Means to achieve wide swath widths in synthetic aperture satellite borne radars

The radar range equation including processing gains for pulse compression and synthetic aperture generation was the starting point. System geometry considerations were introduced. For simplicity, flat earth geometry was used, although it was realized that this was not a good model for satellite-borne radars. Next, the constraints were introduced. These included those needed to avoid ambiguities in both range and azimuth, those needed to acheive the desired resolution, and those needed to achieve the desired swath width

Studies Directed Toward the Achievement of Wide Swathwidths in Synthetic Aperture Radar

Studies to achieve wide swath widths in Synthetic Aperture Radar are described. The use of multiple beams in range and/or azimuth is considered. Radar system parameters for a number of cases are computed

Synthetic Aperture Radar (SAR) data processing

The available and optimal methods for generating SAR imagery for NASA applications were identified. The SAR image quality and data processing requirements associated with these applications were studied. Mathematical operations and algorithms required to process sensor data into SAR imagery were defined. The architecture of SAR image formation processors was discussed, and technology necessary to implement the SAR data processors used in both general purpose and dedicated imaging systems was addressed

Statin Discontinuation among Nursing Home Residents with Advanced Dementia

Background: Statin use in elderly individuals with life-limiting illness such as advanced dementia is controversial. Objective: To describe factors associated with statin discontinuation and estimate impact of discontinuation on 28-day hospitalizations in nursing home (NH) residents with advanced dementia. Methods: Retrospective cohort study of NH residents ≥ 65 years with recent progression to advanced dementia from 5 large U.S. states drawn from the 2007-2008 Minimum Data Set 2.0. We identified residents using statins. Clinical characteristics and 28-day hospitalization risk were compared for residents discontinuing and continuing statins. Multivariable Cox proportional hazard models identified factors associated with time to statin discontinuation and time to hospitalization. Sensitivity analysis using self-controlled case series examined the role of confounding-by-indication on risk estimation from the cohort approach. Results: Of 10,212 residents with decline to advanced dementia, 16.6% were prescribed statins (n=1,699). Statin users had mean age of 83.1 yrs, 68.9% were female, and mean medication burden was 10.3 (SD 4.8, range 1-31). Over one-third (n=632) discontinued in follow-up. Median time to discontinuation was 36 days after decline to advanced dementia (IQR [25%, 75%]: 12 days, 110 days). After adjustment, factors independently associated with increased hazard of discontinuation included residence in a NH in Florida relative to California, hospitalization in the 30 days prior to decline to advanced dementia, greater medication burden, and having cancer. The 28-day hospitalization risk was higher for residents discontinuing statins compared to continuing (adjusted hazard ratio = 1.78, CI 1.61,2.58). The SCCS estimate for 28-day hospitalization risk following statin discontinuation compared to a 28-day pre-discontinuation control period was lower than the cohort estimate (IRR= 0.79, CI 0.76, 0.83). Conclusion: A significant proportion of nursing home residents with dementia who use statins when they progress to advanced stage disease discontinue use. Hospitalization outcomes following discontinuation differ depending on method of estimation

Effectiveness of the Volunteer Family Connect Program in reducing isolation of vulnerable families and supporting their parenting: randomized controlled trial with intention-to-treat analysis of primary outcome variables

Background: Volunteer home visiting is a widely adopted community-based approach to support families by linking isolated or vulnerable families with community volunteers who visit their homes weekly over approximately 12 months. This study seeks to robustly evaluate the effectiveness of this model of support for families with young children. Objective: This paper reports the intention-to-treat analysis of primary and secondary outcomes for a pragmatic randomized controlled trial (RCT) of the Volunteer Family Connect intervention, a volunteer home-visiting program designed to support families with young children who experience social isolation or a lack of parenting confidence and skills. Methods: The RCT was conducted across seven sites in Australia. Overall, 341 families were recruited: 169 intervention (services as usual+volunteer home visits) and 172 control (services as usual) families. Intervention families received the program for 3-12 months. Participants were invited to complete six data collection points over a 15-month period. Primary outcomes were community connectedness and parenting competence. Secondary outcomes included parent physical and mental health, general parent wellbeing, parent empowerment, the sustainability of family routines, and the parent-child relationship. According to the protocol, the program would be judged to be effective if at least one of the primary outcomes was significantly positive and the other was neutral (ie, intervention families did not demonstrate positive or negative outcomes compared to the control group). Results: The intervention group demonstrated significant improvement in the primary outcome variable parenting sense of competence as compared to the control group. Overall, there was no significant difference between the intervention and control groups with regard to the primary outcome variable community connectedness, other than on the “Guidance” subscale of the Social Provisions Scale. Because there were statistically significant findings for the total score of one primary outcome variable “parenting sense of competence” and largely neutral findings for the primary outcome variable “community connectedness,” the program met the previously defined criteria for program effectiveness. In relation to secondary outcomes, intervention families reported significantly higher wellbeing and were significantly more likely to feel that life was improving. Conclusions: The Volunteer Family Connect intervention was considered an effective intervention, with a role to play on the landscape of services available to support vulnerable families with young children

Health Information Seeking on Behalf of Others: Characteristics of ‘Surrogate Seekers’

Understanding the health information seeking behaviors of surrogate seekers (those who seek health information for others) may guide efforts to reach disadvantaged populations. We used 2011-2012 data from the Health Information National Trends Survey to describe the behaviors of online surrogate seekers. Respondents were asked about their use of the Internet for surrogate seeking over the prior 12 months. Data were weighted to calculate population estimates. Compared to those who sought health information online for only themselves, surrogate seekers were more likely to live in households with others (weighted percent 89.4% vs. 82.5% of self-seekers; p \u3c 0.05); no significant differences in gender, race, income or education were observed. Surrogate seekers were more likely to report: visits to social networking sites to read and share about medical topics; participation in online health support groups and downloading of health information to electronic devices. On multivariate analysis, those who had looked online for a healthcare provider were more likely to be surrogate seekers (OR 1.67, 95% CI 1.08-2.59). Our results offer insight for leveraging health communication efforts to reach populations who rely upon surrogate seekers for health information

Who Opens Alerts to Physicians? (And Who Doesn’t?)

Background: Electronic medical records (EMR) provide opportunities to implement systems of information flow, such as alerts to providers. Methods: Within a group practice with an EMR, we conducted a trial of automated alerts to the in-baskets of primary care physicians and staff when patients were discharged from hospital to home. We generated alerts for new medications or monitoring needs. Staff received alerts to schedule office visits. Using EMR “digital crumbs”, we tracked when alerts were viewed. We analyzed the impact of physician age, gender, department, and employment status (full-time, part-time) as well as patient conditions (age, gender, comorbidity, and number of office visits in the previous year) on timely opening. Results: Of 763 alerts to physicians, 616 (81%) were opened within one day. Characteristics associated with timely opening were age \u3c 50 (OR 1.7, 95% CI 1.1, 2.6) and full-time employment (OR 2.9, 95% CI 1.6, 5.2). Of 1928 alerts to staff, 1173 (61%) were opened within one day. Staff of male physicians were more likely to open the alerts within one day (OR 1.8, 95% CI 1.4, 2.4) as were working for the Family Medicine department (OR 1.9, 95% CI 1.3, 2.6) or a sub-specialty department (OR 16.6, 95% CI 2.3, 122.3). Staff of full-time physicians were less likely to open alerts (OR 0.64, 95% CI 0.47, 0.87). Adjusting for patient characteristics had no impact on results. Conclusion: Special efforts may be required to reach physicians working part-time and older physicians. Characteristics related to staff opening of alerts are specific to this group practice, but the high level of variability across physician types and departments is likely to be an issue in many settings. Design of a system directed at reaching staff quickly may require in-depth assessment of work flow and communication patterns in clinical department

Investigating the Nucleic Acid Interactions of Histone-Derived Antimicrobial Peptides

While many antimicrobial peptides (AMPs) disrupt bacterial membranes, some translocate into bacteria and interfere with intracellular processes. Buforin II and DesHDAP1 are thought to kill bacteria by interacting with nucleic acids. Molecular modeling and experimental measurements were used to show that neither nucleic acid binding peptide selectively binds DNA sequences. Simulations and experiments also showed that changing lysines to arginines enhances DNA binding, suggesting that including additional guanidinium groups is a potential strategy to engineer more potent AMPs. Moreover, the lack of binding specificity may make it more difficult for bacteria to evolve resistance to these and other similar AMPs

Validation of Acute Myocardial Infarction (AMI) in the FDA’s Mini-Sentinel Distributed Database

The Food and Drug Administration’s (FDA) Mini-Sentinel is a pilot program that aims to conduct active surveillance to detect and refine safety signals that emerge for marketed medical products. The purpose of this Mini-Sentinel AMI Validation project was to: (a) develop and design an abstraction and adjudication process to use when full text medical record review is required to confirm a coded diagnosis; and (b) to test this approach by validating a code algorithm for acute myocardial infarction (AMI)

The association of dietary quality with colorectal cancer among normal weight, overweight and obese men and women: a prospective longitudinal study in the USA

OBJECTIVE: Lower body mass index (BMI) and higher dietary quality reduce the risk of colorectal cancer (CRC). A full understanding of how these associations vary by sex and weight is lacking. METHODS: We used data from the National Institutes of Health - American Association of Retired Persons (NIH)-AARP) Diet and Health Study for 398 458 persons who were 50-71 years old in 1995-1996 and followed through 2006. Exposures were dietary quality as reflected by the Mediterranean Diet, the Healthy Eating Index-2010 and the Dietary Approaches to Stop Hypertension score, stratified by BMI category. The outcome was CRC diagnosis from cancer registry data. Cox regression models were adjusted for disease risk factors. RESULTS: Over a mean duration of 123 months of follow-up, there were 6515 new diagnoses of CRC (1953 among the normal weight, 2924 among the overweight and 1638 among the obese; 4483 among men and 2032 among women). For normal weight and overweight men, we found a strong dose-response pattern for the association of increasing quintile of dietary quality with decreasing risk of CRC; this pattern was observed for obese men as well, but less consistently across the three measures of dietary quality. The findings were of smaller magnitude and less consistent for women but still suggesting associations of similar direction. CONCLUSION: We observed that increased dietary quality was associated with lower risk of incident CRC up to 10 years later for men regardless of baseline weight category