Epilepsy Surgery in Children

ObjectiveIn the majority of patients with intractable epilepsy, seizures can be well controlled with appropriate medication. However, current estimates indicate that some of patients with epilepsy are refractory to all forms of medical therapy. The surgical treatment of intractable epilepsy in children has  evolved with advances in technical innovations. These medically intractable patients are candidates for surgical treatment in an attempt to achieve better seizure control. The definitive successful outcome of epilepsy surgery is a seizure-free state without significant neurological impairments.In this article, we will outline the essential elements of presurgical evaluation and describe a variety of therapeutic surgical options, and the related indications, techniques, results and complications of each procedure.

Entanglement Entropy for Logarithmic Conformal Field Theory

We study holographic entanglement entropy for certain logarithmic conformal field theories by making use of their gravity descriptions. The corresponding gravity descriptions are provided by higher derivative gravity at critical points where the equations of motion degenerate leading to a log gravity. When the central charge of the dual theory is zero, the entanglement entropy has a new divergent term whose coefficient is given by the new anomaly of the logarithmic conformal field theory.Comment: 16 pages, no figures, V2: Refs. added, typos fixed, V3: Published versio

Holographic Entanglement Entropy for 4D Conformal Gravity

Using the proposal for holographic entanglement entropy in higher derivative gravities, we compute holographic entanglement entropy for the conformal gravity in four dimensions which turns out to be finite. However, if one subtracts the contribution of the four dimensional Gauss-Bonnet term, the corresponding entanglement entropy has a divergent term and indeed restricted to an Einstein solution of the conformal gravity, the resultant entanglement entropy is exactly the same as that in the Einstein gravity. We will also make a comment on the first law of the entanglement thermodynamics for the conformal gravity in four dimensions.Comment: 16 pages, Published Versio

On Complexity for Higher Derivative Gravities

Using "complexity=action" proposal we study complexity growth of certain gravitational theories containing higher derivative terms. These include critical gravity in diverse dimensions. One observes that the complexity growth for neutral black holes saturates the proposed bound when the results are written in terms of physical quantities of the model. We will also study effects of shock wave to the complexity growth where we find that the presence of massive spin-2 mode slows down the rate of growth.Comment: 18 pages, 3 figures, journal versio

Complexity Growth with Lifshitz Scaling and Hyperscaling Violation

Using complexity=action proposal we study the growth rate of holographic complexity for Lifshitz and hyperscaling violating geometries. We will consider both one and two sided black branes in an Einstein-Maxwell-Dilaton gravitational theory. We find that in either case Lloyd's bound is violated and the rate of growth of complexity saturates to a value which is greater than twice the mass of the corresponding black brane. This value reduces to the mass of the black brane in the isotropic case. We show that in two sided black brane the saturation happens from above while for one sided black brane it happens from below.Comment: 17 pages, 4 figures, v2: typos corrected, references added, v3: Minor corrections, New counter terms added that also contribute to the rate of complexity growth. The conclusion is not changed, now 19 pages, v4: matches published versio

Anthropogenic impacts on mosquito populations in North America over the past century.

The recent emergence and spread of vector-borne viruses including Zika, chikungunya and dengue has raised concerns that climate change may cause mosquito vectors of these diseases to expand into more temperate regions. However, the long-term impact of other anthropogenic factors on mosquito abundance and distributions is less studied. Here, we show that anthropogenic chemical use (DDT; dichlorodiphenyltrichloroethane) and increasing urbanization were the strongest drivers of changes in mosquito populations over the last eight decades in areas on both coasts of North America. Mosquito populations have increased as much as tenfold, and mosquito communities have become two- to fourfold richer over the last five decades. These increases are correlated with the decay in residual environmental DDT concentrations and growing human populations, but not with temperature. These results illustrate the far-reaching impacts of multiple anthropogenic disturbances on animal communities and suggest that interactions between land use and chemical use may have unforeseen consequences on ecosystems

Assessment of changes in biochemical parameters associated with kidney function in patients with multiple sclerosis while taking the drug

زمینه و هدف: بیماری مولتیپل اسکلروزیس، یکی از شایع ترین بیماری های مغز و اعصاب محسوب می گردد. هدف از این مطالعه، بررسی تغییرات پارامترهای بیوشیمیایی مرتبط با عملکرد کلیه شامل اوره، اوریک اسید و کراتینین در بیماران مبتلا به ام اس در حین مصرف دارو و مقایسه آن ها با گروه کنترل است. روش بررسی: در این مطالعه، سطح سرمی اوره، اوریک اسید و کراتینین در 52 بیمار مبتلا به ام اس اندازه گیری شد و با 52 فرد سالم که از نظر سنی و جنسی و BMI با گروه بیمار هماهنگ بودند، مقایسه گردید. در نهایت داده ها با استفاده از روش تی تست، شاخص های میانگین و انحراف معیار توسط نرم افزار SPSS تحلیل شدند. یافته ها: میانگین سطح سرمی اوره در گروه بیمار و سالم به ترتیب 58/4±38/14 و 33/4±86/13 میلی گرم بر دسی لیتر مشاهده شد. میانگین غلظت اسید اوریک در گروه بیمار 99/0±66/4 و در گروه سالم 06/1±64/4 میلی گرم بر دسی لیتر و میانگین غلظت کراتینین نیز در گروه بیمار و سالم به ترتیب 10/0±85/0 و 11/0±78/0 میلی گرم بر دسی لیتر به دست آمد. نتیجه گیری: یافته های این تحقیق نشان داد که سطح سرمی اوره، اسید اوریک و کراتینین هیچ تفاوت آماری معنی داری بین گروه بیمار و کنترل نداشت

Deterministic normal contact of rough surfaces with adhesion using a surface integral method

The fundamental problem of adhesion in the presence of surface roughness and its effect on the prediction of friction has been a hot topic for decades in numerous areas of science and engineering, attracting even more attention in recent years in areas such as geotechnics and tectonics, nanotechnology, high-value manufacturing and biomechanics. In this paper a new model for deterministic calculation of the contact mechanics for rough surfaces in the presence of adhesion is presented. The contact solver is an in-house boundary element method that incorporates fast Fourier transform for numerical efficiency. The adhesive contact model considers full Lennard-Jones potentials and surface integration at the asperity level and is validated against models in the literature. Finally, the effect of surface roughness on the adhesion between surfaces was studied, and it was shown that the root mean square gradient of surface roughness can change the adhesive pressures irrespective of the root mean square surface roughness. We have tested two adhesion parameters based on Johnson's modified criteria and Ciavarella's model. We showed that Civarella's model introduces the most reasonable criteria suggesting that the RMS roughness and large wavelength of surfaces roughness are the important parameters of adhesion between rough surfaces

Resolving multi-dimensional plasma phenomena in Hall thrusters using the reduced-order particle-in-cell scheme

Plasma in Hall thrusters exhibits a complex behavior, characterized by the interplay between various dominant processes in each of the thruster’s coordinates. The emergence of high-power Hall thrusters in the recent years and the design modifications intended to extend the lifetime of these devices have further amplified the three-dimensional nature of the plasma behavior. In this regard, the novel reduced-order particle-in-cell (PIC) scheme provides the possibility to resolve the multi-dimensional interactions in a Hall thruster at a computational cost up to two orders of magnitude lower than current multi-dimensional PIC simulations. To demonstrate this point, we present in this article the results from a series of pseudo-two-dimensional simulations we performed in three configurations: axial-azimuthal, azimuthal-radial, and axial-radial. We show that, in each configuration, the pseudo-2D PIC scheme provides a significantly improved picture of the involved physics compared to a one-dimensional PIC simulation and captures self-consistently the coupling between the plasma processes in different directions, notably similar to the observations from full-2D kinetic simulations