A seed specific dose kernel method for low-energy brachytherapy dosimetry.

We describe a method for independently verifying the dose distributions from pre- and post-implant brachytherapy source distributions. Monte Carlo calculations have been performed to characterize the three-dimensional dose distribution in water phantom from a low-energy brachytherapy source. The calculations are performed in a voxelized, Cartesian coordinate geometry and normalized based upon a separate Monte Carlo calculation for the seed specific air-kerma strength to produce an absolute dose grid with units of cGy hr(-1) x U(-1). The seed-specific, three-dimensional dose grid is stored as a text file for processing using a separate visual basic program. This program requires the coordinate positions of each seed in the pre- or post-plan and sums the kernel file for a three-dimensional composite dose distribution. A kernel matrix size of 81x81x81 with a voxel size of 1.0x1.0x1.0 mm3 was chosen as a compromise between calculation time, kernel size, and truncation of the stored dose distribution as a function of radial distance from the midpoint of the seed. Good agreement is achieved for a representative pre- and post-plan comparison versus a commercial implementation of the TG-43 brachytherapy dosimetry protocol

Moving multi-directional harnessed balance training from the clinic to the community: harnesses in a community garden

Individuals such as the elderly and disabled frequently have trouble balancing, and therefore have a higher fall risk. A fear of falling can significantly impact mobility, thereby limiting participation in life activities. Balance training programs are often ineffective, because they are not intense enough or related to real life. Our lab has developed a clinic-based intense, engaging multi-directional harnessed balance training program that addresses these concerns. This work describes the process of transitioning the clinic-based training program into a community setting, specifically community gardening. We developed a harness system for a community garden high tunnel with raised beds. We incorporated inexpensive active assist mechanisms to assist standing up. We also equipped the harness system with a wearable sensor system including pressure sensors, a heart rate monitor, and a position motion tracking system. We developed analysis software for the system allowing us to quantify changes in balance. As compared to a non-harnessed environment where falls are possible, we hypothesize that the harness will provide the confidence to practice and thereby develop skill with more challenging balance activities in a real- life environment. We also hypothesize that the active assist mechanism will provide leg strengthening opportunities, further improving balance.https://engagedscholarship.csuohio.edu/u_poster_2017/1024/thumbnail.jp

The Relationship Between Observed and Perceived Measures of Balance Stability

Introduction Injurious falls have risen significantly in the past decade, raising concerns about the efficacy of fall prevention programs. The purpose of this study was to analyze the correlation between perceived and observed balance measures used in a falls prevention program. Methods Subjects (S) were 70 (F), 59 (F), and 73(M). They were taught the Rate of Perceived Stability (RPS), a perceived measure of balance intensity and completed the Berg Balance Test (Berg), Timed up and Go (TUG), and Activities Specific Balance Confidence Scale (ABC). The Berg and TUG are observed measures and the ABC is a perceived measure. Last, subjects underwent Limits of Stability Testing (LOS), an observed measure allowing calculation of base of support (BOS) and center of mass (COM). Results The Berg predicted fall risk for S2 and 3 (2:51/56, 3:43/56). TUG results were well below age norms for S 1 and 3 (1: 12.1s, 3: 12.7s). S1 and 3 reported fear of falling; S 2 and 3 reported frequent falls. LOS testing showed S1 and 3 with minimal COM movement. Discussion S1, with a fear of falling, history of falls, and no fall risk, moved slowly and with minimal COM displacement. S2, with a fall risk and history of falls, moved with more COM excursion. S3, with a fall risk and history of falls, moved slowly with little COM excursion. Perceived versus observed clinical balance measures correlated well. LOS analysis was more complex, however, perceived RPS scores mirrored observed measures. This study provides initial feasibility data on this assessment protocol. Conclusion Perceived balance scores matched actual balance measures when overall excursion and movement speed were taken into account in this preliminary descriptive study.https://engagedscholarship.csuohio.edu/u_poster_2016/1018/thumbnail.jp

Simple, low-cost solar pumping is now a reality

A breakthrough has been achieved in making small solar pumps affordable and easy to set up and use by small farmers in Africa. Numerous off-the-shelf pumps running on direct current were tested when connected directly to a single solar panel, without any battery or additional electronics. Of the many pump models tested, two were found to meet our criteria for low-cost solar pumping for small-scale irrigation. These pumps have been successfully operating in Cameroon, Chad, Burkina Faso, Senegal and Canada since 2014. We present information on the components, cost and performance of these pumps for small-scale irrigation

The Relationship Between Observed and Perceived Measures of Balance Stability

Introduction Injurious falls have risen significantly in the past decade, raising concerns about the efficacy of fall prevention programs. The purpose of this study was to analyze the correlation between perceived and observed balance measures used in a falls prevention program. Methods Subjects (S) were 70 (F), 59 (F), and 73(M). They were taught the Rate of Perceived Stability (RPS), a perceived measure of balance intensity and completed the Berg Balance Test (Berg), Timed up and Go (TUG), and Activities Specific Balance Confidence Scale (ABC). The Berg and TUG are observed measures and the ABC is a perceived measure. Last, subjects underwent Limits of Stability Testing (LOS), an observed measure allowing calculation of base of support (BOS) and center of mass (COM). Results The Berg predicted fall risk for S2 and 3 (2:51/56, 3:43/56). TUG results were well below age norms for S 1 and 3 (1: 12.1s, 3: 12.7s). S1 and 3 reported fear of falling; S 2 and 3 reported frequent falls. LOS testing showed S1 and 3 with minimal COM movement. Discussion S1, with a fear of falling, history of falls, and no fall risk, moved slowly and with minimal COM displacement. S2, with a fall risk and history of falls, moved with more COM excursion. S3, with a fall risk and history of falls, moved slowly with little COM excursion. Perceived versus observed clinical balance measures correlated well. LOS analysis was more complex, however, perceived RPS scores mirrored observed measures. This study provides initial feasibility data on this assessment protocol. Conclusion Perceived balance scores matched actual balance measures when overall excursion and movement speed were taken into account in this preliminary descriptive study.https://engagedscholarship.csuohio.edu/u_poster_2016/1018/thumbnail.jp

Time-course of effects of external beam radiation on [18F]FDG uptake in healthy tissue and bone marrow.

The utility of PET for monitoring responses to radiation therapy have been complicated by metabolically active processes in surrounding normal tissues. We examined the time-course of [18F]FDG uptake in normal tissues using small animal-dedicated PET during the 2 month period following external beam radiation. Four mice received 12 Gy of external beam radiation, in a single fraction to the left half of the body. Small animal [18F]FDG-PET scans were acquired for each mouse at 0 (pre-radiation), 1, 2, 3, 4, 5, 8, 12, 19, 24, and 38 days following irradiation. [18F]FDG activity in various tissues was compared between irradiated and non-irradiated body halves before, and at each time point after irradiation. Radiation had a significant impact on [18F]FDG uptake in previously healthy tissues, and time-course of effects differed in different types of tissues. For example, liver tissue demonstrated increased uptake, particularly over days 3-12, with the mean left to right uptake ratio increasing 52% over mean baseline values (p < 0.0001). In contrast, femoral bone marrow uptake demonstrated decreased uptake, particularly over days 2-8, with the mean left to right uptake ratio decreasing 26% below mean baseline values (p = 0.0005). Significant effects were also seen in lung and brain tissue. Radiation had diverse effects on [18F]FDG uptake in previously healthy tissues. These kinds of data may help lay groundwork for a systematically acquired database of the time-course of effects of radiation on healthy tissues, useful for animal models of cancer therapy imminently, as well as interspecies extrapolations pertinent to clinical application eventually

A Monte Carlo based phase space model for quality assurance of intensity modulated radiotherapy incorporating leaf specific characteristics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134797/1/mp3409.pd

Cooper Pairing in Ultracold K-40 Using Feshbach Resonances

We point out that the fermionic isotope K-40 is a likely candidate for the formation of Cooper pairs in an ultracold atomic gas. Specifically, in an optical trap that simultaneously traps the spin states |9/2,-9/2> and |9/2,-7/2>, there exists a broad magnetic field Feshbach resonance at B = 196 gauss that can provide the required strong attractive interaction between atoms. An additional resonance, at B = 191 gauss, could generate p-wave pairing between identical |9/2,-7/2> atoms. A Cooper-paired degenerate Fermi gas could thus be constructed with existing ultracold atom technology.Comment: 4 pages, 2 figs, submitted to Phys. Rev.

Resonance superfluidity in a quantum degenerate Fermi gas

We consider the superfluid phase transition that arises when a Feshbach resonance pairing occurs in a dilute Fermi gas. We apply our theory to consider a specific resonance in potassium-40, and find that for achievable experimental conditions, the transition to a superfluid phase is possible at the high critical temperature of about 0.5 T_F. Observation of superfluidity in this regime would provide the opportunity to experimentally study the crossover from the superfluid phase of weakly-coupled fermions to the Bose-Einstein condensation of strongly-bound composite bosons.Comment: 4 pages, 3 figure