INTERNATIONAL TERRORISM: A STUDY IN FORMS AND EFFEETS

Terrorism is known as one of the most dangerous phenomena that has the negatively influence the reality of ‎human societies. Despite human history has never been free from acts of terrorism in all its forms, modern ‎terrorism has exceeded in its magnitude, image and impact all that has been found since human existence. In ‎addition, this phenomenon becomes a matter of concern to human beings wherever it may be exist. ‎Nevertheless, politicians, sociologists, lawmakers and philosophers, as well as various intellectuals and writers ‎alike, accept without hesitation the recognition of the difficulties of identifying and placing terrorism within a ‎comprehensive background that is acceptable to all. The disagreement and the lack of understanding that ‎accompanied and kept pace with all the attempts that were made and are taking place discuss the term of ‎terrorism. The problem of the terrorism under study revolves primarily around a phenomenon that is now ‎plaguing the entire world. This paper discusses a diagnosis of incurable disease called international terrorism to ‎reveal some of the uncertainties and uncertainties in this phenomenon. The importance of the topic is about ‎highlighting the important and effective role played by the international community and the Islamic societies ‎in the fight against terrorism. Furthermore, this paper aims to clarify the concept of international terrorism and ‎and identify the most important forms and dangers resulting from it, which has been increasing rapidly in ‎recent times and the consequent threat to the integrated human security system, whether moral security, ‎economic security, social security, or Political security or environmental security‎.‎

A more accurate account of the effect of k-space sampling and signal decay on the effective spatial resolution in functional MRI

The effects of k-space sampling and signal decay on the effective spatial resolution of MRI and functional MRI (fMRI) are commonly assessed by means of the magnitude point-spread function (PSF), defined as the absolute values (magnitudes) of the complex MR imaging PSF. It is commonly assumed that this magnitude PSF signifies blurring, which can be quantified by its full-width at half-maximum (FWHM). Here we show that the magnitude PSF fails to accurately represent the true effects of k-space sampling and signal decay.Firstly, a substantial part of the width of the magnitude PSF is due to MRI sampling per se. This part is independent of any signal decay and its effect depends on the spatial frequency composition of the imaged object. Therefore, it cannot always be expected to introduce blurring. Secondly, MRI reconstruction is typically followed by taking the absolute values (magnitude image) of the reconstructed complex image. This introduces a non-linear stage into the process of image formation. The complex imaging PSF does not fully describe this process, since it does not reflect the stage of taking the magnitude image. Its corresponding magnitude PSF fails to correctly describe this process, since convolving the original pattern with the magnitude PSF is different from the true process of taking the absolute following a convolution with the complex imaging PSF. Lastly, signal decay can have not only a blurring, but also a high-pass filtering effect. This cannot be reflected by the strictly positive width of the magnitude PSF.As an alternative, we propose to first approximate the MRI process linearly. We then model the linear approximation by decomposing it into a signal decay-independent MR sampling part and an approximation of the signal decay effect. We approximate the latter as a convolution with a Gaussian PSF or, if the effect is that of high-pass filtering, as reversing the effect of a convolution with a Gaussian PSF. We show that for typical high-resolution fMRI at 7 Tesla, signal decay in Spin-Echo has a moderate blurring effect (FWHM = 0.89 voxels, corresponds to 0.44 mm for 0.5 mm wide voxels). In contrast, Gradient-Echo acts as a moderate high-pass filter that can be interpreted as reversing a Gaussian blurring with FWHM = 0.59 voxels (0.30 mm for 0.5 mm wide voxels). Our improved approximations and findings hold not only for Gradient-Echo and Spin-Echo fMRI but also for GRASE and VASO fMRI. Our findings support the correct planning, interpretation, and modeling of high-resolution fMRI.

Application of Genetic Algorithm in Denoising MRI Images Clouded with Rician Noise

In this research Genetic Algorithm (GA) is suggested for remotion of Rician Noise. This type of disturbance primarily occurs in low signal to noise (SNR) regions. Original low signal is clouded due to presence of Rician noise and measurement gets hindered in low SNR areas. To defeat the trouble real and imaginary data in the image field are rectified, before construction of the magnitude image. The noise diminution filtering (or denoising) is attained by Genetic Algorithm. New genetic manipulator is used that blends crossover and adaptive mutation to improve the convergence rate and solution quality of GA. For validating the results, the proposed filter was tested successfully by keeping the number of generations fixed and gradually increasing the noise level. Similar trends of decrease were obtained in the mean square error values after the filtering was performed. This new proficiency efficaciously reduces the standard deviation and significantly lowers the rectified noise after the filtering was performed.

Abstract WP292: Quantitative Susceptibility Mapping for Reliably Measuring Hematoma Volume in Magnetic Resonance Imaging

Introduction T2* weighted gradient echo MRI has been increasingly recognized as a sensitive tool in detecting intracerebral hemorrhage. However, its blooming artifacts is highly dependent on imaging parameters including TE, field strength and voxel size, making it difficult to reliably estimate the hematoma volume, a key predictor of morbidity and mortality of hemorrhage. Recently, a novel quantitative susceptibility mapping (QSM) technology has been developed for processing gradient echo MRI data to map tissue susceptibility property without blooming artifacts and dependence on imaging parameters. Hypothesis We assessed the hypothesis that hematoma volume measurement on QSM is independent of imaging parameters, eliminating its TE dependence on gradient echo MRI. Method A retrospective image analysis of MRI was approved by our IRB with HIPPA compliance. We randomly selected 16 patients who underwent intracerebral hemorrhage MRI including a 3D multiecho T2*w sequence: 8-11 echoes with first echo TE/ echo spacing/ TR= 5/5/50 msec. Postprocessed images of gradient echo MRI included susceptibility weighted imaging (SWI), R2* (quantitative 1/T2* mapping), and QSM at various TEs. Hematoma volumes were measured from all these images. Results Linear regression of hematoma volume vs TE over all subjects showed substantial slopes for gradient echo magnitude (0.45±0.31 L/s), SWI (0.52±0.46) and R2* (0.39±0.30) but nearly zero slope for QSM (0.01±0.05). At TE=20 msec, hematoma volume on QSM was 0.80x that on gradient echo magnitude image (R2=0.99), and hematoma volume on CT is also 0.8x that on gradient echo magnitude image according to literature (Stroke 2008;39:2017-2020). Conclusion In conclusion, quantitative susceptibility mapping can provide reliable measurement of hematoma volume, independent echo time and similar to CT.