A General Geometric Fourier Transform

The increasing demand for Fourier transforms on geometric algebras has resulted in a large variety. Here we introduce one single straight forward definition of a general geometric Fourier transform covering most versions in the literature. We show which constraints are additionally necessary to obtain certain features like linearity or a shift theorem. As a result, we provide guidelines for the target-oriented design of yet unconsidered transforms that fulfill requirements in a specific application context. Furthermore, the standard theorems do not need to be shown in a slightly different form every time a new geometric Fourier transform is developed since they are proved here once and for all.Comment: First presented in Proc. of The 9th Int. Conf. on Clifford Algebras and their Applications, (2011

Peer navigation improves diagnostic follow-up after breast cancer screening among Korean American women: results of a randomized trial

To test an intervention to increase adherence to diagnostic follow-up tests among Asian American women. Korean American women who were referred for a diagnostic follow-up test (mainly diagnostic mammograms) and who had missed their follow-up appointment were eligible to participate in the study. Women from two clinics (n = 176) were randomly allocated to a usual care control arm or a peer navigator intervention arm. A 20-min telephone survey was administered to women in both study arms six months after they were identified to assess demographic and socio-economic characteristics and the primary outcome, self-reported completion of the recommended follow-up exam. Among women who completed the survey at six-month follow-up, self-reported completion of follow-up procedures was 97% in the intervention arm and 67% in the control arm (p < 0.001). Based on an intent-to-treat analysis of all women who were randomized and an assumption of no completion of follow-up exam for women with missing outcome data, self-reported completion of follow-up was 61% in the intervention arm and 46% in the usual care control arm (p < 0.069). Our results suggest that a peer navigator intervention to assist Korean American women to obtain follow-up diagnostic tests after an abnormal breast cancer screening test is efficacious

Structural results for quaternionic Gabor frames

We study quaternionic Gabor frames based on the two-sided quaternionic windowed Fourier transform. Since classical Hilbert space based methods do not work in this case we introduce appropriated versions of translation and modulation operators. We prove Janssen’s and Walnut’s representations, as well as modified versions of the Wexler–Raz biorthogonality and Ron–Shen duality based on the concept of correlation function. We end up with a characterization of tight quaternionic Gabor frames.publishe

Collaborative planning approach to inform the implementation of a healthcare manager intervention for hispanics with serious mental illness: a study protocol

Background: This study describes a collaborative planning approach that blends principles of community-based participatory research (CBPR) and intervention mapping to modify a healthcare manager intervention to a new patient population and provider group and to assess the feasibility and acceptability of this modified intervention to improve the physical health of Hispanics with serious mental illness (SMI) and at risk for cardiovascular disease (CVD). Methods: The proposed study uses a multiphase approach that applies CBPR principles and intervention-mapping steps--an intervention-planning approach--to move from intervention planning to pilot testing. In phase I, a community advisory board composed of researchers and stakeholders will be assembled to learn and review the intervention and make initial modifications. Phase II uses a combination of qualitative methods--patient focus groups and stakeholder interviews--to ensure that the modifications are acceptable to all stakeholders. Phase III uses results from phase II to further modify the intervention, develop an implementation plan, and train two care managers on the modified intervention. Phase IV consists of a 12-month open pilot study (N = 30) to assess the feasibility and acceptability of the modified intervention and explore its initial effects. Lastly, phase V consists of analysis of pilot study data and preparation for future funding to develop a more rigorous evaluation of the modified intervention. Discussion: The proposed study is one of the few projects to date to focus on improving the physical health of Hispanics with SMI and at risk for CVD by using a collaborative planning approach to enhance the transportability and use of a promising healthcare manager intervention. This study illustrates how blending health-disparities research and implementation science can help reduce the disproportionate burden of medical illness in a vulnerable population

Improving healthcare empowerment through breast cancer patient navigation: a mixed methods evaluation in a safety-net setting

BACKGROUND: Breast cancer mortality rates in the U.S. remain relatively high, particularly among ethnic minorities and low-income populations. Unequal access to quality care, lower follow up rates, and poor treatment adherence contribute to rising disparities among these groups. Healthcare empowerment (HCE) is theorized to improve patient outcomes through collaboration with providers and improving understanding of and compliance with treatment. Patient navigation is a health care organizational intervention that essentially improves healthcare empowerment by providing informational, emotional, and psychosocial support. Patient navigators address barriers to care through multilingual coordination of treatment and incorporation of access to community services, support, and education into the continuum of cancer care. METHODS: Utilizing survey and qualitative methods, we evaluated the patient navigation program in a Northern California safety-net hospital Breast Clinic by assessing its impact on patients’ experiences with cancer care and providers’ perspectives on the program. We conducted qualitative interviews with 16 patients and 4 service providers, conducted approximately 66 hours of clinic observations, and received feedback through the self-administered survey from 66 patients. RESULTS: The role of the patient navigator at the Breast Clinic included providing administrative assistance, psychosocial support, improved knowledge, better understanding of treatment process, and ensuring better communication between patients and providers. As such, patient navigators facilitated improved collaboration between patients and providers and understanding of interdisciplinary care processes. The survey results suggested that the majority of patients across all ethnic backgrounds and age groups were highly satisfied with the program and had a positive perception of their navigator. Interviews with patients and providers highlighted the roles of a navigator in ensuring continuity of care, improving treatment completion rates, and reducing providers’ workload and waiting time. Uncertainty about the navigator’s role among the patients was a weakness of the program. CONCLUSIONS: Patient navigation in the Breast Clinic had a positive impact on patients’ experiences with care and healthcare empowerment. Clarifying uncertainties about the navigators’ role would aid successful outcomes

Social Relationships and Mortality Risk: A Meta-analytic Review

In a meta-analysis, Julianne Holt-Lunstad and colleagues find that individuals' social relationships have as much influence on mortality risk as other well-established risk factors for mortality, such as smoking

Time to definitive diagnosis of breast cancer in Latina and non-Hispanic white women: the six cities study

Time delay after an abnormal screening mammogram may have a critical impact on tumor size, stage at diagnosis, treatment, prognosis, and survival of subsequent breast cancer. This study was undertaken to evaluate disparities between Latina and non-Hispanic white (NHW) women in time to definitive diagnosis of breast cancer after an abnormal screening mammogram, as well as factors contributing to such disparities. As part of the activities of the National Cancer Institute (NCI)-funded Redes En Acción research network, clinical records of 186 Latinas and 74 NHWs who received abnormal screening mammogram results were reviewed to determine the time to obtain a definitive diagnosis. Data was obtained from participating clinics in six U.S. cities and included demographics, clinical history, and mammogram characteristics. Kaplan-Meier estimates and Cox proportional hazards models were used to test differences in median time to definitive diagnosis by ethnicity after adjusting for clinic site, demographics, and clinical characteristics. Time-to-event analysis showed that Latinas took 2.2 times longer to reach 50% definitively diagnosed with breast cancer relative to NHWs, and three times longer to reach 80% diagnosed (p=0.001). Latinas’ median time to definitive diagnosis was 60 days compared to 27 for NHWs, a 59% gap in diagnosis rates (adjusted Hazard Ratio [aHR] = 1.59, 95% CI = 1.09, 2.31; p=0.015). BI-RADS-4/5 women’s diagnosis rate was more than twice that of BI-RADS-3 (aHR = 2.11, 95% CI = 1.18, 3.78; p=0.011). Disparities in time between receipt of abnormal screening result and definitive diagnosis adversely affect Latinas compared to NHWs, and remain significant after adjusting for demographic and clinical variables. With cancer now the leading cause of mortality among Latinos, a greater need exists for ethnically and culturally appropriate interventions like patient navigation to facilitate Latinas’ successful entry into, and progression through, the cancer care system