Effect of Spatial and Spectral Scaling on Joint Characterization of the Spectral Mixture Residual: Comparative Analysis of AVIRIS and WorldView-3 SWIR for Geologic Mapping in Anza-Borrego Desert State Park.

A geologic map is both a visual depiction of the lithologies and structures occurring at the Earth's surface and a representation of a conceptual model for the geologic history in a region. The work needed to capture such multifaced information in an accurate geologic map is time consuming. Remote sensing can complement traditional primary field observations, geochemistry, chronometry, and subsurface geophysical data in providing useful information to assist with the geologic mapping process. Two novel sources of remote sensing data are particularly relevant for geologic mapping applications: decameter-resolution imaging spectroscopy (spectroscopic imaging) and meter-resolution multispectral shortwave infrared (SWIR) imaging. Decameter spectroscopic imagery can capture important mineral absorptions but is frequently unable to spatially resolve important geologic features. Meter-resolution multispectral SWIR images are better able to resolve fine spatial features but offer reduced spectral information. Such disparate but complementary datasets can be challenging to integrate into the geologic mapping process. Here, we conduct a comparative analysis of spatial and spectral scaling for two such datasets: one Airborne Visible/Infrared Imaging Spectrometer-Classic (AVIRIS-classic) flightline, and one WorldView-3 (WV3) scene, for a geologically complex landscape in Anza-Borrego Desert State Park, California. To do so, we use a two-stage framework that synthesizes recent advances in the spectral mixture residual and joint characterization. The mixture residual uses the wavelength-explicit misfit of a linear spectral mixture model to capture low variance spectral signals. Joint characterization utilizes nonlinear dimensionality reduction (manifold learning) to visualize spectral feature space topology and identify clusters of statistically similar spectra. For this study area, the spectral mixture residual clearly reveals greater spectral dimensionality in AVIRIS than WorldView (99% of variance in 39 versus 5 residual dimensions). Additionally, joint characterization shows more complex spectral feature space topology for AVIRIS than WorldView, revealing information useful to the geologic mapping process in the form of mineralogical variability both within and among mapped geologic units. These results illustrate the potential of recent and planned imaging spectroscopy missions to complement high-resolution multispectral imagery-along with field and lab observations-in planning, collecting, and interpreting the results from geologic field work.

Do Admissions Multiple Mini-Interview and Traditional Interview Scores Predict Subsequent Academic Performance? A Study of Five California Medical Schools.

PURPOSE: To compare the predictive validities of medical school admissions multiple mini-interviews (MMIs) and traditional interviews (TIs). METHOD: This longitudinal observational study of 2011-2013 matriculants to five California public medical schools examined the associations of MMI scores (two schools) and TI scores (three schools) with subsequent academic performance. Regression models adjusted for sociodemographics and undergraduate academic metrics examined associations of standardized mean MMI and TI scores with United States Medical Licensing Examination Step 1 and Step 2 Clinical Knowledge (CK) scores and, for required clerkships, with mean National Board of Medical Examiners Clinical Science subject (shelf) exam score and number of honors grades. RESULTS: Of the 1,460 medical students, 746 (51.1%) interviewed at more than one study school; 579 (39.7%) completed at least one MMI and at least one TI. Neither interview type was associated with Step 1 scores. Higher MMI scores were associated with more clerkship honors grades (adjusted incidence rate ratio [AIRR] 1.28 more [95% CI 1.18, 1.39; P < .01] per SD increase) and higher shelf exam and Step 2 CK scores (adjusted mean 0.73 points higher [95% CI 0.28, 1.18; P < .01] and 1.25 points higher [95% CI 0.09, 2.41; P = .035], respectively, per SD increase). Higher TI scores were associated only with more honors grades (AIRR 1.11 more [95% CI 1.01, 1.20; P = .03] per SD increase). CONCLUSIONS: MMI scores were more strongly associated with subsequent academic performance measures than were TI scores.

Medical School Applicant Characteristics Associated With Performance in Multiple Mini-Interviews Versus Traditional Interviews: A Multi-Institutional Study.

PURPOSE: To examine applicant characteristics associated with multiple mini-interview (MMI) or traditional interview (TI) performance at five California medical schools. METHOD: Of the five California Longitudinal Evaluation of Admission Practices consortium schools, three used TIs and two used MMIs. Schools provided retrospective data on 2011-2013 admissions cycle interviewees: age, gender, race/ethnicity (underrepresented in medicine [UIM] or not), disadvantaged (DA) status, undergraduate GPA, Medical College Admission Test (MCAT) score, and interview score (standardized as z score; mean = 0; SD = 1). Adjusted linear regression analyses, stratified by interview type, examined associations with interview performance. RESULTS: The 4,993 applicants who completed 7,516 interviews included 931 (18.6%) UIM and 962 (19.3%) DA individuals; 3,226 (64.6%) had only 1 interview. Mean age was 24.4 (SD = 2.7); mean GPA and MCAT score were 3.72 (SD = 0.22) and 33.6 (SD = 3.7), respectively. Older age, female gender, and number of prior interviews were associated with better performance on both MMIs and TIs. Higher GPA was associated with lower MMI scores (z score, per unit GPA = -0.26; 95% CI = -0.45, -0.06) but unrelated to TI scores. DA applicants had higher TI scores (z score = 0.17; 95% CI = 0.07, 0.28) but lower MMI scores (z score = -0.18; 95% CI = -0.28, -0.08) than non-DA applicants. Neither UIM status nor MCAT score was associated with interview performance. CONCLUSIONS: These findings have potentially important workforce implications, particularly regarding MMI performance of DA applicants, and illustrate the need for other multi-institutional studies.