ARTist: The Android Runtime Instrumentation and Security Toolkit

We present ARTist, a compiler-based application instrumentation solution for Android. ARTist is based on the new ART runtime and the on-device dex2oat compiler of Android, which replaced the interpreter-based managed runtime (DVM) from Android version 5 onwards. Since dex2oat is yet uncharted, our approach required first and foremost a thorough study of the compiler suite's internals and in particular of the new default compiler backend Optimizing. We document the results of this study in this paper to facilitate independent research on this topic and exemplify the viability of ARTist by realizing two use cases. Moreover, given that seminal works like TaintDroid hitherto depend on the now abandoned DVM, we conduct a case study on whether taint tracking can be re-instantiated using a compiler-based instrumentation framework. Overall, our results provide compelling arguments for preferring compiler-based instrumentation over alternative bytecode or binary rewriting approaches.Comment: 13 page

Evaluation of Cooper 12-Minute Walk/Run Test as a Marker of Cardiorespiratory Fitness in Young Urban Children with Persistent Asthma

Objective: To evaluate Cooper 12-minute run/walk test (CT12) as a one-time estimate of cardiorespiratory fitness and marker of fitness change compared with treadmill fitness testing in young children with persistent asthma. Design: A cohort of urban children with asthma participated in the asthma and exercise program and a subset completed pre- and postintervention fitness testing. Setting: Treadmill fitness testing was conducted by an exercise physiologist in the fitness laboratory at an academic children's hospital. CT12 was conducted in a college recreation center gymnasium. Participants: Forty-five urban children with persistent asthma aged 7 to 14 years participated in exercise interventions. A subset of 19 children completed pre- and postintervention exercise testing. Interventions: Participants completed a 9-week exercise program where they participated in either swimming or golf 3 days a week for 1 hour. A subset of participants completed fitness testing by 2 methods before and after program completion. Main Outcome Measures: CT12 results (meters), maximal oxygen consumption ((V) over doto(2)max) (mL.kg(-1).min(-1)), and treadmill exercise time (minutes). Results: CT12 and maximal oxygen consumption were moderately correlated (preintervention: 0.55, P = 0.003; postintervention: 0.48, P = 0.04) as one-time measures of fitness. Correlations of the tests as markets of change over time were poor and nonsignificant. Conclusion: In children with asthma, CT12 is a reasonable one-time estimate of fitness but a poor marker of fitness change over time

A reliability estimation tool for reducing infant mortality in Cubesat missions

For many years, traditional satellite design philosophy was dominated by highly reliable components, conservative designs and extensive performance testing at subsystem and integrated system levels to achieve long lifetimes in the harsh space environment. CubeSats attempted to choose a different philosophy, utilizing suitable state-of the art, commercial-off-the shelf products, yielding, if successful, an increased performance per mass figure of merit for those small vessels at potentially higher risk but lower cost. CubeSats seemed to promise universities and companies to be faster, better and cheaper - once more in history. Unfortunately, many CubeSat missions, especially university-built ones, never achieved a detectable functional state or failed shortly after the satellites were ejected from their deployer. Data based on our developed CubeSat Failure Database (CFD) and research carried out by others suggest, that a great percentage of those early failure cases could have been detected and avoided by more careful and adequate system-level functional testing on the ground. However, many university teams still fail to plan with adequate resources for system level functional testing or are confronted with hard deadlines, thus unable to complete appropriate integrated system testing on a sufficient level, and launching a satellite that never was adequately functional. Ongoing work on a novel reliability estimation tool using Bayesian methods is introduced to fill this gap and to provide meaningful data for all developers on the achievable reliability and required functional testing time of their CubeSats. Using test data and reliability goals for their actual mission, merging that data with statistical data from past missions and a database of subjective developer's beliefs, CubeSat developers should now be able to estimate their required functional testing time on subsystem and system level at an early project stage, as a function of the targeted reliability goal for their CubeSat. Alternatively, if the required resources (testing time, money, knowledge) are not available, CubeSat developers and program managers can still use the tool to now quantify a resulting realistic lower boundary for the expected system reliability of the mission, and decide, if their mission goals can be fulfilled or not with a certain probability. To evolve CubeSats into more reliable and accepted platforms for scientific payloads and commercial applications, it is utmost important to avoid or reduce the many infant mortality cases, where no or little useful data is produced by the satellite. To guide developers towards higher success rates without losing the spirit of using novel, state of the art technology in fast mission timelines, the reliability estimation tool should ensure higher reliability of CubeSat missions without drawing too much resources nor imposing too many burdens on the CubeSat teams.Space Systems Egineerin

Student Competence in Fluid and Electrolyte Management: The Impact of Various Teaching Methods

The goal of this study was to evaluate 1) the competency of junior medical students (M3s) in fluid and electrolyte management upon completion of their pediatric clerkship; 2) the frequency and perceived helpfulness of fluid and electrolyte management–based interactions with the following sources of education: a lecture, first-year residents (PL1s), senior residents (PL3s), and faculty; and 3) the relationship between points 1 and 2. Upon completion of the clerkship, M3 competency was evaluated by a quiz with multiple-choice questions and a clinical vignette concerning the intravenous fluid (IVF) management of a dehydrated child. Junior medical students completed a survey to identify the fluid and electrolyte management case-based practice frequency with PL1s, PL3s, and faculty, and the perceived helpfulness of the lecture, PL1s, PL3s, and faculty, rated on a 10-point Likert scale. One hundred eighty-seven M3s took the quiz and 180 completed surveys. The mean clinical vignette score was 7.0 (range, 0–12). Eighty-one percent of M3s wrote inadequate IVF orders for a dehydrated infant. The median-perceived helpfulness for each source was lecture, 9 points; PL1, 5 points; PL3, 4 points; and faculty, 3 points. In multivariate regression, only a higher perceived helpfulness rating for the lecture was significantly associated with higher clinical vignette scores ( r = 0.43; P < .001). When asked for ideas to improve fluid and electrolyte management education, 47% of M3s recommended more practice problems. Most M3s lacked adequate fluid and electrolyte management competency. Junior medical students rated the lecture the most helpful source of fluid and electrolyte management education. Improvements in fluid and electrolyte management education of M3s may result from providing practice problems with immediate feedback and formal training to increase the fluid and electrolyte management educational skills of PL1s, PL3s, and faculty

A novel faculty development tool for writing a letter of recommendation.

ObjectiveBased on a national survey of program directors we developed a letter of recommendation (LOR) scoring rubric (SR) to assess LORs submitted to a pediatric residency program. The objective was to use the SR to analyze: the consistency of LOR ratings across raters and LOR components that contributed to impression of the LOR and candidate.MethodsWe graded 30 LORs submitted to a pediatric residency program that were evenly distributed based on final rank by our program. The SR contained 3 sections (letter features, phrases, and applicant abilities) and 2 questions about the quality of the LOR (LORQ) and impression of the candidate (IC) after reading the LOR on a 5-point Likert scale. Inter-rater reliability was calculated with intraclass correlation coefficients (ICC(2,1)). Pearson (r) correlations and stepwise multivariate linear regression modeling predicted LORQ and IC. Mean scores of phrases, features, and applicant abilities were analyzed with ANOVA and Bonferroni correction.ResultsPhrases (ICC(2,1) = 0.82, pConclusionsThe SR was consistent across raters and correlates with impression of LORQ and IC. This rubric has potential as a faculty development tool for writing LORS