Showing papers by "Boise State University published in 2009"

The Influences of Cell Type and ZnO Nanoparticle Size on Immune Cell Cytotoxicity and Cytokine Induction

Abstract: Nanotechnology represents a new and enabling platform that promises to provide a range of innovative technologies for biological applications. ZnO nanoparticles of controlled size were synthesized, and their cytotoxicity toward different human immune cells evaluated. A differential cytotoxic response between human immune cell subsets was observed, with lymphocytes being the most resistant and monocytes being the most susceptible to ZnO nanoparticle-induced toxicity. Significant differences were also observed between previously activated memory lymphocytes and naive lymphocytes, indicating a relationship between cell-cycle potential and nanoparticle susceptibility. Mechanisms of toxicity involve the generation of reactive oxygen species, with monocytes displaying the highest levels, and the degree of cytotoxicity dependent on the extent of nanoparticle interactions with cellular membranes. An inverse relationship between nanoparticle size and cytotoxicity, as well as nanoparticle size and reactive oxygen species production was observed. In addition, ZnO nanoparticles induce the production of the proinflammatory cytokines, IFN-γ, TNF-α, and IL-12, at concentrations below those causing appreciable cell death. Collectively, these results underscore the need for careful evaluation of ZnO nanoparticle effects across a spectrum of relevant cell types when considering their use for potential new nanotechnology-based biological applications.

Giant magnetic-field-induced strains in polycrystalline Ni–Mn–Ga foams

Abstract: The magnetic shape-memory alloy Ni-Mn-Ga shows, in monocrystalline form, a reversible magnetic-field-induced strain (MFIS) up to 10%. This strain, which is produced by twin boundaries moving solely by internal stresses generated by magnetic anisotropy energy, can be used in actuators, sensors and energy-harvesting devices. Compared with monocrystalline Ni-Mn-Ga, fine-grained Ni-Mn-Ga is much easier to process but shows near-zero MFIS because twin boundary motion is inhibited by constraints imposed by grain boundaries. Recently, we showed that partial removal of these constraints, by introducing pores with sizes similar to grains, resulted in MFIS values of 0.12% in polycrystalline Ni-Mn-Ga foams, close to those of the best commercial magnetostrictive materials. Here, we demonstrate that introducing pores smaller than the grain size further reduces constraints and markedly increases MFIS to 2.0-8.7%. These strains, which remain stable over >200,000 cycles, are much larger than those of any polycrystalline, active material.

Fundamental Frequency Switching Strategies of a Seven-Level Hybrid Cascaded H-Bridge Multilevel Inverter

Abstract: This paper presents a cascaded H-bridge multilevel inverter that can be implemented using only a single dc power source and capacitors. Standard cascaded multilevel inverters require n dc sources for 2n + 1 levels. Without requiring transformers, the scheme proposed here allows the use of a single dc power source (e.g., a battery or a fuel cell stack) with the remaining n-1 dc sources being capacitors, which is referred to as hybrid cascaded H-bridge multilevel inverter (HCMLI) in this paper. It is shown that the inverter can simultaneously maintain the dc voltage level of the capacitors and choose a fundamental frequency switching pattern to produce a nearly sinusoidal output. HCMLI using only a single dc source for each phase is promising for high-power motor drive applications as it significantly decreases the number of required dc power supplies, provides high-quality output power due to its high number of output levels, and results in high conversion efficiency and low thermal stress as it uses a fundamental frequency switching scheme. This paper mainly discusses control of seven-level HCMLI with fundamental frequency switching control and how its modulation index range can be extended using triplen harmonic compensation.

DC–AC Cascaded H-Bridge Multilevel Boost Inverter With No Inductors for Electric/Hybrid Electric Vehicle Applications

Abstract: This paper presents a cascaded H-bridge multilevel boost inverter for electric vehicle (EV) and hybrid EV (HEV) applications implemented without the use of inductors. Currently available power inverter systems for HEVs use a dc-dc boost converter to boost the battery voltage for a traditional three-phase inverter. The present HEV traction drive inverters have low power density, are expensive, and have low efficiency because they need a bulky inductor. A cascaded H-bridge multilevel boost inverter design for EV and HEV applications implemented without the use of inductors is proposed in this paper. Traditionally, each H-bridge needs a dc power supply. The proposed design uses a standard three-leg inverter (one leg for each phase) and an H-bridge in series with each inverter leg which uses a capacitor as the dc power source. A fundamental switching scheme is used to do modulation control and to produce a five-level phase voltage. Experiments show that the proposed dc-ac cascaded H-bridge multilevel boost inverter can output a boosted ac voltage without the use of inductors.

Controls on the temporal and spatial variability of soil moisture in a mountainous landscape: the signature of snow and complex terrain

Abstract: . The controls on the spatial distribution of soil moisture include static and dynamic variables. The superposition of static and dynamic controls can lead to different soil moisture patterns for a given catchment during wetting, draining, and drying periods. These relationships can be further complicated in snow-dominated mountain regions where soil water input by precipitation is largely dictated by the spatial variability of snow accumulation and melt. In this study, we assess controls on spatial and temporal soil moisture variability in a small (0.02 km2), snow-dominated, semi-arid catchment by evaluating spatial correlations between soil moisture and site characteristics through different hydrologic seasons. We assess the relative importance of snow with respect to other catchment properties on the spatial variability of soil moisture and track the temporal persistence of those controls. Spatial distribution of snow, distance from divide, soil texture, and soil depth exerted significant control on the spatial variability of moisture content throughout most of the hydrologic year. These relationships were strongest during the wettest period and degraded during the dry period. As the catchment cycled through wet and dry periods, the relative spatial variability of soil moisture tended to remain unchanged. We suggest that the static properties in complex terrain (slope, aspect, soils) impose first order controls on the spatial variability of snow and resulting soil moisture patterns, and that the interaction of dynamic (timing of water input) and static influences propagate that relative constant spatial variability through most of the hydrologic year. The results demonstrate that snow exerts significant influence on how water is retained within mid-elevation semi-arid catchments and suggest that reductions in annual snowpacks associated with changing climate regimes may strongly influence spatial and temporal soil moisture patterns and catchment physical and biological processes.

Differential Effects of a Tier Two Behavior Intervention Based on Function of Problem Behavior.

Abstract: The purpose of this study was to investigate the effectiveness of a tier two daily behavior card intervention and differential effects based on function of problem behavior. The participants were 36 elementary school students nominated for additional intervention beyond universal School-Wide Positive Behavior Support. Measures included standardized behavior rating scales and rate of office discipline referrals before and after 8 weeks of intervention. A multivariate analysis of variance was used, and results showed statistically significant differences in response to intervention based on teacher-identified function of problem behavior. Results are discussed in terms of considering function of behavior in selecting tier two interventions and implementing a three-tier response to intervention model.

CUDA Implementation of a Navier-Stokes Solver on Multi-GPU Desktop Platforms for Incompressible Flows

Abstract: Graphics processor units (GPU) that are traditionally designed for graphics rendering have emerged as massively-parallel "co-processors" to the central processing unit (CPU). Small-footprint desktop supercomputers with hundreds of cores that can deliver teraflops peak performance at the price of conventional workstations have been realized. A computational fluid dynamics (CFD) simulation capability with rapid computational turnaround time has the potential to transform engineer ing analysis and design optimization procedures. We describe the implementation of a Navier-Stokes solver for incompressible fluid flow using desktop platforms equipped with multi-GPUs. Specifically, NVIDIA’s Compute Unified Device Architecture (CUDA) programming model is used to implement the discretized form of the governing equations. The pr ojection algorithm to solve the incompressible fluid flow equations is divided into distinct CUDA kernels, and a unique implementation that exploits the memory hierarchy of the CUDA programming model is suggested. Using a quad-GPU platform, we observe two orders of magnitude speedup relative to a serial CPU implementation. Our result s demonstrate that multi-GPU desktops can serve as a cost-effective small-footprint paral lel computing platform to accelerate CFD simulations substantially.

Lead bullet fragments in venison from rifle-killed deer: potential for human dietary exposure.

Abstract: Human consumers of wildlife killed with lead ammunition may be exposed to health risks associated with lead ingestion. This hypothesis is based on published studies showing elevated blood lead concentrations in subsistence hunter populations, retention of ammunition residues in the tissues of hunter-killed animals, and systemic, cognitive, and behavioral disorders associated with human lead body burdens once considered safe. Our objective was to determine the incidence and bioavailability of lead bullet fragments in hunter-killed venison, a widely-eaten food among hunters and their families. We radiographed 30 eviscerated carcasses of White-tailed Deer (Odocoileus virginianus) shot by hunters with standard lead-core, copper-jacketed bullets under normal hunting conditions. All carcasses showed metal fragments (geometric mean = 136 fragments, range = 15–409) and widespread fragment dispersion. We took each carcass to a separate meat processor and fluoroscopically scanned the resulting meat packages; fluoroscopy revealed metal fragments in the ground meat packages of 24 (80%) of the 30 deer; 32% of 234 ground meat packages contained at least one fragment. Fragments were identified as lead by ICP in 93% of 27 samples. Isotope ratios of lead in meat matched the ratios of bullets, and differed from background lead in bone. We fed fragment-containing venison to four pigs to test bioavailability; four controls received venison without fragments from the same deer. Mean blood lead concentrations in pigs peaked at 2.29 µg/dL (maximum 3.8 µg/dL) 2 days following ingestion of fragment-containing venison, significantly higher than the 0.63 µg/dL averaged by controls. We conclude that people risk exposure to bioavailable lead from bullet fragments when they eat venison from deer killed with standard lead-based rifle bullets and processed under normal procedures. At risk in the U.S. are some ten million hunters, their families, and low-income beneficiaries of venison donations.

Modeling soil depth from topographic and land cover attributes

Abstract: [1] Soil depth is an important input parameter in hydrological and ecological modeling. Presently, the soil depth data available in national soil databases (STATSGO and SSURGO) from the Natural Resources Conservation Service are provided as averages within generalized land units (map units). Spatial uncertainty within these units limits their applicability for distributed modeling in complex terrain. This work reports statistical models for prediction of soil depth in a semiarid mountainous watershed that are based upon the relationship between soil depth and topographic and land cover attributes. Soil depth was surveyed by driving a rod into the ground until refusal at locations selected to represent the topographic and land cover variation in the Dry Creek Experimental Watershed near Boise, Idaho. The soil depth survey consisted of a model calibration set, measured at 819 locations over 8 subwatersheds representing topographic and land cover variability and a model testing set, measured at 130 more broadly distributed locations in the watershed. Many model input variables were developed for regression to the field data. Topographic attributes were derived from a digital elevation model. Land cover attributes were derived from Landsat remote sensing images and high-resolution aerial photographs. Generalized additive and random forests models were developed to predict soil depth over the watershed. They were able to explain about 50% of the soil depth spatial variation, which is an important improvement over the soil depth extracted from the SSURGO national soil database.

Seismic Wave Attenuation in Carbonates

Abstract: [1] The effect of pore fluids on seismic wave attenuation in carbonate rocks is important for interpreting remote sensing observations of carbonate reservoirs undergoing enhanced oil recovery. Here we measure the elastic moduli and attenuation in the laboratory for five carbonate samples with 20% to 30% porosity and permeability between 0.03 and 58.1 mdarcy. Contrary to most observations in sandstones, bulk compressibility losses dominate over shear wave losses for dry samples and samples fully saturated with either liquid butane or brine. This observation holds for four out of five samples at seismic (10–1000 Hz) and ultrasonic frequencies (0.8 MHz) and reservoir pressures. Attenuation modeled from the modulus data using Cole-Cole relations agrees in that the bulk losses are greater than the shear losses. On average, attenuation increases by 250% when brine substitutes a light hydrocarbon in these carbonate rocks. For some of our samples, attenuation is frequency-dependent, but in the typical exploration frequency range (10–100 Hz), attenuation is practically constant for the measured samples.

How Can We Improve the Accuracy of Screening Instruments

Abstract: Screening for early reading problems is a critical step in early intervention and prevention of later reading difficulties. Evaluative frameworks for determining the utility of a screening process are presented in the literature but have not been applied to many screening measures currently in use in numerous schools across the nation. In this study, the accuracy of several Dynamic Indicators of Basic Early Literacy Skills (DIBELS) subtests in predicting which students were at risk for reading failure in first grade was examined in a sample of 12,055 students in Florida. Findings indicate that the DIBELS Nonsense Word Fluency, Initial Sound Fluency, and Phoneme Segmentation Fluency measures show poor diagnostic utility in predicting end of Grade 1 reading performance. DIBELS Oral Reading Fluency in fall of Grade 1 had higher classification accuracy than other DIBELS measures, but when compared to the classification accuracy obtained by assuming that no student had a disability, suggests the need to reevaluate the use of classification accuracy as a way to evaluate screening measures without discussion of base rates. Additionally, when cut scores on the screening tools were set to capture 90 percent of all students at risk for reading problems, a high number of false positives were identified. Finally, different cut scores were needed for different subgroups, such as English Language Learners. Implications for research and practice are discussed.

A radial basis function method for the shallow water equations on a sphere

Abstract: The paper derives the first known numerical shallow water model on the sphere using radial basis function (RBF) spatial discretization, a novel numerical methodology that does not require any grid or mesh. In order to perform a study with regard to its spatial and temporal errors, two nonlinear test cases with known analytical solutions are considered. The first is a global steady-state flow with a compactly supported velocity field, while the second is an unsteady flow where features in the flow must be kept intact without dispersion. This behaviour is achieved by introducing forcing terms in the shallow water equations. Error and time stability studies are performed, both as the number of nodes are uniformly increased and the shape parameter of the RBF is varied, especially in the flat basis function limit. Results show that the RBF method is spectral, giving exceptionally high accuracy for low number of basis functions while being able to take unusually large time steps. In order to put it in the context of other commonly used global spectral methods on a sphere, comparisons are given with respect to spherical harmonics, double Fourier series and spectral element methods.

Concurrent Validity of Office Discipline Referrals and Cut Points Used in Schoolwide Positive Behavior Support

Abstract: Office discipline referrals (ODRs) are commonly used by school teams implementing schoolwide positive behavior support to indicate individual student need for additional behavior support. However, little is known about the technical adequacy of ODRs when used in this manner. In this study, the authors assessed (a) the concurrent validity of number of ODRs received with a contemporary standardized behavior rating scale (the BASC-2 Teacher Report Form) and (b) the validity of common cut points to determine level of support needed (i.e., 0 to 1, 2 to 5, and 6 or more ODRs). Results indicated strong correlations between ODRs and rating of externalizing behavior and statistically and clinically significant differences in behavior ratings based on existing ODR cut points, but there was no significant relation between ODRs and ratings of internalizing problems. Results are discussed in terms of recommended use of ODRs as a screening measure to indicate level of behavior support required.

Ferroelectricity in ultrathin BaTiO3 films: probing the size effect by ultraviolet Raman spectroscopy.

Abstract: We demonstrate the dramatic effect of film thickness on the ferroelectric phase transition temperature Tc in strained BaTiO3 films grown on SrTiO3 substrates. Using variable-temperature ultraviolet Raman spectroscopy enables measuring Tc in films as thin as 1.6 nm, and a film thickness variation from 1.6 to 10 nm leads to Tc tuning from 70 to about 925 K. Raman data are consistent with synchrotron x-ray scattering results, which indicate the presence of 180 degrees domains below Tc, and thermodynamic phase-field model calculations of Tc as a function of thickness.

Fitness of children with standard-risk acute lymphoblastic leukemia during maintenance therapy: response to a home-based exercise and nutrition program.

Abstract: BackgroundAltered nutrient intake and decreased exercise in response to cancer therapies and their side effects, particularly corticosteroids, may be key factors in the increased body weight and differences in physical fitness reported in survivors of childhood acute lymphoblastic leukemia (ALL).Pur

Fluorescent Dye Encapsulated ZnO Particles with Cell-Specific Toxicity for Potential Use in Biomedical Applications

Abstract: Fluorescein isothiocyanate (FITC)-encapsulated SiO(2) core-shell particles with a nanoscale ZnO finishing layer have been synthesized for the first time as multifunctional "smart" nanostructures. Detailed characterization studies confirmed the formation of an outer ZnO layer on the SiO(2)-FITC core. These approximately 200 nm sized particles showed promise toward cell imaging and cellular uptake studies using the bacterium Escherichia coli and Jurkat cancer cells, respectively. The FITC encapsulated ZnO particles demonstrated excellent selectivity in preferentially killing Jurkat cancer cells with minimal toxicity to normal primary immune cells (18% and 75% viability remaining, respectively, after exposure to 60 microg/ml) and inhibited the growth of both gram-positive and gram-negative bacteria at concentrations > or =250-500 microg/ml (for Staphylococcus aureus and Escherichia coli, respectively). These results indicate that the novel FITC encapsulated multifunctional particles with nanoscale ZnO surface layer can be used as smart nanostructures for particle tracking, cell imaging, antibacterial treatments and cancer therapy.

Multiwavelength monitoring of the enigmatic narrow-line seyfert 1 pmn j0948+0022 in 2009 march-july

Abstract: Following the recent discovery of gamma rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z=0.5846), we started a multiwavelength campaign from radio to gamma rays, which was carried out between the end of March and the beginning of July 2009. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to gamma-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the gamma-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day-scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

A potential-based inversion of unconfined steady-state hydraulic tomography.

Abstract: The importance of estimating spatially variable aquifer parameters such as transmissivity is widely recognized for studies in resource evaluation and contaminant transport. A useful approach for mapping such parameters is inverse modeling of data from series of pumping tests, that is, via hydraulic tomography. This inversion of field hydraulic tomographic data requires development of numerical forward models that can accurately represent test conditions while maintaining computational efficiency. One issue this presents is specification of boundary and initial conditions, whose location, type, and value may be poorly constrained. To circumvent this issue when modeling unconfined steady-state pumping tests, we present a strategy that analyzes field data using a potential difference method and that uses dipole pumping tests as the aquifer stimulation. By using our potential difference approach, which is similar to modeling drawdown in confined settings, we remove the need for specifying poorly known boundary condition values and natural source/sink terms within the problem domain. Dipole pumping tests are complementary to this strategy in that they can be more realistically modeled than single-well tests due to their conservative nature, quick achievement of steady state, and the insensitivity of near-field response to far-field boundary conditions. After developing the mathematical theory, our approach is first validated through a synthetic example. We then apply our method to the inversion of data from a field campaign at the Boise Hydrogeophysical Research Site. Results from inversion of nine pumping tests show expected geologic features, and uncertainty bounds indicate that hydraulic conductivity is well constrained within the central site area.

Simulated Soil Water Storage Effects on Streamflow Generation in a Mountainous Snowmelt Environment, Idaho, USA

Abstract: Although soil processes affect the timing and amount of streamflow generated from snowmelt, they are often overlooked in estimations of snowmelt-generated streamflow in the western USA. The use of a soil water balance modelling approach to incorporate the effects of soil processes, in particular soil water storage, on the timing and amount of snowmelt generated streamflow, was investigated. The study was conducted in the Reynolds Mountain East (RME) watershed, a 38 ha, snowmelt-dominated watershed in southwest Idaho. Snowmelt or rainfall inputs to the soil were determined using a well established snow accumulation and melt model (Isnobal). The soil water balance model was first evaluated at a point scale, using periodic soil water content measurements made over two years at 14 sites. In general, the simulated soil water profiles were in agreement with measurements (P 0·85), y-intercept values near 0, slopes near 1 and low average differences between measured and modelled values. In addition, observed soil water dynamics were generally consistent with critical model assumptions. Spatially distributed simulations over the watershed for the same two years indicate that streamflow initiation and cessation are closely linked to the overall watershed soil water storage capacity, which acts as a threshold. When soil water storage was below the threshold, streamflow was insensitive to snowmelt inputs, but once the threshold was crossed, the streamflow response was very rapid. At these times there was a relatively high degree of spatial continuity of satiated soils within the watershed. Incorporation of soil water storage effects may improve estimation of the timing and amount of streamflow generated from mountainous watersheds dominated by snowmelt. Copyright © 2008 John Wiley & Sons, Ltd.

Complex Dielectric Permittivity Measurements from Ground-Penetrating Radar Data to Estimate Snow Liquid Water Content in the Pendular Regime

Abstract: [1] Monitoring the snow water equivalent (SWE) is critical to effective management of water resources in many parts of the world that depend on the mountain snowpack for water storage. There are currently no methods to remotely sense SWE with accuracy over large lateral distances in the steep and often forested terrain of mountain basins. Previous studies have shown that measurements of ground-penetrating radar (GPR) velocity can provide accurate estimates of SWE in dry snow. Introduction of liquid water into the snowpack results in a three-phase system that cannot be accurately characterized with GPR velocity alone. We show that measuring the frequency-dependent GPR signal attenuation and velocity provides a direct estimate of the complex dielectric permittivity. Because the imaginary component is a function only of liquid water content, we can utilize both the real and imaginary components of the permittivity to estimate liquid water content, snow density, and SWE using existing empirical relationships that are valid in the pendular regime. We tested this new method at two field sites and found that the estimates were accurate to within 12% of gravimetric methods in both a moist and a dry snowpack. GPR has the potential to provide SWE estimates across large lateral distances over a broad range of snow conditions.

Social network knowledge construction: emerging virtual world pedagogy

Abstract: Purpose – The purpose of this paper is to identify and explore the dynamics of an emerging form of teaching and learning – social network knowledge construction – associated with the use of social networks, particularly 3D virtual world environments such as Second Life. As social network technologies not only frame the way individuals interact and learn, but actually impact on a learner's thinking process and development of future consciousness, new pedagogies are needed to effectively integrate these communication mechanisms into the learning environment.Design/methodology/approach – The paper discusses the purpose and potential use of these networks in the teaching and learning process. Distinguishing features of social network knowledge construction as an emerging pedagogy are identified.Findings – Strategies for incorporating a variety of identified social networks, both in and out of virtual worlds, for teaching and learning are noted.Research limitations/implications – The focus of this emerging ped...

Drucker's Insights on Market Orientation and Innovation: Implications for Emerging Areas in High-Technology Marketing

Abstract: In 1954, Drucker boldly declared that organizations have only two basic functions, marketing and innovation. While true for any organization, this insight is particularly pertinent for technology-based businesses. The complicated environment surrounding high-tech companies creates a great need for sophisticated marketing. Yet these companies continue to have under-developed competencies in marketing and in understanding customer needs. This essay explores Drucker’s insights with respect to two particularly salient issues for high-tech companies: developing and implementing a market orientation and break-through innovations. We review Drucker’s insights and synthesize them with the scholarly research on these issues. Finally, we discuss three emerging areas in high-tech marketing where academics and managers could build on Drucker’s insights to guide future research and practice: market driving, customer co-creation, and corporate social responsibility. These illustrative examples highlight that even today, Drucker’s writings continue to offer remarkable guidance to scholars and managers who are willing to take the time to reflect, understand, and incorporate his insights in the unique context of high-tech industries.

Exploitation of secondary metabolites by animals: A response to homeostatic challenges

Abstract: Synopsis We propose that the exploitation of the bioactive properties of secondary metabolites (SMs) by animals can provide a ‘‘treatment’’ against various challenges that perturb homeostasis in animals. The unified theoretical framework for the exploitation of SMs by animals is based on a synthesis of research from a wide range of fields and although it is focused on providing generalized predictions for herbivores that exploit SMs of plants, predictions can be applied to understand the exploitation of SMs by many animals. In this review, we argue that the probability of SM exploitation is determined by the relative difference between the cost of a homeostatic challenge and the toxicity of the SM and we provide various predictions that can be made when considering behavior under a homeostatic perspective. The notion that animals experience and respond to costly challenges by exploiting therapeutic SMs provides a relatively novel perspective to explain foraging behavior in herbivores, specifically, and behavior of animals in general. We provide evidence that animals can exploit the biological activity of SMs to mitigate the costs of infection by parasites, enhance reproduction, moderate thermoregulation, avoid predation, and increase alertness. We stress that a better understanding of animal behavior requires that ecologists look beyond their biases that SMs elicit punishment and consider a broader view of avoidance or selection of SMs relative to the homeostatic state. Finally, we explain how understanding exploitation of SMs by animals could be applied to advance practices of animal management and lead to discovery of new drugs.

Continuous Profiles of Electromagnetic Wave Velocity and Water Content in Glaciers: An Example from Bench Glacier, Alaska, USA

Abstract: We conducted two-dimensional continuous multi-offset georadar surveys on Bench Glacier, south-central Alaska, USA, to measure the distribution of englacial water. We acquired data with a multichannel 25 MHz radar system using transmitter-receiver offsets ranging from 5 to 150 m. We towed the radar system at 5-10 km h -1 with a snow machine with transmitter/receiver positions established by geodetic-grade kinematic differentially corrected GPS (nominal 0.5 m trace spacing). For radar velocity analyses, we employed reflection tomography in the pre-stack depth-migrated domain to attain an estimated 2% velocity uncertainty when averaged over three to five wavelengths. We estimated water content from the velocity structure using the complex refractive index method equation and use a three-phase model (ice, water, air) that accounts for compression of air bubbles as a function of depth. Our analysis produced laterally continuous profiles of glacier water content over several kilometers. These profiles show a laterally variable, stratified velocity structure with a low-water- content (� 0-0.5%) shallow layer (� 20-30 m) underlain by high-water-content (1-2.5%) ice.

Faculty field guide for promoting student civility in the classroom.

Abstract: Student incivility is defined as rude and disruptive behavior that, when left unaddressed, may spiral into aggressive or violent behavior. Nursing faculty are challenged by uncivil student behavior and many are underprepared to deal with its effects. Some faculty members consider leaving nursing education because of the serious toll that incivility often takes on their personal and professional lives. The impact of student incivility on faculty is especially troubling during a national nursing shortage. The author provides nursing faculty with several ready-to-use strategies for preventing and effectively dealing with student incivility in nursing education.

Reconstruction of the water table from self-potential data: a bayesian approach.

Abstract: Ground water flow associated with pumping and injection tests generates self-potential signals that can be measured at the ground surface and used to estimate the pattern of ground water flow at depth. We propose an inversion of the self-potential signals that accounts for the heterogeneous nature of the aquifer and a relationship between the electrical resistivity and the streaming current coupling coefficient. We recast the inversion of the self-potential data into a Bayesian framework. Synthetic tests are performed showing the advantage in using self-potential signals in addition to in situ measurements of the potentiometric levels to reconstruct the shape of the water table. This methodology is applied to a new data set from a series of coordinated hydraulic tomography, self-potential, and electrical resistivity tomography experiments performed at the Boise Hydrogeophysical Research Site, Idaho. In particular, we examine one of the dipole hydraulic tests and its reciprocal to show the sensitivity of the self-potential signals to variations of the potentiometric levels under steady-state conditions. However, because of the high pumping rate, the response was also influenced by the Reynolds number, especially near the pumping well for a given test. Ground water flow in the inertial laminar flow regime is responsible for nonlinearity that is not yet accounted for in self-potential tomography. Numerical modeling addresses the sensitivity of the self-potential response to this problem.

The relationships between muscle, external, internal and joint mechanical work during normal walking.

Abstract: Muscle mechanical work is an important biomechanical quantity in human movement analyses and has been estimated using different quantities including external, internal and joint work. The goal of this study was to investigate the relationships between these traditionally used estimates of mechanical work in human walking and to assess whether they can be used as accurate estimates of musculotendon and/or muscle fiber work. A muscle-actuated forward dynamics walking simulation was generated to quantify each of the mechanical work measures. Total joint work (i.e. the time integral of absolute joint power over a full gait cycle) was found to underestimate total musculotendon work due to agonist–antagonist co-contractions, despite the effect of biarticular muscle work and passive joint work, which acted to decrease the underestimation. We did find that when the net passive joint work over the gait cycle is negligible, net joint work (i.e. the time integral of net joint power) was comparable to the net musculotendon work (and net muscle fiber work because net tendon work is zero over a complete gait cycle). Thus, during walking conditions when passive joint work is negligible, net joint work may be used as an estimate of net muscle work. Neither total external nor total internal work (nor their sum) provided a reasonable estimate of total musculotendon work. We conclude that joint work is limited in its ability to estimate musculotendon work, and that external and internal work should not be used as an estimation of musculotendon work.