS: A noisy iris image database . ICIAP 2005, 13th Int. Conf. on Image Analysis and Processing , Cagliari, Ital. Lect. Notes Comput. Sci. 3617 : 970 – 977 . [Google Scholar]) were used.     

Nonstandard numerical methods for a mathematical model for influenza disease

In this paper we construct and develop two competitive implicit finite difference scheme for a deterministic mathematical model associated with the evolution of influenza A disease in human population. Qualitative dynamics of the model is determined by the basic reproduction number, _R0$R_0$. Numerical schemes developed here are based on nonstandard finite difference methods. Our aim is to transfer essential properties of the continuous model to the discrete schemes and to obtain unconditional stable schemes. The proposed numerical schemes have two fixed points which are identical to the critical points of the continuous model and it is shown that they have the same stability properties. Numerical simulations with different initial conditions, parameters values and time step sizes are developed for different values of parameter _R0$R_0$, convergence to the disease free equilibrium point when _R0<1$R_0<1$ and to the endemic equilibrium point when _R0>1$R_0>1$ are obtained independent of the time step size. These numerical integration schemes are useful since can reproduce the dynamics of original differential equations.     

Use of chromium oxide in digestibility studies: variations of the results as a function of the measurement method

The objective of the present study was to evaluate the agreement of two methods for the determination of chromium oxide in feed, duodenal contents and faeces in the investigation of feed digestibility. Four Holstein steers fitted with permanent ruminal and duodenal cannulae were used in a 4×4 Latin square design experiment. Steers were fed diets varying in urea content three times daily, restricted at a level equivalent to 2·5% of live body weight (dry matter basis). Faecal and duodenal fluxes of dry matter and nitrogen were estimated using chromium oxide (Cr₂O₃) as a indigestible marker. The equivalent Cr₂O₃ concentration in the solution resulting from acid digestion of the samples was measured by chromium determination by simple photometry at 350 nm and by flame atomic absorption spectrometry. Chromium concentrations in feed, duodenal contents and faeces and ruminal and total digestibilities of dry matter and nitrogen were affected by the chromium determination methods used. Despite the fact that the AAS method is more precise and sensible, sometimes its utilisation is limited by availability of equipment. In this situation, the chromium determination by photometric method can be a feasible alternative, since proper corrections in optical density readings are done. © 1998 SCI.     

IDSSs opportunities and problems: Steps to development of an IDSS

IDSSs should contribute to the enhancement of human performance, but their effectiveness can be guaranteed only in the case of certain decision types. The issues explored in this paper show that they can help to overcome some human limitations, especially in complex data and information processes, in uncertainty management, and in coherent reasoning. Integrating human and machine expertise is clearly beneficial, nevertheless with the aim of building intelligent solutions we should not ignore the role of human factors and the problems deriving from the integration of knowledge of multiple experts. The risk is that the systems will become clumsy and vulnerable to embarrassing failures. The paper explores the opportunities for exploitation of IDSSs to provide intelligent advice, intelligent analysis and intelligent evaluation. Some suggestions for research have been proposed looking at the ideas put forward in a recent research project dealing with the development of a system supporting local government authorities on environmental impact assessment procedure.     

Supporting factoring transactions in Brazil using reasoning maps: a language-based DSS for evaluating accounts receivable

Factoring companies are a widespread way of providing working capital to small enterprises in Brazil. This type of financial transaction has higher risks when performed in developing countries, due to unreliable financial information on firms, an unstable environment, and particular managerial practices. This paper describes a case study in which a language-based DSS was developed for a Brazilian factoring company to evaluate the perceived risk of buying accounts receivable; and discusses the suitability of different approaches to decision support for this type of decision in Brazil—which may be relevant for similar situations in other developing countries.     

Validation of the 3D code SARUMAN in a stability and quench experiment with the superconducting magnet SAFFO

Experiments on stability and quench propagation were performed on a NbTi hollow conductor test module allowing heat conduction only between adjacent layers, while the turns in a layer are thermally insulated (2-D winding). The measurements performed over a wide range of operating conditions were used as the experimental data-base for the comparison with the results of the simulations done using the quench analysis code SARUMAN. In the paper the experimental results are compared with the predictions of a 2-D version of SARUMAN, which show that the simulation is able to reproduce the general features of the quench propagation experiments.