Cognitive Efficiency Considerations for Good Graphic Design

Larkin and Simon's (1987) analysis of how graphical representations support task performance is applied to designing graphical displays that streamline information-processing tasks. Theoretically this streamlining is done by designing external data structures that (a) allow users to substitute less effortful visual operators for more effortful logical operators, and (b) reduce search for needed information.A design program called BOZ is used to produce four alternative displays of airline schedule information to support a task of making airline reservations. W e postulate several procedures that use visual operators to perform the task using the different graphics. The number of times each operator is executed provides one measure of task difficulty (for a procedure and graphic). A second measure is the difficulty of executing each operator. Seven subjects performed the airiine reservation task using each of the four graphics. Response times for the different graphics differ by a factor of two, which is statistically highly significant. Detailed data analyses suggest that these differences arise through substitution of visual operators for logical ones and through the use of visual cues that help reduce search. These analyses provide quantitative estimates of the time saved through operator substitutions

Understanding the Astrophysics of Galaxy Evolution: the role of spectroscopic surveys in the next decade

Over the last decade optical spectroscopic surveys have characterized the low redshift galaxy population and uncovered populations of star-forming galaxies back to z ~ 7. This work has shown that the primary epoch of galaxy building and black hole growth occurs at redshifts of 2 to 3. The establishment of the concordance LCDM cosmology shifted the focus of galaxy population studies from constraining cosmological parameters to characterizing the processes which regulate the formation and evolution of galaxies.In the next decade, high redshift observers will attempt to formulate a coherent evolutionary picture connecting galaxies in the high redshift Universe to galaxies today. In order to link galaxy populations at different redshifts, we must not only characterize their evolution in a systematic way, we must establish which physical processes are responsible for it. Considerable progress has already been made in understanding how galaxies evolved from z ~ 1 to the present day. Large spectroscopic surveys in the near infrared are required to push these studies back towards the main epoch of galaxy building. Only then will we understand the full story of the formation of L* galaxies like our own Milky Way. A large near-IR spectroscopic survey will also provide the calibration needed to avoid systematics in the large photometric programs proposed to study the nature of dark matter and dark energy. We provide an outline design for a multi-object 0.4 to 1.8 micron spectrograph, which could be placed on an existing telescope, and which would allow a full characterization of the galaxy population out to z ~ 2. We strongly recommend a serious further study to design a real instrument, which will be required for galaxy formation studies to advance to the next frontier.Comment: White paper, primary author J.E. Gunn, submitted to Astro2010 Decadal Survey, see http://www7.nationalacademies.org/bpa/Astro2010_SWP_byTitle.htm

Prevalence of Microvascular and Macrovascular Disease in the Glycemia Reduction Approaches in Diabetes - A Comparative Effectiveness (GRADE) Study Cohort

Aims: The Glycemia Reduction Approaches in Diabetes - A Comparative Effectiveness (GRADE) trial is a randomized clinical trial comparing glycemic effects of four diabetes medications added to metformin in type 2 diabetes (T2D). Microvascular and macrovascular diseases are secondary outcomes. We evaluated the prevalence and risk factor relationships for microvascular and macrovascular complications in the GRADE cohort at study entry. Methods: Complication prevalence and risk factors were analyzed based on data from screening in all consenting participants meeting GRADE eligibility. Logistic regression and Z-statistics were used to assess risk factor relationships with complications. Results: We enrolled 5047 T2D participants [mean age 57 years; 36% female; mean known T2D duration 4 years (all < 10 years); mean HbA1c 8.0% (∼64 mmol/mol) at screening]. Urinary albumin/creatinine ratio (ACR) ≥ 30 mg/gram was present in 15.9% participants; peripheral neuropathy (by Michigan Neuropathy Screening Instrument) in 21.5%; cardiovascular autonomic neuropathy by electrocardiography-derived indices in 9.7%; self-reported retinopathy in 1.0%. Myocardial infarction ascertained by self-report or electrocardiogram was present in 7.3%, and self-reported history of stroke in 2.0%. Conclusions: In the GRADE cohort with < 10 years of T2D and a mean HbA1c of 8.0%, diabetes complications were present in a substantial fraction of participants, more so than might otherwise have been expected

THE AFFORDABLE CARE ACT AND AMBULANCE RESPONSE TIMES

This study contributes to the literature on supply-side adjustments to insurance expansions by examining the effect of the Affordable Care Act (ACA) on ambulance response times. Exploiting temporal and geographic variation in the implementation of the ACA as well as pre-treatment differences in uninsured rates, we estimate that the expansions of private and Medicaid coverage under the ACA combined to slow ambulance response times by an average of 19%. We conclude that, through extending coverage to individuals who, in its absence, would not have availed themselves of emergency medical services, the ACA added strain to emergency response systems