A fuzzy logic based-method for prognostic decision making in breast and prostate cancers

Accurate and reliable decision making in oncological prognosis can help in the planning of suitable surgery and therapy, and generally, improve patient management through the different stages of the disease. In recent years, several prognostic markers have been used as indicators of disease progression in oncology. However, the rapid increase in the discovery of novel prognostic markers resulting from the development in medical technology, has dictated the need for developing reliable methods for extracting clinically significant markers where complex and nonlinear interactions between these markers naturally exist. The aim of this paper is to investigate the fuzzy k-nearest neighbor (FK-NN) classifier as a fuzzy logic method that provides a certainty degree for prognostic decision and assessment of the markers, and to compare it with: 1) logistic regression as a statistical method and 2) multilayer feedforward backpropagation neural networks an artificial neural-network tool, the latter two techniques having been widely used for oncological prognosis. In order to achieve this aim, breast and prostate cancer data sets are considered as benchmarks for this analysis. The overall results obtained indicate that the FK-NN-based method yields the highest predictive accuracy, and that it has produced a more reliable prognostic marker model than both the statistical and artificial neural-network-based methods.     

Weighted extended b-splines for one-dimensional electromagnetic problems

This paper considers the weighted extended b-splines as basis function for finite element method in electromagnetics and compares with the standard finite element method applied to the two-point boundary value problems with different boundary conditions. This new approach, which provides more accurate results than standard finite element method, is presented to compare other numerical techniques and applied to one-dimensional electromagnetic problems. Computed results are compared with other numerical results in literature.     

Radially symmetric weighted extended b-spline model

In this paper, the weighted extended basis splines approach in the finite element method is applied to the electrostatic, electromagnetic wave and bioheat problems for inhomogeneous boundary conditions and radially symmetric structures. This new method, which does not need mesh generation, overcomes some of the drawbacks of using meshes and piecewise-uniform or linear trial functions. Two-dimensional radially symmetric electrostatic and electromagnetic wave equations are evaluated. We also attempt to propose a three-dimensional radially symmetric unexposed human eye model for simulating changes in corneal temperature using these new finite elements in conjunction with linear, quadratic and cubic b-splines. Our findings indicate that weighted extended basis spline solutions improve the standard finite element method. The simulation results which are verified using the values reported in the literature, point out to better efficiency in terms of the accuracy level.     

FEM modeling of SAR distribution and temperature increase in human brain from RF exposure

The assessment of radiofrequency exposure level and the exposure setup are critical, because if the exposure levels (related to frequency, power, position, and other variables) are not known, the biological results are not meaningful. In this regard, this study aims to design, implement, and analyze numerical setups for the simulations of radiofrequency exposure related specific absorption rate and temperature increase in the human brain and head. For this purpose, specific models for human head and telephone antenna are chosen, and the FEM is selected for solving PDEs related to electromagnetic wave equations and bioheat equation. After the verification of the methodology chosen by achieving comparable results with the literature, the scope of the study is then turned to the effects of different parameters on the exposure levels. In the end, comprehensive information can be obtained from the simulation results so that risk management policies for electromagnetic radiation can be reevaluated to minimize the possible health hazards. Copyright © 2012 John Wiley & Sons, Ltd.     

Topography based design of the T-DAB SFN for a mountainous area

A method for designing a terrestrial digital audio broadcasting single frequency network (T-DAB SFN) for a mountainous region is proposed. A computer database and the digital terrain elevation data are used in designing the network. Two fundamental approaches are compared; first, utilization of the existing transmitter sites is maximized by applying the initial cost constraint; then, the coverage percent of the service is forced to approach to 100% by applying the coverage efficiency constraint. Finally, a T-DAB SFN hybrid design procedure optimizing both constraints is proposed. The three design approaches are illustrated on the coverage of the mountainous Istanbul-Ankara highway. The results are compared using a reference cost look up table. The hybrid approach is shown to optimize the initial cost and the coverage efficiency, and can be applied to similar networking problems     

Nanoporous Gold Biointerfaces: Modifying Nanostructure to Control Neural Cell Coverage and Enhance Electrophysiological Recording Performance

Nanostructured neural interface coatings have significantly enhanced recording fidelity in both implantable and in vitro devices. As such, nanoporous gold (np‐Au) has shown promise as a multifunctional neural interface coating due, in part, to its ability to promote nanostructure‐mediated reduction in astrocytic surface coverage while not affecting neuronal coverage. The goal of this study is to provide insight into the mechanisms by which the np‐Au nanostructure drives the differential response of neurons versus astrocytes in an in vitro model. Utilizing microfabricated libraries that display varying feature sizes of np‐Au, it is demonstrated that np‐Au influences neural cell coverage through modulating focal adhesion formation in a feature size‐dependent manner. The results here show that surfaces with small (≈30 nm) features control astrocyte spreading through inhibition of focal adhesion formation, while surfaces with large (≈170 nm and greater) features control astrocyte spreading through other mechanotransduction mechanisms. This cellular response combined with lower electrical impedance of np‐Au electrodes significantly enhances the fidelity and stability of electrophysiological recordings from cortical neuron‐glia co‐cultures relative to smooth gold electrodes. Finally, by leveraging the effect of nanostructure on neuronal versus glial cell attachment, the use of laser‐based nanostructure modulation is demonstrated for selectively patterning neurons with micrometer spatial resolution.     

An information-theoretical framework for modeling component-based systems

Software systems tend to be large scale and complex with the inevitable increase in their functionalities. The increasing costs related to system development and maintenance in correlation to the software size requires new assessment tools for the newly evolving development methodologies. Taking advantage of existing tools and methodologies in a mature field is beneficial to relatively young, related disciplines. Therefore, this paper brings modeling techniques from a well-developed and mature discipline, information theory, into component-based software (CBS) engineering. Information-theoretic representation and analysis techniques in general, noiseless information channel concepts in particular, are good candidates to be adopted to model the dynamic behavior of software components and quantify the interaction between them. This modeling approach is realized by first modeling the component integration units of CBS with cubic control flowgraphs. The arcs in these models can be labeled as functions of parameters of their "hidden" components in the originating nodes or arcs, or both. Each of these labeled graphs defines a Shannon language. Then, a set of metrics, labeled as pervasive Shannon metrics is defined. Four case studies are demonstrated to show the applicability of the proposed metrics for assessment of CBS.     

Electromagnetic scattering from a dielectric cylinder of finitelength

The dyadic scattering amplitude is determined for a planar electromagnetic wave incident on a dielectric cylinder of finite length and circular cross section under the assumption that the internal fields induced within the finite-length cylinder can be approximated by those within an infinite-length cylinder. These internal fields are then used to calculate the dyadic scattering amplitude in terms of the cylinder's physical dimensions, orientation, and dielectric properties. The theoretical development is complemented by numerical calculations, and its validity assessed by comparison with experiment     

Effect of molecular conformations on the adsorption behavior of gold-binding peptides

Despite extensive recent reports on combinatorially selected inorganic-binding peptides and their bionanotechnological utility as synthesizers and molecular linkers, there is still only limited knowledge about the molecular mechanisms of peptide binding to solid surfaces. There is, therefore, much work that needs to be carried out in terms of both the fundamentals of solid-binding kinetics of peptides and the effects of peptide primary and secondary structures on their recognition and binding to solid materials. Here we discuss the effects of constraints imposed on FliTrx-selected gold-binding peptide molecular structures upon their quantitative gold-binding affinity. We first selected two novel gold-binding peptide (AuBP) sequences using a FliTrx random peptide display library. These were, then, synthesized in two different forms: cyclic (c), reproducing the original FliTrx gold-binding sequence as displayed on bacterial cells, and linear (l) dodecapeptide gold-binding sequences. All four gold-binding peptides were then analyzed for their adsorption behavior using surface plasmon resonance spectroscopy. The peptides exhibit a range of binding affinities to and adsorption kinetics on gold surfaces, with the equilibrium constant, Keq, varying from 2.5x10(6) to 13.5x10(6) M(-1). Both circular dichroism and molecular mechanics/energy minimization studies reveal that each of the four peptides has various degrees of random coil and polyproline type II molecular conformations in solution. We found that AuBP1 retained its molecular conformation in both the c- and l-forms, and this is reflected in having similar adsorption behavior. On the other hand, the c- and l-forms of AuBP2 have different molecular structures, leading to differences in their gold-binding affinities.