Investigation, design, and integration of insert gradient coils in magnetic resonance imaging

Diffusion-weighted magnetic resonance imaging utilizes the magnetic gradients of the system to de-phase protons undergoing diffusion with respect to the overall mag­ netization. Areas of the image with reduced signal when compared to an un-weighted image represent where protons have undergone diffusion. The stronger the gradient applied during diffusion-weighting, the larger the signal loss due to diffusion, and the larger the b-value differentiating the diffusion coefficients. However, the maximum gradient strength during image acquisition is limited by both the original strength of the signal and peripheral nerve stimulation. Nerve stimulation is induced because the changing magnetic fields of the gradient pulse sequence induce electric fields that cause stimulation. The stimulation thresh­ old can be measured either in terms of the pulse sequence parameters of maximum gradient strength and slew rate, or in terms of the induced electric field and the duration of the electric field pulse. A finite-difference simulation was used to approximate the electric field induced inside a visible man model. The effect of varying the size, resolution, and position of the model inside the simulation was investigated with the wire pattern from a customized head/neck gradient coil. For accurate simulations, it was most important to ensure that the resolution of the model was sufficient to capture the air cavities of the sinus and trachea. m The peripheral nerve stimulation thresholds of a planar gradient coil were deter­ mined from human experiments. While the electrical stimulation threshold parame­ ters did not vary significantly from previous studies, the minimum gradient change and slew rate required to cause stimulation were significantly higher for the planar gradient than for reported thresholds of cylindrically designed gradient systems. Several non-cylindrical localized gradient designs were investigated for diffusion- weighted contrast as a fourth gradient, in addition to the three imaging axes. Both resistive and inductive merits were investigated. Of these, inductive values proved to be the limiting factor when designing coils sized to perform in a full body MRI system. Optimal merit and gradient strength were obtained from a butterfly design, and planar coils provided localized strength over a larger region. A butterfly coil was constructed with hollow copper wiring and powered to produce diffusion weighting during MRI. Diffusion contrast b—1300 s/mm2was obtained using the insert with significant time and signal to noise ratio improvement

African American Male Achievement Initiative: A Deeper Look At African American Males In OUSD

This report provides further insights into the status of African American boys in Oakland Unified School Distric (OUSD) and aims to reverse the academic and social inequities they face in seven key areas: the achievement gap, graduation rates, literacy, suspensions, attendance, middle school holding power, and juvenile detention. A framework of three levels of well-being (on course, at risk of falling off course, and off course) was used to understand how African American male students are faring in these areas

African American Male Achievement Initiative: A Closer Look At Attendance Of African American Males In OUSD

This report examines data, best practices, and policies related to attendance and chronic absence and offers recommendations for reducing the levels of chromic absence for African American males in Oakland Unified School District (OUSD). It analyzes one year of attendance data (2010-2011) for African American males in OUSD, looking at chronic absence by grade level, types of absence, and reasons given for absence, as well as comparing rates of chronic absence to other males groups in OUSD

African American Male Achievement Initiative: A Closer Look At Suspensions Of African American Males In OUSD

This report examines the data, literature, and policy around suspensions of African American male students to uncover and better understand the disparities between this group and all other ethnic and gender groups. This report analyzes one year of suspension data from the Oakland Unified School District (OUSD, 2010-11), looking at suspensions by demographics, grade level, school level, and types of offenses

Mothers Who Kill: Number of Victims, Sexism, and a Just World

High profile cases, such as those of Susan Smith and Andrea Yates, have drawn the attention of the public and scholars to the act of filicide, the killing of a child by his/her parent. Although relatively rare, filicide has occurred throughout history. Most experts agree mental illness is frequently an underlying factor when mothers kill their children. After giving birth women are at greater risk for psychiatric illness, specifically postpartum depression. Symptoms of postpartum depression include abrupt mood swings, suicidal thoughts, and thinking about hurting their new born child (Davidson, 2000). Postpartum depression occurs in only one woman out of 200 and full-blown postpartum psychosis develops in only .2% of these women. Infanticide, the killing of a child less than one year of age, is frequently occasioned by postpartum psychosis (Meyer & Oberman, 2001).Society perceives mothers who kill their children as unique cases different from other people accused of crimes. “Mothers who murder their children evoke sympathy, confusion, and abhorrence…Society is torn between wanting to protect the helpless child and recognizing that perhaps the very act of child murder suggests that the mother was severely ill or demented and therefore deserving of sympathetic sentencing (Manchester, 2003, p. 714).

Development and Validation of a Questionnaire for Analyzing Real-Life Falls in Long-Term Care Captured On Video

Background Falls are the number one cause of injuries in older adults, and are particularly common in long-term care (LTC). Lack of objective evidence on the mechanisms of falls in this setting is a major barrier to prevention. Video capture of real-life falls can help to address this barrier, if valid tools are available for data analysis. To address this need, we developed a 24-item fall video analysis questionnaire (FVAQ) to probe key biomechanical, behavioural, situational, and environmental aspects of the initiation, descent, and impact stages of falls. We then tested the reliability of this tool using video footage of falls collected in LTC. Methods Over three years, we video-captured 221 falls experienced by 130 individuals in common areas (e.g., dining rooms, hallways, and lounges) of two LTC facilities. The FVAQ was developed through literature review and an iterative process to ensure our responses captured the most common behaviours observed in preliminary review of fall videos. Inter-rater reliability was assessed by comparing responses from two teams, each having three members, who reviewed 15 randomly-selected videos. Intra-rater reliability was measured by comparing responses from one team at baseline and 12 months later. Results In 17 of the 24 questions, the percentage of inter- and intra-rater agreement was over 80% and the Cohen\u27s Kappa was greater than 0.60, reflecting good reliability. These included questions on the cause of imbalance, activity at the time of the fall, fall direction, stepping responses, and impact to specific body sites. Poorer agreement was observed for footwear, contribution of clutter, reach-to-grasp responses, and perceived site of injury risk. Conclusions Our results provide strong evidence of the reliability of the FVAQ for classifying biomechanical, behavioural, situational, and environmental aspects of falls captured on video in common areas in LTC. Application of this tool should reveal new and important strategies for the prevention and treatment of falls and fall-related injuries in this setting

To Fib or Not to Fib: Misdiagnosis of Atrial Fibrillation on Telemetry Case Presentation and Root Cause Analysis

Case presentation, current practices of telemetry management, root cause analysis, goals for improvement, proposed intervention and next steps

Do Exergames Allow Children To Achieve Physical Activity Intensity Commensurate With National Guidelines?

The purpose of this study was to determine if two popular exergames, Wii Fit™ and EA Sports Active™, both games for the Nintendo Wii™ console, help children achieve intensity consistent with recommended physical activity guidelines. Thirty children (19 males and 11 females, Mean age = 9.4 ± 1.8 years) participated in this study by playing each game during one research session. During the session participants wore a heart rate monitor and accelerometer to measure exercise intensity. Perceived exertion (RPE) was measured with the children’s run/walk OMNI scale. All three measures of exercise intensity (heart rate, accelerometer counts, and RPE) found that the EA Sports Active™ game session elicited higher exercise intensity. However, heart rate data found both games to achieve moderate intensity (65-68% age-predicted HRmax). When using heart rate as an indicator of exercise intensity it appears that both exergames were of sufficient intensity to achieve physical activity guidelines. Future studies should continue to investigate the utility of exergaming in helping children to become more physically active