19 resultados para Over Head Line Design
Resumo:
Background. The childhood obesity epidemic has disproportionately impacted the lives of low-income, minority preschoolers and their families. Research shows that parents play a major role as "gatekeepers" who control what food is brought into the home and as role models for dietary practices. Currently, there is limited research regarding ethnic differences in families of low-income preschoolers. ^ Objective. The objective of this study was to look at ethnic differences in food availability at home among the low-income families of Hispanic and African American preschoolers attending Head Start centers in Harris County, Texas. ^ Design/Subjects. Descriptive data on food availability at home between Hispanic and African American families were used and analyzed for this study. Parents or primary caregivers (n = 718) of children enrolled at Head Start Centers in Houston, Texas completed the Healthy Home Survey. ^ Methods. In the Healthy Home Survey, participants were asked to answer open-ended questions regarding various types of foods currently available at home, such as fresh, canned or jarred, dried and frozen fruits; fresh, canned or jarred, and frozen vegetables; salty snacks, sweet snacks, candy, and soda. Descriptive analyses were conducted to identify significant differences between Hispanics and African Americans via a paired t-test to compare the means of variables between the study groups and a Pearson's chi-square or Fischer's exact (if cell size was <5) test calculated for food availability (food types) between ethnicities to determine differences in distributions. ^ Results. Although both Hispanics and African Americans reported having all categories of food types at home, there were statistically significant differences between ethnic groups. Hispanics were more likely to have fresh fruits and vegetables at home than African Americans. At the same time, more African American families reported having canned or jarred fruits and canned green/leafy vegetables than Hispanics. More Hispanic families reported having diet, regular, and both diet and regular sodas available compared to African American families. However, high percentages of unhealthy foods (including snacks and candy) were reported by both ethnicities. ^ Conclusions. The findings presented in this study indicate the implicit ethnic differences that exist in the food availability among low-income families of Hispanic and African American preschoolers. Future research should investigate the associations between food availability and children's weight status by ethnicity to identify additional differences that may exist.^
Resumo:
High-resolution, small-bore PET systems suffer from a tradeoff between system sensitivity, and image quality degradation. In these systems long crystals allow mispositioning of the line of response due to parallax error and this mispositioning causes resolution blurring, but long crystals are necessary for high system sensitivity. One means to allow long crystals without introducing parallax errors is to determine the depth of interaction (DOI) of the gamma ray interaction within the detector module. While DOI has been investigated previously, newly available solid state photomultipliers (SSPMs) well-suited to PET applications and allow new modules for investigation. Depth of interaction in full modules is a relatively new field, and so even if high performance DOI capable modules were available, the appropriate means to characterize and calibrate the modules are not. This work presents an investigation of DOI capable arrays and techniques for characterizing and calibrating those modules. The methods introduced here accurately and reliably characterize and calibrate energy, timing, and event interaction positioning. Additionally presented is a characterization of the spatial resolution of DOI capable modules and a measurement of DOI effects for different angles between detector modules. These arrays have been built into a prototype PET system that delivers better than 2.0 mm resolution with a single-sided-stopping-power in excess of 95% for 511 keV g's. The noise properties of SSPMs scale with the active area of the detector face, and so the best signal-to-noise ratio is possible with parallel readout of each SSPM photodetector pixel rather than multiplexing signals together. This work additionally investigates several algorithms for improving timing performance using timing information from multiple SSPM pixels when light is distributed among several photodetectors.
Resumo:
In the current climate of escalating health care costs, defining value and accurately measuring it are two critical issues affecting not only the future of cancer care in particular but also the future of health care in general. Specifically, measuring and improving value in cancer-related health care are critical for continued advancements in research, management, and overall delivery of care. However, in oncology, most of this research has focused on value as it relates to insurance industry and payment reform, with little attention paid to value as the output of clinical interventions that encompass integrated clinical teams focusing on the entire cycle of care and measuring objective outcomes that are most relevant to patients. ^ In this study, patient-centered value was defined as health outcomes achieved per dollar spent, and calculated using objective functional outcomes and total care costs. The analytic sample comprised patients diagnosed with three common head and neck cancers—cancer of the larynx, oral cavity, and oropharynx—who were treated in an integrated tertiary care center over an approximately 10-year period. The results of this study provide initial empirical data that can be used to assess and ultimately to help improve the quality and value of head and neck cancer care, and more importantly they can be used by patients and clinicians to make better-informed decisions about care, particularly what therapeutic services and outcomes matter the most to patients.^
Resumo:
Head and Neck Squamous Cell Carcinoma (HNSCC) is the sixth common malignancy in the world, with high rates of developing second primary malignancy (SPM) and moderately low survival rates. This disease has become an enormous challenge in the cancer research and treatments. For HNSCC patients, a highly significant cause of post-treatment mortality and morbidity is the development of SPM. Hence, assessment of predicting the risk for the development of SPM would be very helpful for patients, clinicians and policy makers to estimate the survival of patients with HNSCC. In this study, we built a prognostic model to predict the risk of developing SPM in patients with newly diagnosed HNSCC. The dataset used in this research was obtained from The University of Texas MD Anderson Cancer Center. For the first aim, we used stepwise logistic regression to identify the prognostic factors for the development of SPM. Our final model contained cancer site and overall cancer stage as our risk factors for SPM. The Hosmer-Lemeshow test (p-value= 0.15>0.05) showed the final prognostic model fit the data well. The area under the ROC curve was 0.72 that suggested the discrimination ability of our model was acceptable. The internal validation confirmed the prognostic model was a good fit and the final prognostic model would not over optimistically predict the risk of SPM. This model needs external validation by using large data sample size before it can be generalized to predict SPM risk for other HNSCC patients. For the second aim, we utilized a multistate survival analysis approach to estimate the probability of death for HNSCC patients taking into consideration of the possibility of SPM. Patients without SPM were associated with longer survival. These findings suggest that the development of SPM could be a predictor of survival rates among the patients with HNSCC.^