Suicide Promotion Online: Frequency of Access by High Risk Individuals

Online suicide promotion is a recent and potentially problematic phenomenon in which individuals provide detailed instructions for or encouragement to enact self-harm to other internet users. These types of resources are freely available to anyone willing to look for them, and there is no legal hindrance to prevent their continued operations. The purpose of this study was to investigate the frequency with which people in the general, nonclinical population access these sites with a particular interested in individuals experiencing depressive symptoms and in young adults. Both populations are likely to be influenced by suicide promotion. I predicted that individuals with depression would access suicide promotion and prevention material online more frequently than others and that young people, regardless of depressive symptoms, would access suicide-promotion material more frequently than older individuals. Participants, responding to an online ad, answered a series of surveys over the internet. A total of 127 people completed the study. Approximately 40% of respondents indicated that they had, at some point, viewed suicide-promotion material online while 22% indicated that they do so frequently. Approximately 56% reported accessing suicide prevention sites as well. Results revealed a strong association between depressive symptoms and the frequency of accessing suicide-promotion material. A strong association also exists between the frequency of depressive symptoms and the frequency of accessing suicide-prevention material. People experiencing depression appear to be turning to the internet for information on suicide, and they are reading information from a variety of potential influences. There was no relationship between age and frequency of access, indicating that older individuals are just as likely to view suicide-promotion materials as younger individuals

Participatory design--the next step

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1994.Includes bibliographical references (leaves 202-210).by Barbara D. Stabin.M.C.P

VIDA: A Voxel-Based Dosimetry Method for Targeted Radionuclide Therapy Using Geant4

We have developed the Voxel-Based Internal Dosimetry Application (VIDA) to provide patient-specific dosimetry in targeted radionuclide therapy performing Monte Carlo simulations of radiation transport with the Geant4 toolkit. The code generates voxel-level dose rate maps using anatomical and physiological data taken from individual patients. Voxel level dose rate curves are then fit and integrated to yield a spatial map of radiation absorbed dose. In this article, we present validation studies using established dosimetry results, including self-dose factors (DFs) from the OLINDA/EXM program for uniform activity in unit density spheres and organ self- and cross-organ DFs in the Radiation Dose Assessment Resource (RADAR) reference adult phantom. The comparison with reference data demonstrated agreement within 5% for self-DFs to spheres and reference phantom source organs for four common radionuclides used in targeted therapy (131I, 90Y, 111In, 177Lu). Agreement within 9% was achieved for cross-organ DFs. We also present dose estimates to normal tissues and tumors from studies of two non-Hodgkin Lymphoma patients treated by 131I radioimmunotherapy, with comparison to results generated independently with another dosimetry code. A relative difference of 12% or less was found between methods for mean absorbed tumor doses accounting for tumor regression.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140327/1/cbr.2014.1713.pd

Comparison of I-131 Radioimmunotherapy Tumor Dosimetry: Unit Density Sphere Model Versus Patient-Specific Monte Carlo Calculations

High computational requirements restrict the use of Monte Carlo algorithms for dose estimation in a clinical setting, despite the fact that they are considered more accurate than traditional methods. The goal of this study was to compare mean tumor absorbed dose estimates using the unit density sphere model incorporated in OLINDA with previously reported dose estimates from Monte Carlo simulations using the dose planning method (DPMMC) particle transport algorithm. The dataset (57 tumors, 19 lymphoma patients who underwent SPECT/CT imaging during I-131 radioimmunotherapy) included tumors of varying size, shape, and contrast. OLINDA calculations were first carried out using the baseline tumor volume and residence time from SPECT/CT imaging during 6 days post-tracer and 8 days post-therapy. Next, the OLINDA calculation was split over multiple time periods and summed to get the total dose, which accounted for the changes in tumor size. Results from the second calculation were compared with results determined by coupling SPECT/CT images with DPM Monte Carlo algorithms. Results from the OLINDA calculation accounting for changes in tumor size were almost always higher (median 22%, range -1%-68%) than the results from OLINDA using the baseline tumor volume because of tumor shrinkage. There was good agreement (median -5%, range -13%-2%) between the OLINDA results and the self-dose component from Monte Carlo calculations, indicating that tumor shape effects are a minor source of error when using the sphere model. However, because the sphere model ignores cross-irradiation, the OLINDA calculation significantly underestimated (median 14%, range 2%-31%) the total tumor absorbed dose compared with Monte Carlo. These results show that when the quantity of interest is the mean tumor absorbed dose, the unit density sphere model is a practical alternative to Monte Carlo for some applications. For applications requiring higher accuracy, computer-intensive Monte Carlo calculation is needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90433/1/cbr-2E2011-2E0965.pd

“I Knew What I Was Going to School For”: A Mixed Methods Examination of Black College Students’ Racialized Experiences at a Southern PWI

Researchers have consistently documented a range of racialized inputs and outcomes in U.S. higher education. Those dynamics appear especially salient, and their consequences especially pronounced in the U.S. region often referred to as the Deep South. This overwhelming body of evidence, including the documented patterns of racial segregation in Deep South higher education, disparate opportunities and advantages, and inequitable outcomes, offers less insight on how Black students make sense of their experiences. This study used explanatory mixed methods to document racialized differences in campus experiences and to understand how Black students made sense of and navigated those racialized experiences. Our quantitative results point to educational disparities, both in terms of experiences and perceptions of the campus climate. The qualitative findings indicate that Black students made sense of those disparities by conceptualizing of racialized treatment as a benevolent preparation for the ‘real world,’ by internalizing and reproducing hegemonic discourse, and by rationalizing their experiences as developmentally necessary. We offer implications for higher education faculty and staff, who must work to disrupt these racialized and white supremacist patterns in higher education

Biokinetics and dosimetry of commonly used radiopharmaceuticals in diagnostic nuclear medicine – a review

Purpose The impact on patients’ health of radiopharmaceuticals in nuclear medicine diagnostics has not until now been evaluated systematically in a European context. Therefore, as part of the EU-funded Project PEDDOSE. NET (www.peddose.net), we review and summarize the current knowledge on biokinetics and dosimetry of commonly used diagnostic radiopharmaceuticals. Methods A detailed literature search on published biokinetic and dosimetric data was performed mostly via PubMed (www.ncbi.nlm.nih.gov/pubmed). In principle the criteria for inclusion of data followed the EANM Dosimetry Committee guidance document on good clinical reporting. Results Data on dosimetry and biokinetics can be difficult to find, are scattered in various journals and, especially in paediatric nuclear medicine, are very scarce. The data collection and calculation methods vary with respect to the time-points, bladder voiding, dose assessment after the last data point and the way the effective dose was calculated. In many studies the number of subjects included for obtaining biokinetic and dosimetry data was fewer than ten, and some of the biokinetic data were acquired more than 20 years ago. Conclusion It would be of interest to generate new data on biokinetics and dosimetry in diagnostic nuclear medicine using state-of-the-art equipment and more uniform dosimetry protocols. For easier public access to dosimetry data for diagnostic radiopharmaceuticals, a database containing these data should be created and maintained