Developing an engineering leadership identity.

This article posits the importance of viewing leadership development in engineering through an identity lens. The model presented shows the development of an engineering leadership identity at the intersection of engineering and leadership identities and explores that development through the findings from two national surveys with additional support from a deeper investigation using student focus groups.

The influence of inferred traffic safety culture on traffic safety performance in U.S. States (1994-2014).

INTRODUCTION: Traffic safety performance (crash fatalities per billion vehicle miles traveled) is influenced by many factors related to the physical and social environment. The traffic safety culture in the local environment can influence behaviors that influence the risk of a fatal crash. However, if traffic safety culture is defined as "shared beliefs," it is not possible to directly observe the effect of culture on traffic safety performance. METHOD: This study replicated the method proposed by Page (2001) to infer the effect of traffic safety culture on traffic safety performance for U.S. states between 1994 and 2014. This method infers the influence of traffic safety culture from the error between actual and predicted performance based on observable variables that measure the physical and social environment as well as behavioral hazards. RESULTS: The results suggest that a positive traffic safety culture can have a protective effect by producing a lower-than-expected fatality rate. Conversely, a negative traffic safety culture can have an exacerbating effect by producing a larger-than-expected fatality rate. CONCLUSION: The derived metric for estimating traffic safety culture had strong concurrent validity by correlating with the ranking of states based only on total crash fatality rate. PRACTICAL IMPLICATIONS: Consistent with Page (2001), the analysis also identified common risk factors across states including per capita alcohol consumption and unemployment rate.

Primary human chondrocytes respond to compression with phosphoproteomic signatures that include microtubule activation.

Chondrocytes are responsible for maintaining the cartilage that helps joints bear load and move smoothly. These cells typically respond to physiological compression with pathways consistent with matrix synthesis, and chondrocyte mechanotransduction is essential for homeostasis. In osteoarthritis (OA), chondrocyte mechanotransduction appears to be dysregulated, yet the mechanisms remain poorly understood. The objective of this study is to document the phosphoproteomic responses of primary osteoarthritic chondrocytes to physiological sinusoidal compression. We show that OA chondrocytes respond to physiological compression by first activating proteins consistent with cytoskeletal remodeling and decreased transcription, and then later activating proteins for transcription. These results show that several microtubule-related proteins respond to compression. Our results demonstrate that compression is a relevant physiological stimulus for osteoarthritic chondrocytes. Future analyses may build on these results to find differences in compression-induced phosphoproteins between normal and OA cells that lead to druggable targets to restore homeostasis to diseased joints.

Charge Transition of Oxygen Vacancies during Resistive Switching in Oxide-Based RRAM.

Resistive random-access memory (RRAM) devices have attracted broad interest as promising building blocks for high-density nonvolatile memory and neuromorphic computing applications. Atomic level thermodynamic and kinetic descriptions of resistive switching (RS) processes are essential for continued device design and optimization but are relatively lacking for oxide-based RRAMs. It is generally accepted that RS occurs due to the redistribution of charged oxygen vacancies driven by an external electric field. However, this assumption contradicts the experimentally observed stable filaments, where the high vacancy concentration should lead to a strong Coulomb repulsion and filament instability. In this work, through predictive atomistic calculations in combination with experimental measurements, we attempt to understand the interactions between oxygen vacancies and the microscopic processes that are required for stable RS in a Ta2O5-based RRAM. We propose a model based on a series of charge transition processes that explains the drift and aggregation of vacancies during RS. The model was validated by experimental measurements where illuminated devices exhibit accelerated RS behaviors during SET and RESET. The activation energies of ion migration and charge transition were further experimentally determined through a transient current measurement, consistent with the modeling results. Our results help provide comprehensive understanding on the internal dynamics of RS and will benefit device optimization and applications.

Developing a theoretical foundation to change road user behavior and improve traffic safety: Driving under the influence of cannabis (DUIC).

OBJECTIVES: This study explored a theoretical model to assess the influence of culture on willingness and intention to drive under the influence of cannabis (DUIC). This model is expected to guide the design of strategies to change future DUIC behavior in road users. METHODS: This study used a survey methodology to obtain a nationally representative sample (n = 941) from the AmeriSpeak Panel. Survey items were designed to measure aspects of a proposed definition of traffic safety culture and a predictive model of its relationship to DUIC. RESULTS: Although the percentage of reported past DUIC behaviors was relatively low (8.5%), this behavior is still a significant public health issue-especially for younger drivers (18-29 years), who reported more DUIC than expected. Findings suggest that specific cultural components (attitudes, norms) reliably predict past DUIC behavior, general DUIC willingness, and future DUIC intention. Most DUIC behavior appears to be deliberate, related significantly to willingness and intention. Intention and willingness both appear to fully moderate the relationship between traffic safety culture and DUIC behavior. CONCLUSIONS: This study explored a theoretical model to understand road user behavior involving drug (cannabis)-impaired driving as a significant risk factor for traffic safety. By understanding the cultural factors that increase DUIC behavior, we can create strategies to transform this culture and sustain safer road user behavior.

Encapsulation of chondrocytes in high-stiffness agarose microenvironments for in vitro modeling of osteoarthritis mechanotransduction.

In articular cartilage, chondrocytes reside within a gel-like pericellular matrix (PCM). This matrix provides a mechanical link through which joint loads are transmitted to chondrocytes. The stiffness of the PCM decreases in the most common degenerative joint disease, osteoarthritis. To develop a system for modeling the stiffness of both the healthy and osteoarthritic PCM, we determined the concentration-stiffness relationships for agarose. We extended these results to encapsulate chondrocytes in agarose of physiological stiffness. Finally, we assessed the relevance of stiffness for chondrocyte mechanotransduction by examining the biological response to mechanical loading for cells encapsulated in low- and high-stiffness gels. We achieved agarose equilibrium stiffness values as large as 51.3 kPa. At 4.0% agarose, we found equilibrium moduli of 34.3 ± 1.65 kPa, and at 4.5% agarose, we found equilibrium moduli of 35.7 ± 0.95 kPa. Cyclical tests found complex moduli of ~100-300 kPa. Viability was >96% for all studies. We observed distinct metabolomic responses in >500 functional small molecules describing changes in cell physiology, between primary human chondrocytes encapsulated in 2.0 and 4.5% agarose indicating that the gel stiffness affects cellular mechanotransduction. These data demonstrate both the feasibility of modeling the chondrocyte pericellular matrix stiffness and the importance of the physiological pericellular stiffness for understanding chondrocyte mechanotransduction.

Automated vs manual triage for bioterrorist disaster: a blinded crossover feasibility study comparing personal digital assistant to paper-based triage.

INTRODUCTION: This article reports results of a National Institutes of Health/National Library of Medicine Small Business Innovation Research-funded research grant comparing paper-based and automated Palm handheld computer disaster triage documentation. OBJECTIVES: The aim of this study was to test the feasibility of automated handheld computer triage and compare it to handwritten triage. METHODS: A paired t test was used in an intraindividual, blinded, crossover study to compare the 2 methods of disaster triage by 2 objective measures--time and accuracy. A total of 57 experienced, licensed first responders participated. Results are from analysis of 8 disaster scenarios with a total of 400 patients triaged using the 2 methods of documentation, crossed over, blinded, and paired per participant. RESULTS: The study demonstrated the feasibility of using TriageDoc, a Palm personal digital assistant (PDA ) program, as a viable alternative to current manual disaster triage. Furthermore, the PDA program gave advantage to bioterrorist agent identification. CONCLUSIONS: The feasibility of an automated Palm (Palm, Inc., Sunnyvale, CA) PDA triage program was demonstrated in this study. Study limitations, by the number of participants and the fact it is feasibility research, are acknowledged. Nevertheless, the research demonstrated TriageDoc was as accurate or more accurate as the manual method of triage with a tendency to require less time. Also there was no statistically significant difference between research sites with respect to accuracy or time to completion when the TriageDoc system was used. The program provided consistency and had flexibility in adapting to the various differences in triage methods at different locations. Hence, PDA programs such as TriageDoc may have potential advantages over handwritten documentation for disaster triage.

Concentrations of plutonium and americium in plankton from the western Mediterranean Sea.

Understanding the transfer of radionuclides through the food chain leading to man and in particular, the uptake of transuranic nuclides by plankton, is basic to assess the potential radiological risk of the consumption of marine products by man. The main sources of transuranic elements in the Mediterranean Sea in the past were global fallout and the Palomares accident, although at present smaller amounts are released from nuclear establishments in the northwestern region. Plankton from the western Mediterranean Sea was collected and analyzed for plutonium and americium in order to study their biological uptake. The microplankton fractions accounted for approximately 50% of the total plutonium contents in particulate form. At Garrucha (Palomares area), microplankton showed much higher 239,240 Pu activity, indicating the contamination with plutonium from the bottom sediments. Concentration factors were within the range of the values recommended by the International Atomic Energy Agency. Continental shelf mesoplankton was observed to efficiently concentrate transuranics. In open seawaters, concentrations were much lower. We speculate that sediments might play a role in the transfer of transuranics to mesoplankton in coastal waters, although we cannot discard that the difference in species composition may also play a role. In Palomares, both 239,240 Pu and 241Am showed activities five times higher than the mean values observed in continental shelf mesoplankton. As the plutonium isotopic ratios in the contaminated sample were similar to those found in material related to the accident, the contamination was attributed to bomb debris from the Palomares accident. Concentration factors in mesoplankton were also in relatively good agreement with the ranges recommended by IAEA. In the Palomares station the highest concentration factor was observed in the sample that showed predominance of the dynoflagellate Ceratium spp. Mean values of the enrichment factors showed, on average, discrimination rather than enrichment in the primary producer trophic chain.