Safety of localizing epilepsy monitoring intracranial electroencephalograph electrodes using MRI: radiofrequency-induced heating

Purpose: To investigate heating during postimplantation localization of intracranial electroencephalograph (EEG) electrodes by MRI. Materials and Methods: A phantom patient with a realistic arrangement of electrodes was used to simulate tissue heating during MRI. Measurements were performed using 1.5 Tesla (T) and 3T MRI scanners, using head- and body-transmit RF-coils. Two electrode-lead configurations were assessed: a standard condition with external electrode-leads physically separated and a fault condition with all lead terminations electrically shorted. Results: Using a head-transmit-receive coil and a 2.4 W/kg head-average specific absorption rate (SAR) sequence, at 1.5T the maximum temperature change remained within safe limits (<1°C). Under standard conditions, we observed greater heating (2.0°C) at 3T on one system and similar heating (<1°C) on a second, compared with the 1.5T system. In all cases these temperature maxima occurred at the grid electrode. In the fault condition, larger temperature increases were observed at both field strengths, particularly for the depth electrodes. Conversely, with a body-transmit coil at 3T significant heating (+6.4°C) was observed (same sequence, 1.2/0.5 W/kg head/body-average) at the grid electrode under standard conditions, substantially exceeding safe limits. These temperature increases neglect perfusion, a major source of heat dissipation in vivo. Conclusion: MRI for intracranial electrode localization can be performed safely at both 1.5T and 3T provided a head-transmit coil is used, electrode leads are separated, and scanner-reported SARs are limited as determined in advance for specific scanner models, RF coils and implant arrangements. Neglecting these restrictions may result in tissue injury

Dietary Patterns and Cognitive Function among Older Community-Dwelling Adults.

Diet may be an important modifiable risk factor for maintenance of cognitive health in later life. This study aimed at examining associations between common dietary indices and dietary patterns defined by factor analysis and cognitive function in older community-dwelling adults. Dietary information for 1499 participants from the Rancho Bernardo Study was collected in 1988⁻1992 and used to calculate the alternate Mediterranean diet score, Alternate Healthy Eating Index (AHEI)-2010 score and factor scores derived from factor analysis of nutrients. Global cognitive function, executive function, verbal fluency and episodic memory were assessed at approximate four-year intervals from 1988⁻2016. Linear mixed models were used to examine associations between dietary patterns and cognitive trajectories. Estimates for the highest vs. lowest tertile in models adjusting for age, sex, education, energy intake, lifestyle variables and retest effect showed greater adherence to the Mediterranean score was associated with better baseline global cognitive function (β (95% CI) = 0.33 (0.11, 0.55)). The AHEI-2010 score was not significantly associated with cognitive performance. Higher loading on a plant polyunsaturated fatty acid (PUFA)/vitamin E factor was associated with better baseline global cognitive function and executive function (β = 0.22 (0.02, 0.42) and β = -7.85 (-13.20, -2.47)). A sugar/low protein factor was associated with poorer baseline cognitive function across multiple domains. Dietary patterns were not associated with cognitive decline over time. Adherence to a healthy diet with foods high in PUFA and vitamin E and a low sugar to protein ratio, as typified by a Mediterranean diet, may be beneficial for cognitive health in late life

The Effects of Roster Turnover on Demand in the National Basketball Association

The purpose of this study was to examine the effects of roster turnover on demand in the National Basketball Association (NBA) over a five-year period (2000–2005) and compare these results to previous research on turnover in Major League Baseball (MLB). A censored regression equation was developed to examine the relationship between roster turnover and season attendance, while controlling for other potentially confounding variables in the model. The censored regression model was used to account for the capacity constraints by forecasting the level of demand beyond capacity using information from the uncensored observations. The regression model was found to be significant with a log-likelihood statistic of 113.631. Previous attendance, current winning percentage, previous winning percentage, number of all-star players, local major sport competition, and team history were found to be significant predictors of attendance. However, the variables measuring the effects of roster turnover were not found to be significant. There were substantial differences in the effect of roster turnover on attendance in the NBA compared with MLB. In addition, these findings provide evidence for using censored regression when dealing with constrained variables. Sellouts in the NBA appear to have an effect on all of the variables in the demand model. Future research will need to be conducted to help sport managers understand the role of roster turnover in specific professional leagues and to better understand the importance of using a censored regression model

Modularity measure of networks with overlapping communities

In this paper we introduce a non-fuzzy measure which has been designed to rank the partitions of a network's nodes into overlapping communities. Such a measure can be useful for both quantifying clusters detected by various methods and during finding the overlapping community-structure by optimization methods. The theoretical problem referring to the separation of overlapping modules is discussed, and an example for possible applications is given as well

The spatio-temporal mapping of epileptic networks: Combination of EEG–fMRI and EEG source imaging

Simultaneous EEG–fMRI acquisitions in patients with epilepsy often reveal distributed patterns of Blood Oxygen Level Dependant (BOLD) change correlated with epileptiform discharges. We investigated if electrical source imaging (ESI) performed on the interictal epileptiform discharges (IED) acquired during fMRI acquisition could be used to study the dynamics of the networks identified by the BOLD effect, thereby avoiding the limitations of combining results from separate recordings. Nine selected patients (13 IED types identified) with focal epilepsy underwent EEG–fMRI. Statistical analysis was performed using SPM5 to create BOLD maps. ESI was performed on the IED recorded during fMRI acquisition using a realistic head model (SMAC) and a distributed linear inverse solution (LAURA). ESI could not be performed in one case. In 10/12 remaining studies, ESI at IED onset (ESIo) was anatomically close to one BOLD cluster. Interestingly, ESIo was closest to the positive BOLD cluster with maximal statistical significance in only 4/12 cases and closest to negative BOLD responses in 4/12 cases. Very small BOLD clusters could also have clinical relevance in some cases. ESI at later time frame (ESIp) showed propagation to remote sources co-localised with other BOLD clusters in half of cases. In concordant cases, the distance between maxima of ESI and the closest EEG–fMRI cluster was less than 33 mm, in agreement with previous studies. We conclude that simultaneous ESI and EEG–fMRI analysis may be able to distinguish areas of BOLD response related to initiation of IED from propagation areas. This combination provides new opportunities for investigating epileptic networks

A Qualitative Exploration of Ticket-Pricing Decisions in Intercollegiate Athletics

Ticket sales represent a significant revenue stream for NCAA Football Bowl Subdivision athletic departments, yet little is known about how administrators determine prices for those tickets. Utilizing strategic planning as the primary framework and supplemented by stakeholder theory, this study examines ticket-pricing decisions from the viewpoint of athletic administrators with various departmental responsibilities to better understand the role of ticket pricing in intercollegiate sport. Twenty athletic administrators, representing two Power 5 and two Group of 5 institutions, were interviewed about their experiences with ticket pricing. In addition to common pricing objectives related to revenue, patronage, and operations, administrators also suggested attendance-oriented pricing objectives unique to college sport pricing theory. However, findings suggest no well-defined organizational objective for ticket pricing exists within the departments sampled. The factors athletic administrators consider when contemplating pricing decisions can be categorized into seven areas: (a) scheduling, (b) research, (c) team performance, (d) stakeholders, (e) discrimination, (f) fan experience, and (g) competitive comparisons

Athletic Ticket Pricing in the Collegiate Environment: An Agenda for Research

As pressure mounts for intercollegiate athletic departments to be more selfsufficient, administrators must respond by increasing generated revenues. Despite the importance of ticket sales in this endeavor, however, little is known about the underlying ticket pricing structures and policies used by National Collegiate Athletic Association (NCAA) institutions. Of the limited existing scholarship focused on managerial pricing decisions in the field of sport management, only professional sports settings have been addressed. Given the unique operational differences between professional and intercollegiate sport, this paper is designed to establish a foundation from which to build future research concerning the pricing of college sport tickets. The frameworks of stakeholder theory and institutional theory are proposed to ground future study in an attempt to strengthen our understanding of the process and behavior of price setting in intercollegiate athletics

Spectral transitions in networks

We study the level spacing distribution p(s) in the spectrum of random networks. According to our numerical results, the shape of p(s) in the Erdos-Renyi (E-R) random graph is determined by the average degree , and p(s) undergoes a dramatic change when is varied around the critical point of the percolation transition, =1. When > 1, the p(s) is described by the statistics of the Gaussian Orthogonal Ensemble (GOE), one of the major statistical ensembles in Random Matrix Theory, whereas at =1 it follows the Poisson level spacing distribution. Closely above the critical point, p(s) can be described in terms of an intermediate distribution between Poisson and the GOE, the Brody-distribution. Furthermore, below the critical point p(s) can be given with the help of the regularised Gamma-function. Motivated by these results, we analyse the behaviour of p(s) in real networks such as the Internet, a word association network and a protein protein interaction network as well. When the giant component of these networks is destroyed in a node deletion process simulating the networks subjected to intentional attack, their level spacing distribution undergoes a similar transition to that of the E-R graph.Comment: 11 pages, 5 figure

Cartoons for e-health informatics

Not only is Hepatitis B serology often misunderstood because of its complex serological implications, but advances in medical science have revolutionised screening and treatment of hepatitis B. To maximise such evolution however, this new information must be relayed effectively and efficiently to current and future medical professionals. Cartoons have been well regarded as a teaching tool in a variety of different settings as is the use of web based technology. Therefore the delivery of a cartoon based learning tool, accessed via on-line learning modules was considered a novel and potentially effective way of disseminating new knowledge. To increase health professionals’ understanding of hepatitis B serology and skill in interpreting the tests that indicate the appropriate treatment, a cartoon series was developed. The cartoons are located on an online educational website and include characters that represent the different antibodies and antigens associated with hepatitis B. The cartoon characters are involved in a series of adventures that represent the various phases of hepatitis B infection, and the paper describes their development. Subsequent research demonstrated that exposure to the online cartoon based learning tool indicates that they are a fun and useful way to increase knowledge