Surgical treatment of drug-resistant focal epilepsy: selection, economic considerations and long-term outcomes

Epilepsy surgery can be an effective treatment for drug-resistant focal epilepsy, but requires careful selection of appropriate candidates to achieve optimal results and minimise the chance of adverse outcomes, including seizure recurrence. Long-term data on multimodal outcomes and a better appreciation of various factors influencing surgical suitability will help facilitate informed discussions between clinicians and prospective surgical candidates. This thesis includes a comprehensive analysis of a cohort of individuals who had epilepsy surgery at a tertiary neurosciences centre over the last 30 years, supplemented by data on individuals who completed presurgical evaluation at the same centre but did not proceed to surgical resection. An inability to localise the epileptogenic zone (EZ), multifocal epilepsy, or an individual choice not to have either intracranial electroencephalography or surgery were the most common reasons why people referred for presurgical evaluation did not proceed to a definitive resection. A predictive model based on demographic, imaging and electroclinical data was constructed to assist early discussions about surgical suitability. Those with normal MRI, extratemporal epilepsy and evidence of bilateral seizure onsets on video telemetry had an estimated 2.9% chance of proceeding to surgery, and people with a normal MRI brain invariably required intracranial EEG. Frontal lobe epilepsy surgery was safe and effective, with a long-term (median seven years) seizure freedom rate of 27%, and another 11% having auras only. Psychiatric comorbidity frequently improved postoperatively and paralleled seizure freedom. Focal MRI abnormality and fewer anti-seizure medications at the time of surgery could help predict a good outcome. In contrast, the site of resection and intracranial monitoring were not independently significant. Localisation of the EZ should rely on clinical features and multimodal investigation, as in our cohort frontal lobe semiology alone could correctly lateralise the EZ in only 77% and localise to a sublobar level in 52%. For those who completed presurgical evaluation but did not have surgery, under 5% had >12 months of seizure-freedom following the decision not to proceed, although a quarter had substantial improvement with further anti-seizure medication (ASM) or neurostimulation. Evaluation for epilepsy surgery was lengthy for individuals and costly for the public health system. Both duration and cost depended on what investigations were required and varied according to different routes through the presurgical pathway, especially the need for intracranial EEG. The median duration of evaluation was 29.7 months (IQR 18.6-44.1 months), with a median cost per person of £9,138 (IQR £6,984-£14,868). Approximately £123,500 was spent per additional person seizure-free

Analyzing the performance of multiple agents with varying bidding behaviors and standard bidders in online auctions

Online auctions have provided an alternative trading method to exchange items without the geographical and time constraints. However, buyers would face difficulties in searching, monitoring, and selecting an auction to participate in. As a consequence, agent technology is introduced to overcome these pitfalls. In this paper, heterogeneous intelligent agents and heterogeneous standard bidders are generated in a simulated auction market and their performances are measured. By doing so, it would further simulate the real online auction marketplace where bidders may have different bidding behaviors or implement different bidder agents. From the simulated results, the average winner's utility, the average number of winning auctions, the average closing price and the average median consumer surplus ratio are used to evaluate the winners' performances. From the results obtained, it is generalized that by using intelligent bidder agents to participate in online auctions, it benefits the bidders. Besides that, market economy is reviewed based on the results obtained

Maximizing bidder’s profit in online auctions using grey system theory predictor agent

Purpose – As the demand for online auctions increases, the process of monitoring multiple auction houses, deciding which auction to participate in and making the right bids, become challenging tasks for consumers. Hence, knowing the closing price of a given auction would be an advantage, since this information will ensure a win in a given auction. However, predicting a closing price for an auction is not easy, since it is dependent on many factors. The purpose of this paper is to report on a predictor agent that utilises grey system theory to predict the closing price for a given auction. Design/methodology/approach – The focus of the research is on grey system agent. This paper reports on the development of a predictor agent that attempts to predict the online auction closing price in order to maximise the bidder's profit. The performance of this predictor agent is compared with two well‐known techniques, the Simple Exponential Function and the Time Series, in a simulated auction environment and in the eBay auction. Findings – The grey theory agent gives a better result when less input data are made, while the Time Series Agent can be used with the availability of a lot of information. Although the Simple Exponential Function Agent is able to predict well with less input data, it is not an appropriate method to be applied in the prediction model since its formula is not realistic and applicable in predicting the online auction closing price. The experimental results also showed that using moving historical data produces a higher accuracy rate than using fixed historical data for all three agents. Originality/value – Grey system theory prediction model, GM(1, 1) has not been applied in online auction prediction. In this paper the authors have applied grey theory into an agent to predict the closing price of an online auction, in order to increase the profit of bidders in the bidding stage. The experimental results show that the accuracy of the grey prediction model is more then 90 per cent, with less then eight historical data inputs

Rotation Group Synchronization via Quotient Manifold

Rotation group $\mathcal{SO}(d)$ synchronization is an important inverse problem and has attracted intense attention from numerous application fields such as graph realization, computer vision, and robotics. In this paper, we focus on the least-squares estimator of rotation group synchronization with general additive noise models, which is a nonconvex optimization problem with manifold constraints. Unlike the phase/orthogonal group synchronization, there are limited provable approaches for solving rotation group synchronization. First, we derive improved estimation results of the least-squares/spectral estimator, illustrating the tightness and validating the existing relaxation methods of solving rotation group synchronization through the optimum of relaxed orthogonal group version under near-optimal noise level for exact recovery. Moreover, departing from the standard approach of utilizing the geometry of the ambient Euclidean space, we adopt an intrinsic Riemannian approach to study orthogonal/rotation group synchronization. Benefiting from a quotient geometric view, we prove the positive definite condition of quotient Riemannian Hessian around the optimum of orthogonal group synchronization problem, and consequently the Riemannian local error bound property is established to analyze the convergence rate properties of various Riemannian algorithms. As a simple and feasible method, the sequential convergence guarantee of the (quotient) Riemannian gradient method for solving orthogonal/rotation group synchronization problem is studied, and we derive its global linear convergence rate to the optimum with the spectral initialization. All results are deterministic without any probabilistic model

Extension of the crRNA enhances Cpf1 gene editing in vitro and in vivo.

Engineering of the Cpf1 crRNA has the potential to enhance its gene editing efficiency and non-viral delivery to cells. Here, we demonstrate that extending the length of its crRNA at the 5 end can enhance the gene editing efficiency of Cpf1 both in cells and in vivo. Extending the 5 end of the crRNA enhances the gene editing efficiency of the Cpf1 RNP to induce non-homologous end-joining and homology-directed repair using electroporation in cells. Additionally, chemical modifications on the extended 5 end of the crRNA result in enhanced serum stability. Also, extending the 5 end of the crRNA by 59 nucleotides increases the delivery efficiency of Cpf1 RNP in cells and in vivo cationic delivery vehicles including polymer nanoparticle. Thus, 5 extension and chemical modification of the Cpf1 crRNA is an effective method for enhancing the gene editing efficiency of Cpf1 and its delivery in vivo

Slice-selective NMR:a non-invasive method for the analysis of separated pyrolysis fuel samples

Pyrolysis oil has been identified as a possible alternative fuel source, however widespread use is hindered by high acidity and water content. These negative characteristics can be mitigated by blending with, for example, biodiesel, marine gas oil and butanol. These blended samples can be unstable and often separate into two distinct phases. NMR spectroscopy is a well-established spectroscopic technique that is finding increasing application in the analysis of pyrolysis oil and blended fuels derived from it. Here, slice-selective NMR, where the NMR spectrum of only a thin slice of the total sample is acquired, is used to study, non-invasively, how the constituent components of blended biofuel samples are partitioned between the two layers. Understanding the outcome of the phase separation is an important step towards understanding why the blended oil samples separate, and may provide answers to mitigating and eventually solving the problem. The NMR method was successfully used to analyse a number of separated biofuel samples - typically separated into an oil layer, containing marine gas oil and biodiesel, above a bio-oil layer with a high water and butanol content

A techno-economic analysis of energy recovery from organic fraction of municipal solid waste (MSW) by an integrated intermediate pyrolysis and combined heat and power (CHP) plant

The increasing environmental concerns and the significant growth of the waste to energy market calls for innovative and flexible technology that can effectively process and convert municipal solid waste into fuels and power at high efficiencies. To ensure the technical and economic feasibility of new technology, a sound understanding of the characteristics of the integrated energy system is essential. In this work, a comprehensive techno-economic analysis of a waste to power and heat plant based on integrated intermediate pyrolysis and CHP (Pyro-CHP) system was performed. The overall plant CHP efficiency was found to be nearly 60% defined as heat and power output compared to feedstock fuel input. By using an established economic evaluation model, the capital investment of a 5 tonne per hour plant was calculated to be £27.64 million and the Levelised Cost of Electricity was £0.063/kWh. This agrees the range of cost given by the UK government. To maximise project viability, technology developers should endeavour to seek ways to reduce the energy production cost. Particular attention should be given to the factors with the greatest influence on the profitability, such as feedstock cost (or gate fee for waste), maintaining plant availability, improving energy productivity and reducing capital cost

The Effect of Bone Quality on Treatment of Intertrochanteric Fractures with Helical Blade Versus Lag Screw Fixation in Cephalomedulary Nails

Introduction. The specific aim of this retrospective study was to determine whether bone quality has any effect on the complication rates or overall survivorship between helical blades and lag screws in cephalomedullary nails used for intertrochanteric hip fractures. Methods. Clinical charts and radiographic studies of patients between Jan 2012 through July 2019 were reviewed. Radiographic images (pre-, intra-, and post-operative) were reviewed to evaluate fracture fixation type, fracture reduction grade, and post-operative complications. DEXA scan results (T-score) and serum alkaline phosphatase (ALP) isoenzyme activity values were collected to evaluate patient bone quality. Results. 303 (helical: 197, screw: 106) cases were included. Complications were found in 31 helical blade cases (16%) and 23 lag screw cases (22%). No statistically significant difference was detected when comparing complication rates to patient bone quality between these two groups. These two groups had similar one-year implant survivorship with respect to T-score, the low ALP level group, and normal ALP level group. The helical blade had higher implant survivorship compared to lag screw in five-year survival rate with respect to osteoporotic group, high ALP level group, and normal ALP level group. (Osteoporotic: 77% vs 69%, High ALP: 73% vs 67%, normal ALP: 70% vs 64%). Conclusions. Similar complication rates were observed between helical blade and lag screw constructs in cephalomedullary femoral nails when accounting for patient bone quality. However, the bone quality had positive influence on the initial post-operative fracture reduction grade, and the five-year implant survivorship