The Effect of Differing Degrees of Automation and Reliability on Simulated Luggage Screening Performance

The present work examined the effects of two types of decision support systems in a simulated luggage screening task: An input aid and an output aid. An input aid supports an operator’s information gathering. An output aid supports decision making and action selection. A Time-Accuracy Function (TAF) analysis was applied to isolate processing time from performance asymptote, which conventional performance measures such as sensitivity and response time do not distinguish one from the other. Sixty participants performed a luggage screening task unaided (manual condition), with the assistance of an input aid (spatial aid), and with the assistance of an output aid (decision aid) across different stimulus exposure durations of 250 ms, 500 ms, 1000 ms, 2000 ms, or 3000 ms. Participants were asked to judge the presence of a knife in each of the bags and either “stop” the bag or “pass” the bag. Reliability of the automated aids was 90% in Experiment 1 and 60% in Experiment 2. Experiment 1 showed that sensitivity increased with the assistance of both the input and the output aids as the stimulus exposure duration increased. The performance improvement was greater for the input aid than the output aid condition. Though processing times did not differ across the conditions, asymptotic performance level was higher when participants had the assistance of the input aid compared to the unaided condition. Experiment 2 and cross-experimental analysis demonstrated that the unreliable aids eliminated the benefit of the reliable aids. TAF analysis further showed that, although asymptotic performance can differ, processing times can remain constant regardless of DOA. The results imply that the input aid elevates asymptotic performance without influencing processing times, perhaps allowing operators to crosscheck their decisions within the restricted area of the search field identified by the aid. The present findings are inconsistent with the lumberjack hypothesis (Onnasch et al., 2013) and future research directions are provided

Investigating Intrinsic and Extrinsic Variables During Simulated Internet Search

Using an eye tracker we examined decision-making processes during an internet search task. Twenty experienced homebuyers and twenty-five undergraduates from Old Dominion University viewed homes on a simulated real estate website. Several of the homes included physical properties that had the potential to negatively impact individual perceptions. These negative externalities were either easy to change (Level 1) or impossible to change (Level 2). Eye movements were analyzed to examine the relationship between participants\u27 stated preferences [verbalized preferences], revealed preferences [actual decisions[, and experience. Dwell times, fixation durations/counts, and saccade counts/amplitudes were analyzed. Results revealed that experienced homebuyers demonstrated a more refined search pattern than novice searchers. Experienced homebuyers were also less impacted by negative externalities. Furthermore, stated preferences were discrepant from revealed preferences; although participants initially stated they liked/disliked a graphic, their eye movement patterns did not reflect this trend. These results have important implications for design of user-friendly web interfaces

Drought Stress Results in a Compartment-Specific Restructuring of the Rice Root-Associated Microbiomes.

Plant roots support complex microbial communities that can influence plant growth, nutrition, and health. While extensive characterizations of the composition and spatial compartmentalization of these communities have been performed in different plant species, there is relatively little known about the impact of abiotic stresses on the root microbiota. Here, we have used rice as a model to explore the responses of root microbiomes to drought stress. Using four distinct genotypes, grown in soils from three different fields, we tracked the drought-induced changes in microbial composition in the rhizosphere (the soil immediately surrounding the root), the endosphere (the root interior), and unplanted soils. Drought significantly altered the overall bacterial and fungal compositions of all three communities, with the endosphere and rhizosphere compartments showing the greatest divergence from well-watered controls. The overall response of the bacterial microbiota to drought stress was taxonomically consistent across soils and cultivars and was primarily driven by an enrichment of multiple Actinobacteria and Chloroflexi, as well as a depletion of several Acidobacteria and Deltaproteobacteria While there was some overlap in the changes observed in the rhizosphere and endosphere communities, several drought-responsive taxa were compartment specific, a pattern likely arising from preexisting compositional differences, as well as plant-mediated processes affecting individual compartments. These results reveal that drought stress, in addition to its well-characterized effects on plant physiology, also results in restructuring of root microbial communities and suggest the possibility that constituents of the altered plant microbiota might contribute to plant survival under extreme environmental conditions.IMPORTANCE With the likelihood that changes in global climate will adversely affect crop yields, the potential role of microbial communities in enhancing plant performance makes it important to elucidate the responses of plant microbiomes to environmental variation. By detailed characterization of the effect of drought stress on the root-associated microbiota of the crop plant rice, we show that the rhizosphere and endosphere communities undergo major compositional changes that involve shifts in the relative abundances of a taxonomically diverse set of bacteria in response to drought. These drought-responsive microbes, in particular those enriched under water deficit conditions, could potentially benefit the plant as they could contribute to tolerance to drought and other abiotic stresses, as well as provide protection from opportunistic infection by pathogenic microbes. The identification and future isolation of microbes that promote plant tolerance to drought could potentially be used to mitigate crop losses arising from adverse shifts in climate

The Role of MicroRNAs in Impaired Diabetic Wound Healing

Diabetes mellitus is a worldwide pandemic, affecting 29 million Americans, resulting in substantial morbidity and mortality, and accounting for an annual healthcare expenditure exceeding $176 billion in the US alone. This burden of disease is the result of a progressive disease associated with numerous complications and the development of chronic wounds, which remain the leading cause of hospital admissions and nontraumatic lower extremity amputations in diabetic patients. Despite clinical strategies aimed at prevention and early detection, patients with diabetes continue to remain at risk of developing chronic diabetic wounds due to poor patient compliance and progression of the diabetic phenotype. Development of the diabetic phenotype and wound healing impairment is associated with dysregulation of microRNAs that regulate inflammation, extracellular matrix composition, and angiogenesis; here we present evidence from the studies that demonstrate correction of microRNA dysregulation expedites wound healing and reverses the diabetic skin phenotype

On the joint distribution of the maximum and its position of the Airy2 process minus a parabola

The maximal point of the Airy2 process minus a parabola is believed to describe the scaling limit of the end-point of the directed polymer in a random medium, which was proved to be true for a few specific cases. Recently two different formulas for the joint distribution of the location and the height of this maximal point were obtained, one by Moreno Flores, Quastel and Remenik, and the other by Schehr. The first formula is given in terms of the Airy function and an associated operator, and the second formula is expressed in terms of the Lax pair equations of the Painleve II equation. We give a direct proof that these two formulas are the same.Comment: 15 pages, no figure, minor revision, to appear in J.Math.Phy

Transdisciplinary PhD programmes produce more high-impact publications and foster increased collaborations

Traditional doctoral programmes require students to gain in-depth knowledge in one subject area. Transdisciplinary programmes aim to foster synthesis across disciplines and focus on translating research findings into real-world solutions, helping students to develop a professional disciplinary identity that is enhanced by multidisciplinary methods and theories. Anna-Sigrid Keck, Stephanie Sloane, Janet M. Liechty, Barbara H. Fiese, and Sharon M. Donovan designed a structured doctoral programme focused on transdisciplinary research and compared students’ publication patterns to students in traditional programmes. While rates of productivity were broadly similar, citation rates were found to be higher for transdisciplinary students, as were indicators of collaboration such as co-authorship

Inhibition of stromal cell-derived factor-1α further impairs diabetic wound healing

ObjectiveImpaired diabetic wound healing is associated with abnormal stromal cell-derived factor (SDF)-1α production, decreased angiogenesis, and chronic inflammation. Lentiviral-mediated overexpression of SDF-1α can correct the impairments in angiogenesis and healing in diabetic wounds. We hypothesized that SDF-1α is a critical component of the normal wound-healing response and that inhibition of SDF-1α would further delay the wound-healing process.MethodsdB/Db diabetic mice and Db/+ nondiabetic mice were wounded with an 8-mm punch biopsy and the wounds treated with a lentiviral vector containing either the green fluorescent protein (GFP) or SDF-1α inhibitor transgene. The inhibitor transgene is a mutant form of SDF-1α that binds, but does not activate, the CXCR4 receptor. Computerized planimetry was used to measure wound size daily. Wounds were analyzed at 3 and 7 days by histology and for production of inflammatory markers using real-time polymerase chain reaction. The effect of the SDF-1α inhibitor on cellular migration was also assessed.ResultsInhibition of SDF-1α resulted in a significant decrease in the rate of diabetic wound healing, (3.8 vs 6.5 cm2/day in GFP-treated wounds; P = .04), and also impaired the early phase of nondiabetic wound healing. SDF-1α inhibition resulted in fewer small-caliber vessels, less granulation tissue formation, and increased proinflammatory gene expression of interleukin-6 and macrophage inflammatory protein-2 in the diabetic wounds.ConclusionsThe relative level of SDF-1α in the wound plays a key role in the wound-healing response. Alterations in the wound level of SDF-1α, as seen in diabetes or by SDF-1α inhibition, impair healing by decreasing cellular migration and angiogenesis, leading to increased production of inflammatory cytokines and inflammation. Inhibition of SDF-1α further impairs diabetic wound healing.Clinical RelevanceDiabetes results in a significant impairment in wound healing, leading to significant morbidity and health care expenditures. The pathophysiology that underlies this process is multifactorial, including abnormal growth factor production, cellular migration, and cellular function. Stromal cell-derived factor (SDF)-1α is a key chemokine involved in the wound-healing process and is involved in cellular recruitment and angiogenesis. SDF-1α is decreased in diabetic individuals. This study showed that inhibition of SDF-1α results in an even more dramatic delay in the diabetic wound-healing process and even results in a delay in the early phases of wound healing in normal mice, further supporting its role in wound healing. Inhibition of this chemokine promotes greater inflammatory cytokine production, inflammatory cell migration, and less vasculogenesis after dermal wounding. This study identifies SDF-1α as an essential component of normal wound healing and provides a potential therapeutic target to improve the diabetic wound-healing impairment

Fostering reciprocity in global health partnerships through a structured, hands-on experience for visiting postgraduate medical trainees

BACKGROUND: Global health programs that allow international experiences for US learners should also enable reciprocal learning experiences for international learners, particularly if that is a need identified by the partner institution. METHODS: A partnership between Indiana University and Moi University, Kenya, has successfully hosted 41 visiting Kenyan internal medicine and pediatrics registrars at Indiana University since 2006. The program's logistics, curriculum, and evaluation are described. RESULTS: The registrars rotated through nephrology, cardiology, hematology and oncology, infectious diseases, and intensive care, as well as related ambulatory experiences, functioning on a level comparable to fourth-year medical students. They showed significant improvement in pretest and posttest scores on a standardized National Board of Medical Examiners examination (P  =  .048). International learners experienced culture shock, yet they felt the Indiana University elective was helpful and would recommend it to future participants. CONCLUSIONS: Global health programs can reciprocate the benefits derived for US students and residents by offering learning experiences to international learners if that is an expressed need from the international partner. Barriers to those experiences can be overcome, and the hands-on, elective experience has the potential to positively affect the knowledge and attitudes of participants as well as the home nation

DSMC Shock Simulation of Saturn Entry Probe Conditions

This work describes the direct simulation Monte Carlo (DSMC) investigation of Saturn entry probe scenarios and the influence of non-equilibrium phenomena on Saturn entry conditions. The DSMC simulations coincide with rarefied hypersonic shock tube experiments of a hydrogen-helium mixture performed in the Electric Arc Shock Tube (EAST) at NASA Ames Research Center. To directly compare to the experimental results, the DSMC simulations are post-processed through the NEQAIR line-by-line radiation code. Improved collision cross-sections, inelastic collision parameters, and reaction rates are determined for a high temperature DSMC simulation of a 7-species H2-He mixture and an electronic excitation model is implemented in the DSMC code. Simulation results for 27.8 and 27.4 kms shock waves are obtained at 0.2 and 0.1 Torr respectively and compared to measured spectra in the VUV, UV, visible, and IR ranges. These results confirm the persistence of non-equilibrium for several centimeters behind the shock and the diffusion of atomic hydrogen upstream of the shock wave. Although the magnitude of the radiance did not match experiments and an ionization inductance period was not observed in the simulations, the discrepancies indicated where improvements are needed in the DSMC and NEQAIR models