Bridge Load Posting Based on Load Testing

AASHTO’s Manual for Bridge Evaluation (MBE) provides guidance for analytically evaluating bridge capacity based on available design information and the results of field inspections. This analysis results in a rating factor (RF), which quantifies a bridge’s safe load carrying capacity. RF accuracy, however, depends on the availability of information about structural details and material properties. As such, load rating bridges without design plans is difficult as field inspections alone often cannot provide enough information to perform detailed analysis. In many instances this means that a bridge would possess a substandard rating factor (RF \u3c 1.0) simply due to the conservative assumptions required to perform traditional analysis. The most effective method for safely modifying such conservative theoretical rating factors is through load testing. Load testing measures actual bridge behavior and, for most bridges in good health, finds an increase in load rating is justified. This project utilized load testing to load rate 14 bridges in Kentucky that lack structural plans. Researchers first determined theoretical ratings using MBE-prescribed methods. For information typically taken from design plans, but which could not be measured directly, data-backed methods for making conservative assumptions were developed. For most bridges included in the study, theoretical rating factors alone suggested load postings were necessary. Load testing was then carried out utilizing tandem rear-axle dump trucks with measured axle weights. Multiple single-lane load cases were selected to maximize the effects being rated. Strain data were collected in real time using a wireless reusable strain gage system. Using these data, researchers computed a field test adjustment factor using MBE methods which directly modified the calculated theoretical RFs. Ultimately, load testing provided sufficient evidence to safely recommend that load postings were not necessary for any bridges in this study

Engaging Nurses in Effective Cost of Care Conversations to Address Cancer-Related Financial Toxicity: Results from an Exploratory Survey

Few evidence-based trainings exist on how to equip healthcare providers, particularly nurses, with the skills to engage in cost of care conversations with patients/caregivers to mitigate the impact of cancer-related financial toxicity. This study evaluated a pilot training developed in collaboration with Triage Cancer® to prepare oncology nurses to identify and assist patients/caregivers facing financial and/or legal barriers to care. Ten pediatric oncology nurses completed the training and pre/post-surveys on behaviors related to financial and legal need screening, frequency and comfort level of answering questions, knowledge, and behavior changes, along with training evaluation questions. At baseline, six nurses reported never screening for financial needs and nine for legal needs. Following the training, seven nurses stated they were likely to screen for financial/legal needs. At six months post-training, nurses had referred 85 patients/caregivers to financial/legal navigation services. Comfort levels in answering financial/legal questions increased by 6.5 points and knowledge scores increased by 1.7 points post-training. Most nurses recommended this training to other healthcare providers who work with patients with cancer and their caregivers. This study highlights the importance of providing oncology nurses with resources to engage in cost of care conversations and oncology financial legal navigation programs to mitigate the impact of cancer-related financial toxicity

Effects of Phosphogypsum, Phsophorus and Lime on Andropogon gayanus Kunth

There are several factors which determine the low animal productivity in the tropics. Among these factors, inadequate nutrition is the most limiting one followed by the low natural fertility and high acidity of the soils in these regions. Previous findings have shown important soil nutrient deficiencies in some Brazilian cerrado soils. Malavolta (1952) demonstrated sulfur (S) deficiencies, while Werner et al. (1967) found plant response to S. Responses to phosphorus addition are very common in this kind of soil and in tropical America there are rates of phosphorus being applied, which sometimes are uneconomical for the formation and maintenance of pastures. The combination among tolerant varieties to the low phosphorus disponibility, the correct application of phosphatic fertilizers and the correction of the soil acidity, to reduce phos­phorus fixation, would be an effective mean for its economical utilization in many tropical soils with high fixing capacity. In many cases, tropical grasses have shown little or no response to liming (Emrich, 1967). Being adapted to high acidity, they respond only to calcium and/or magnesium fertilization, when used at rates that are not enough to affect pH and the exchangeable aluminium (Ciat, 1977); however, there is a differential tolerance to soil acidity among forages, each species or variety in the same species having a different behavior. The purpose of this paper was to investigate possible deficiencies and responses of andropogon grass to rates of sulfur, phosphatic fertilization, and liming on cerrado soil

Extracellular vesicles released by ALL patients contain HNE-adducted proteins: Implications of collateral damage

Off-target neuronal injury is a serious side-effect observed in cancer survivors. It has previously been shown that pediatric acute lymphoblastic leukemia (ALL) survivors have a decline in neurocognition compared to healthy age-matched counterparts. Elevated oxidative stress has been documented to be a mediator in off- target tissue damage in cancer survivors. Early detection of oxidative stress markers may provide an opportunity to prevent off-target tissue damage. Extracellular vesicles (EVs) have surfaced as a potential diagnostic tool due to molecular cargo they contain. We investigated the potential for EVs to be a sensitive indicator of oxidative stress and off-target tissue damage by isolating EVs from pediatric ALL patients throughout their first 2 months of treatment. EVs were measured throughout the collection points for: 1) number of EV particles generated using nanoparticle tracking analysis (NTA); 2) markers of neurons (NeuN), astrocyte activation (GFAP), neuronal stability (BDNF), 3) markers of pre-B cell ALL (CD19 and CD22); and) 4-hydroxy-2-nonenal (HNE) adducted proteins. HNE protein adductions were measured in the patient sera and CSF. Pro-inflammatory cytokine levels were also measured in patient sera because of their contribution to oxidative stress and neuronal injury. Our results: 1) demonstrate EVs are a sensitive indicator of oxidative damage; 2) suggest EVs as a marker of a decline in neuronal stability; and 3) show the presence of leukemia has a greater contribution to pro-inflammatory cytokine production in the patient’s serum than the cancer treatment. Spe- cifically, we observed a significant decrease in cytokine levels (e.g., TNF-α, IL-1β, IL-6, and IL-8) following the initiation of treatment, highlighting the influence of leukemia burden on systemic inflammation. The results support the utilization of EVs as a sensitive marker of oxidative stress and off-target tissue damage

ANALYSIS OF PTFE RADIAL LIP SEALS FOR WHEEL BEARING APPLICATIONS

A numerical analysis was conducted to investigate the viscoelastic effects of nonlinear materials on the sealing zone and contact pressure distribution of radial lip seals in a conventional geometric topology. The use of nonlinear materials in radial lip seal applications is desirable to improve operation and reliability of rotating machinery due to their high operating temperatures, chemical compatibility, and low friction coefficients. Examples include, but are not limited to, seals within industrial air compressors, turbine engines, aircraft landing systems, chemical processing equipment, and Freon pumps. This work focuses on analyzing the nonlinear viscoelastic response of pure Polytetrafluoroethylene (PTFE) and PTFE Glass MoS2 (GM) used in a radial lip seal used in railroad wheel bearings, subject to a specified radial shaft interference fit. A 2-D axisymmetric multi-scale finite element model (FEM) is developed that includes a railroad wheel bearing seal with a preload garter spring, rigid shaft, and contact elements along both regions of the sealing width. The viscoelastic effect is modeled using a two term Prony series that was obtained by curve fitting experimental relaxation modulus data obtained in previous work from Dynamic Mechanical Analysis (DMA) test data to the relative shear moduli. Results are presented showing the contact pressure distributions of varying scraper angles, barrel angles, garter spring stiffnesses, R-values, and the materials of interest. Discussion regarding the validity of the linear viscoelastic material assumption for pure PTFE and PTFE-GM is given. Regions of plasticity are identified for typical interference fits and recommendations are made for radial lip seal design parameters that result in non-plastic behavior, which is desirable from a sealing standpoint, and provide adequate sealing performance

Molecular mechanisms and comparative transcriptomics of diapause in two corn rootworm species (Diabrotica spp.)

Diapause is a programmed developmental arrest that can occur at any developmental stage depending on species, but the mechanisms that underscore embryonic diapause are poorly understood. Here, we identified molecular mechanisms underscoring distinct phases of diapause in the Diabrotica spp. complex. This species complex in- cludes economically significant agricultural pests, notably the western corn rootworm (WCR) and northern corn rootworm (NCR), which cause major losses in maize production. Rootworms undergo an obligate embryonic diapause to synchronize their life cycles with host plants, and we sequenced transcriptomes from both species at five time points (pre-diapause, diapause initiation, diapause maintenance, diapause termination, and post- diapause). Our results indicate that transcriptional regulation is dynamic during diapause. Diapause initiation involves shutdown of the cell cycle by downregulating cyclin-related genes, downregulation of aerobic meta- bolism, with concurrent upregulation of stress-related genes, especially heat shock proteins, the proteasome, and immune-related genes. During post-diapause development, there is a dramatic activation cellular respiration, which may be controlled by insulin signaling. Comparative transcriptomic analyses between WCR and NCR indicated that while many gene expression changes were conserved across species, overall gene expression profiles were distinct, indicating that many transcriptional changes are species-specific, despite the close phylogenetic relationship and phenotypic similarity between these species. This study sheds light on the suite of mechanisms that allow some organisms to pause the symphony of cellular events that occur during embryonic development and persist for several months as a tiny egg. Further, the mechanisms identified here may contribute to further research and pest management efforts in this economically important pest group

Managing Woody Weeds in Grazing Ecosystems: Application for Tropical Woodlands of North-eastern Australia

Shrub invasion of tropical woodlands is reducing the viability of native ecosystems as well as the livestock industry, After shrub invasion, forage supply is reduced and over-grazing and soil erosion are exacerbated. We propose a non-equilibrium model of the system and use that model to develop hypotheses and design experiments to test both competition- and disturbance-based management regimes. This model proposes that disturbance in the form of burning is the primary limiting factor in excluding and limiting shrub seedling establishment and suggests that management decisions focus on maintaining adequate herbaceous biomass for a burning regime that limits woody plant success