Multiscale Toxicology- Building the Next Generation Tools for Toxicology

A Cooperative Research and Development Agreement (CRADA) was established between Battelle Memorial Institute (BMI), Pacific Northwest National Laboratory (PNNL), Oak Ridge National Laboratory (ORNL), Brookhaven National Laboratory (BNL), Lawrence Livermore National Laboratory (LLNL) with the goal of combining the analytical and synthetic strengths of the National Laboratories with BMI�s expertise in basic and translational medical research to develop a collaborative pipeline and suite of high throughput and imaging technologies that could be used to provide a more comprehensive understanding of material and drug toxicology in humans. The Multi-Scale Toxicity Initiative (MSTI), consisting of the team members above, was established to coordinate cellular scale, high-throughput in vitro testing, computational modeling and whole animal in vivo toxicology studies between MSTI team members. Development of a common, well-characterized set of materials for testing was identified as a crucial need for the initiative. Two research tracks were established by BMI during the course of the CRADA. The first research track focused on the development of tools and techniques for understanding the toxicity of nanomaterials, specifically inorganic nanoparticles (NPs). ORNL�s work focused primarily on the synthesis, functionalization and characterization of a common set of NPs for dissemination to the participating laboratories. These particles were synthesized to retain the same surface characteristics and size, but to allow visualization using the variety of imaging technologies present across the team. Characterization included the quantitative analysis of physical and chemical properties of the materials as well as the preliminary assessment of NP toxicity using commercially available toxicity screens and emerging optical imaging strategies. Additional efforts examined the development of high-throughput microfluidic and imaging assays for measuring NP uptake, localization, and toxicity in vitro. The second research track within the MSTI CRADA focused on the development of ex vivo animal models for examining druginduced cardiotoxicity. ORNL's role in the second track was limited initially, but was later expanded to include the development of microfluidic platforms that might facilitate the translation of Cardiac 'Microwire' technologies developed at the University of Toronto into a functional platform for drug screening and predictive assessment of cardiotoxicity via highthroughput measurements of contractility. This work was coordinated by BMI with the Centre for the Commercialization of Regenerative Medicine (CCRM) and the University of Toronto (U Toronto). This partnership was expanded and culminated in the submission of proposal to Work for Others (WFO) agencies to explore the development of a broader set of microphysiological systems, a so call human-on-a-chip, that could be used for toxicity screening and the evaluation of bio-threat countermeasures

A Trauma Patient Advocate Is a Valuable Addition to the Multidisciplinary Trauma Team: A Process Improvement Project

Any member of the MDTT could request a consultation and assistance from the TPA on an individual basis after identifying specific patient needs on rounds and meeting the criteria of one or more of the following: patients with complex care issues such as poly trauma, having multiple consultants or service lines involved in the care of the patient, difficult family situations such as dealing with estranged family, difficult family communication due to work and travel schedules, need for assistance in decision-making for discharge planning such as choosing a skilled nursing facility, or need for improved communication and coordination of medical care such as coordinating schedules for combined service line cases. [...]we determined that the addition of the TPA to our busy, urban Level I trauma service was well received by the MDTT, subjectively improved team communication and efficiency, and was perceived to increase patient and family engagement and satisfaction with the trauma experience

Microstencils to generate defined, multi-species patterns of bacteria

Citation: Timm, C. M., Hansen, R. R., Doktycz, M. J., Retterer, S. T., & Pelletier, D. A. (2015). Microstencils to generate defined, multi-species patterns of bacteria. Biomicrofluidics, 9(6). doi:10.1063/1.4935938Microbial communities are complex heterogeneous systems that are influenced by physical and chemical interactions with their environment, host, and community members. Techniques that facilitate the quantitative evaluation of how microscale organization influences the morphogenesis of multispecies communities could provide valuable insights into the dynamic behavior and organization of natural communities, the design of synthetic environments for multispecies culture, and the engineering of artificial consortia. In this work, we demonstrate a method for patterning microbes into simple arrangements that allow the quantitative measurement of growth dynamics as a function of their proximity to one another. The method combines parylene-based liftoff techniques with microfluidic delivery to simultaneously pattern multiple bacterial species with high viability using low-cost, customizable methods. Quantitative measurements of bacterial growth for two competing isolates demonstrate that spatial coordination can play a critical role in multispecies growth and structure. © 2015 AIP Publishing LLC

Modes of Multiple Star Formation

This paper argues that star forming environments should be classified into finer divisions than the traditional isolated and clustered modes. Using the observed set of galactic open clusters and theoretical considerations regarding cluster formation, we estimate the fraction of star formation that takes place within clusters. We find that less than 10% of the stellar population originates from star forming regions destined to become open clusters, confirming earlier estimates. The smallest clusters included in the observational surveys (having at least N=100 members) roughly coincide with the smallest stellar systems that are expected to evolve as clusters in a dynamical sense. We show that stellar systems with too few members N < N_\star have dynamical relaxation times that are shorter than their formation times (1-2 Myr), where the critical number of stars N_\star \approx 100. Our results suggest that star formation can be characterized by (at least) three principal modes: I. isolated singles and binaries, II. groups (N<N_\star), and III. clusters (N>N_\star). Many -- if not most -- stars form through the intermediate mode in stellar groups with 10<N<100. Such groups evolve and disperse much more rapidly than open clusters; groups also have a low probability of containing massive stars and are unaffected by supernovae and intense ultraviolet radiation fields. Because of their short lifetimes and small stellar membership, groups have relatively little effect on the star formation process (on average) compared to larger open clusters.Comment: accepted to The Astrophysical Journa

Multi-Species Test of Ion Cyclotron Resonance Heating at High Altitudes

Observations of ion distributions and plasma waves obtained by the Dynamics Explorer 1 satellite in the high-altitude, nightside auroral zone are used to study ion energization for three ion species. A number of theoretical models have been proposed to account for the transverse heating of these ion populations. One of these, the ion cyclotron resonance heating (ICRH) mechanism, explains ion conic formation through ion cyclotron resonance with broadband electromagnetic wave turbulence in the vicinity of the characteristic ion cyclotron frequency. The cyclotron resonant heating of the ions by low-frequency electromagnetic waves is an important energy source for the transport of ions from the ionosphere to the magnetosphere. In this paper we test the applicability of the ICRH mechanism to three simultaneously heated and accelerated ion species by modelling the ion conic formation in terms of a resonant wave-particle interaction in which the ions extract energy from the portion of the broadband electromagnetic wave spectrum which includes the ion cyclotron frequency. Using a Monte Carlo technique we evaluate the ion heating produced by the electromagnetic turbulence at low frequencies and find that the wave amplitudes near the ion cyclotron frequencies are sufficient to explain the observed ion energies

Multi-Species Test of Ion Cyclotron Resonance Heating at High Altitudes

Observations of ion distributions and plasma waves obtained by the Dynamics Explorer 1 satellite in the high-altitude, nightside auroral zone are used to study ion energization for three ion species. A number of theoretical models have been proposed to account for the transverse heating of these ion populations. One of these, the ion cyclotron resonance heating (ICRH) mechanism, explains ion conic formation through ion cyclotron resonance with broadband electromagnetic wave turbulence in the vicinity of the characteristic ion cyclotron frequency. The cyclotron resonant heating of the ions by low- frequency electromagnetic waves is an important energy source for the transport of ions from the ionosphere to the magnetosphere. In this paper we test the applicability of the ICRH mechanism to three simultaneously heated and accelerated ion species by modelling the ion conic formation in terms of a resonant wave-particle interaction in which the ions extract energy from the portion of the broadband electromagnetic wave spectrum which includes the ion cyclotron frequency. Using a Monte Carlo technique we evaluate the ion heating produced by the electromagnetic turbulence at low frequencies and find that the wave amplitudes near the ion cyclotron frequencies are sufficient to explain the observed ion energies

Development of transparent microwell arrays for optical monitoring and dissection of microbial communities

Citation: Halsted, M., Wilmoth, J. L., Briggs, P. A., Hansen, R. R., Briggs, D. P., Timm, A. C., & Retterer, S. T. (2016). Development of transparent microwell arrays for optical monitoring and dissection of microbial communities. Journal of Vacuum Science & Technology B, 34(6), 5. doi:10.1116/1.4962739Microbial communities are incredibly complex systems that dramatically and ubiquitously influence our lives. They help to shape our climate and environment, impact agriculture, drive business, and have a tremendous bearing on healthcare and physical security. Spatial confinement, as well as local variations in physical and chemical properties, affects development and interactions within microbial communities that occupy critical niches in the environment. Recent work has demonstrated the use of silicon based microwell arrays, combined with parylene lift-off techniques, to perform both deterministic and stochastic assembly of microbial communities en masse, enabling the high-throughput screening of microbial communities for their response to growth in confined environments under different conditions. The implementation of a transparent microwell array platform can expand and improve the imaging modalities that can be used to characterize these assembled communities. Here, the fabrication and characterization of a next generation transparent microwell array is described. The transparent arrays, comprised of SU-8 patterned on a glass coverslip, retain the ability to use parylene lift-off by integrating a low temperature atomic layer deposition of silicon dioxide into the fabrication process. This silicon dioxide layer prevents adhesion of the parylene material to the patterned SU-8, facilitating dry lift-off, and maintaining the ability to easily assemble microbial communities within the microwells. These transparent microwell arrays can screen numerous community compositions using continuous, high resolution, imaging. The utility of the design was successfully demonstrated through the stochastic seeding and imaging of green fluorescent protein expressing Escherichia coli using both fluorescence and brightfield microscopies. (C) 2016 American Vacuum Society

Stochastic Assembly of Bacteria in Microwell Arrays Reveals the Importance of Confinement in Community Development

Citation: Hansen, R. H., Timm, A. C., Timm, C. M., Bible, A. N., Morrell-Falvey, J. L., Pelletier, D. A., . . . Retterer, S. T. (2016). Stochastic Assembly of Bacteria in Microwell Arrays Reveals the Importance of Confinement in Community Development. Plos One, 11(5), 18. doi:10.1371/journal.pone.0155080The structure and function of microbial communities is deeply influenced by the physical and chemical architecture of the local microenvironment and the abundance of its community members. The complexity of this natural parameter space has made characterization of the key drivers of community development difficult. In order to facilitate these characterizations, we have developed a microwell platform designed to screen microbial growth and interactions across a wide variety of physical and initial conditions. Assembly of microbial communities into microwells was achieved using a novel biofabrication method that exploits well feature sizes for control of innoculum levels. Wells with incrementally smaller size features created populations with increasingly larger variations in inoculum levels. This allowed for reproducible growth measurement in large (20 mu m diameter) wells, and screening for favorable growth conditions in small (5, 10 mu m diameter) wells. We demonstrate the utility of this approach for screening and discovery using 5 mu m wells to assemble P. aeruginosa colonies across a broad distribution of innoculum levels, and identify those conditions that promote the highest probability of survivial and growth under spatial confinement. Multi-member community assembly was also characterized to demonstrate the broad potential of this platform for studying the role of member abundance on microbial competition, mutualism and community succession

Observations and Simulations of Formation of Broad Plasma Depletions Through Merging Process

Broad plasma depletions in the equatorial ionosphere near dawn are region in which the plasma density is reduced by 1-3 orders of magnitude over thousands of kilometers in longitude. This phenomenon is observed repeatedly by the Communication/Navigation Outage Forecasting System (C/NOFS) satellite during deep solar minimum. The plasma flow inside the depletion region can be strongly upward. The possible causal mechanism for the formation of broad plasma depletions is that the broad depletions result from merging of multiple equatorial plasma bubbles. The purpose of this study is to demonstrate the feasibility of the merging mechanism with new observations and simulations. We present C/NOFS observations for two cases. A series of plasma bubbles is first detected by C/NOFS over a longitudinal range of 3300-3800 km around midnight. Each of the individual bubbles has a typical width of approx 100 km in longitude, and the upward ion drift velocity inside the bubbles is 200-400 m/s. The plasma bubbles rotate with the Earth to the dawn sector and become broad plasma depletions. The observations clearly show the evolution from multiple plasma bubbles to broad depletions. Large upward plasma flow occurs inside the depletion region over 3800 km in longitude and exists for approx 5 h. We also present the numerical simulations of bubble merging with the physics-based low-latitude ionospheric model. It is found that two separate plasma bubbles join together and form a single, wider bubble. The simulations show that the merging process of plasma bubbles can indeed occur in incompressible ionospheric plasma. The simulation results support the merging mechanism for the formation of broad plasma depletions

Curricular Evaluation Using Self-Efficacy Measurements

Self-efficacy measurements have been used in other health-related professions such as nursing and occupational therapy to assess proficiency in disciplinary areas but have not been used extensively in pharmacy education as a method of curricular evaluation. Self-efficacy is a measurement of an individual&apos;s confidence in his or her ability to perform a specific task to successful completion. The purpose of this study was to propose a methodology using self-efficacy measurements in curricular evaluation and assessment as well as to provide specific recommendations for potential uses in pharmacy education. The suggested methodology includes item generation, validation, administration, and correlation with behavior. A specific example is provided demonstrating the suggested methodology. Self-efficacy measurement could provide a potentially valuable methodologic framework for assessment and evaluation within pharmacy curricula. Self-efficacy measurements could be used in a wide range of applications