Performance evaluation of two CZT gamma ray imaging systems

The purpose of this research was to evaluate the performance of the imaging characteristics of two versions of a cadmium zinc telluride (CZT) gamma radiation detector system called the Laboratory Radioactive Assay Tracer (LabRAT). The performance evaluation follows the National Electrical Manufacturers Association standards for pixellated detector cameras. The LabRAT detector system hardware was developed by Mosaic Imaging Technology, Inc. LabRAT is a portable nuclear medicine imaging detector system intended for small field of view applications such as small animal imaging, portable radioisotope imaging in emergency room or intensive care units, and as an instruction tool for radiology residents and physics students. The tests performed include the measurement of count rate performance, per-pixel and composite energy resolution, uniformity of detector response, extrinsic spatial resolution, linearity, and integral and differential uniformity. Prior to the performance evaluation acquisition software was developed to operate the detector, including initializing the detector, performing data acquisition and displaying images and energy spectra. One of the systems had a better composite energy resolution due to the fact that the locations of photopeak centers for the individual pixels in that detector were consistently more uniform than the locations for the other detector. The energy resolution attainable for individual pixels is good, but due to limitations in user control over tuning of individual pixels, the composite energy resolution values were higher than expected for both systems. In practice, energy windows must be applied on a per-pixel basis. Spatial uniformity is worse than for typical scintillator-based gamma cameras, while extrinsic spatial resolution is satisfactory

Steering an AIDS-free course : personal prevention strategies of young people in Tanzania

This thesis presents an exploration of the personal HIV/AIDS prevention strategies of young adolescents in Tanzania. Most of the 209 research participants were aged 10-15. They included students, those out of school and ‘street children’. In this multiple method study, the young people participated in focus groups, individual interviews, questionnaires, ranking exercises, and write-and-draw exercises. Most of the participants were motivated to prevent HIV/AIDS and were able to communicate credible strategies. Many participants described tactics related to refraining from sex. Males tended to describe sexual temptation in terms of their own sexual desires, and refraining from sex in terms of the management of those desires. Females tended to describe sexual temptation in terms of the benefits males might offer in exchange for sex and the possible risks of agreement or refusal. Females described refraining from sex in terms of politely refusing, eluding and outsmarting males, and avoiding situations where rape might occur. Male participants who discussed penile-anal sex nevertheless seemed to associate HIV transmission mainly with heterosexual relationships and penile-vaginal sex. In further findings, many participants described tactics related to the prevention of blood-borne infection. Some participants mentioned testing and transmission in mother-to-child and caring relationships. Although most participants agreed in theory that condoms were a good way to prevent HIV/AIDS and that it was acceptable for a male or female to ask a partner to take an HIV test before having sex, relatively few participants included testing or condoms in their strategies. Most pilot study participants were knowledgeable about some aspects of prevention, but demonstrated no knowledge of HIV prevalence. This study indicates a role that national and international leaders, policy makers, teachers, parents and others might play to encourage young adolescents to steer an AIDS-free course, by supporting young people to build on their existing personal strategies of prevention, and to develop and adapt their strategies as they mature. That may support the young people to delay the sexual debut, to prevent HIV/AIDS when beginning and maintaining sexual relationships, to refrain from sex, if they wish, after the sexual debut, and to reduce the incidence of blood-borne transmission, mother-to-child transmission, and transmission when caring for others who may be affected

Analysis of Ice Plains of Filchner/Ronne Ice Shelf Using ICESat Data

We use repeat-track laser altimeter data from the Ice, Cloud, and land Elevation Satellite (ICESat) to map the grounding zone of Filchner/Ronne Ice Shelf (FRIS), Antarctica. Repeated passes of ICESat reveal ice flexure in the grounding zone occurs as the ice shelf responds to ocean height changes due primarily to tides. In the course of our mapping, we have confirmed or identified three major "ice plains", regions of low surface slope near the GZ where the ice is close to hydrostatic equilibrium: one on Institute Ice Stream, another to its east, and another west of Foundation Ice Stream. The vertical information from repeated ICESat tracks enables us to study the topography and flexure characteristics across these three ice plains, and we use this to develop a classification scheme for ice plains based on their surface topography and their state of flotation. We show that one of these ice plains indicates changes in lateral extent on short time-scales, depending on the state of the ocean tide. Understanding the location and nature of ice plains is important for ice sheet modeling, since they add uncertainty to the absolute boundary between floating and grounded ice

Strengthening the Relationship between Undergraduate Professional Preparation Programs in Parks, Recreation, and Tourism and Graduate Leisure Studies

This article stems from a conversation among academic leaders of graduate-oriented departments of parks, recreation, and tourism across North America who participated in an administrator summit at Zion Ponderosa Resort in southern Utah September 23-26, 2010. The University of Utah’s Department of Parks, Recreation, and Tourism hosted the summit, and among the many topics discussed was the need to strengthen the relationship between undergraduate professional preparation programs in parks, recreation, and tourism and graduate leisure studies. In many respects, the tension between undergraduate and graduate programs reflects the tension between research universities and the world of professional practice. We examine this tension in both contexts and recommend specific courses of action to relieve it

The Australian Institute of Family Studies Evaluation of the 2006 Family Law Reforms: Key findings

The Australian Institute of Family Studies' Evaluation of the 2006 family law reforms was released in January 2010. It is based on an extensive amount of empirical research, unprecedented in Australia and arguably internationally, comprising 17 separate studies involving 28,000 people, 1724 court files, administrative data and legal analysis. This article presents some key findings of the Evaluation. Specifically, the Evaluation found that for the majority of families, the family law system is working satisfactorily. At the same time however, the Evaluation findings underline the existence of complex issues, including family violence and child abuse concerns, mental health problems and substance misuse which affect many families that rely on the federal family law system^ for assistance. While the introduction of family dispute resolution with exceptions+ has resulted in more disputes being resolved without court action, there is a need for refinement of processes and understandings with respect to cases that are unsuitable for such processes or cases that require additional support in order for disputes to be resolved safely and responsibly. Similarly, while children in shared care represent a minority overall, and while the majority of families with shared care appear to be doing well, there is evidence that these arrangements are sometimes being made even in circumstances where parents have safety concerns, with adverse consequences for the well-being of children