University of Nebraska at Lincoln
  • Lincoln, Nebraska, United States
Recent publications
Mastitis, an inflammatory disease of the mammary gland, imposes a significant financial burden on the dairy sector. However, the specific molecular mechanisms underlying their interactions with goat mammary epithelial cells (GMECs) remain poorly understood. This study aimed to investigate the transcriptomic response of GMECs during infection with E. coli and S. aureus, providing insights into the host-pathogen interactions. Differential expression of gene (DEGs) analysis was done to find genes and pathways dysregulated in the wake of infection. E. coli infection triggered a robust upregulation of immune response genes, including pro-inflammatory che-mokines and cytokines as well as genes involved in tissue repair and remodeling. Conversely, S. aureus infection showed a more complex pattern, involving the activation of immune-related gene as well as those involved in autophagy, apoptosis and tissue remodeling. Furthermore, several key pathways, such as Toll-like receptor signaling and cytokine-cytokine receptor interaction, were differentially modulated in response to each pathogen. Understanding the specific responses of GMECs to these pathogens will provide a foundation for understanding the complex dynamics of infection and host response, offering potential avenues for the development of novel strategies to prevent and treat bacterial infections in both animals and humans.
A major constraint in okra production is damage caused by insect pests, whitefly and jassids, which results in low yield. Identification of resistant varieties is a convenient and eco-friendly way towards sustainable management of insect pests attacking okra. Therefore, population dynamics of the two major pests were recorded in fifteen hybrid varieties of okra during two consecutive years in 2019 and 2020. Significant varietal difference in terms of insect infestation were recorded with, Kajari, NOH-1684, Japani jhar, Singham and Rohini being comparatively resistant varieties. Correlation studies revealed significant negative correlation of whitefly and jassid population with hair density, hair length and total phenols; positive correlation with total protein and total sugar content. The comparative analysis of superoxide dismutase and peroxidase activity revealed varieties more susceptible to whitefly and jassid attack resulted in higher enzyme activity in all the growth stages. The genotypes Kajari NOH-1684, Japani jhar, Singham and Rohini exhibit low infestations of whitefly and jassid, suggesting a tolerance based on their antixenotic properties. To enhance tolerance against these sucking pests, it is recommended to introduce the donor parents Kajari NOH-1684, Japani jhar, Singham and Rohini into okra breeding programs.
The rapid adoption of glyphosate-resistant crops at the end of the 20th century caused a simplification of weed management that relied heavily on glyphosate for weed control. However, the effectiveness of glyphosate has diminished. A greater understanding of trends related to glyphosate use will shed new light on weed adaptation to a product that transformed global agriculture. Objectives were to (1) quantify the change in weed control efficacy from postemergence (POST) glyphosate use on troublesome weeds in corn and soybean and (2) determine the extent to which glyphosate preceded by a preemergence (PRE) improved the efficacy and consistency of weed control compared to glyphosate alone. Herbicide evaluation trials from 24 institutions across the United States of America and Canada from 1996 to 2021 were compiled into a single database. Two subsets were created; one with glyphosate applied POST, and the other with a PRE herbicide followed by glyphosate applied POST. Within each subset, mean and variance of control ratings for seven problem weed species were regressed over time for nine US states and one Canadian province. Mean control with POST glyphosate alone decreased over time while variability in control increased. Glyphosate preceded by a labeled PRE herbicide showed little change in mean control or variability in control over time. These results illustrate the rapid adaptation of agronomically important weed species to the paradigm-shifting product glyphosate. Including more diversity in weed management systems is essential to slowing weed adaptation and prolonging the usefulness of existing and future technologies.
As cities develop more and longer‐range external relations, some have challenged the long‐standing notion that population size indicates a city's power in its urban system. But are population size and network centrality really independent properties in practice, or do larger cities tend to be more central in urban networks? To answer this question, we conducted a systematic literature search and meta‐analysed 41 reported correlations between city size and degree centrality. The results show that population size and degree centrality are significantly and positively correlated for cities across various urban systems ( r = 0.77), but the correlation varies by network scale and type. The size‐centrality association is weaker for global economic and transportation networks ( r = 0.43), and stronger for non‐global social and communication networks ( r = 0.91). This clarifies seemingly contradictory predictions in the literature regarding the association betweensize and centrality for cities.
Polar dielectrics are key materials of interest for infrared (IR) nanophotonic applications due to their ability to host phonon‐polaritons (PhPs) that allow for low‐loss, subdiffractional control of light. The properties of phonon‐polaritons are limited by the characteristics of optical phonons, which are nominally fixed for most “bulk” materials. Superlattices composed of alternating atomically‐thin materials offer control over crystal anisotropy through changes in composition, optical phonon confinement, and the emergence of new modes. In particular, the modified optical phonons in superlattices offer the potential for so‐called crystalline hybrids whose IR properties cannot be described as a simple mixture of the bulk constituents. To date, however, studies have primarily focused on identifying the presence of new or modified optical phonon modes rather than assessing their impact on the IR response. This study focuses on assessing the impact of confined optical phonon modes on the hybrid IR dielectric function in superlattices of GaSb and AlSb. Using a combination of first principles theory, Raman, FTIR, and spectroscopic ellipsometry, the hybrid dielectric function is found to track with the confinement of optical phonons, leading to optical phonon spectral shifts of up to 20 cm ⁻¹ . These results provide an alternative pathway towards designer IR optical materials. This article is protected by copyright. All rights reserved
We investigate the procedure of semi-parametric maximum likelihood estimation under constraints on summary statistics. Such a procedure results in a discrete probability distribution supported on the data points that maximizes the likelihood among all distributions supported on the data points satisfying the specified constraints (called estimating equations). The resultant distribution is an approximation of the underlying population distribution. The study of such empirical likelihood estimation originates from the seminal work of Owen [1], [2]. We investigate this procedure in the setting of misspecified (or biased) constraints, i.e., when the null hypothesis is not true. We establish that the behavior of the optimal weight distribution under such misspecification differ markedly from their properties under the null, i.e., when the estimating equations are correctly specified (or unbiased). This is manifested by certain “singularities” in the optimal distribution, that are not observed under the null. Furthermore, we establish an anomalous behavior of the log-likelihood based Wilks’ statistic, which, unlike under the null, does not exhibit a chi-squared limit. In the Bayesian setting, we establish the posterior consistency of procedures based on these ideas, where instead of a parametric likelihood, an empirical likelihood is used to define the posterior distribution. In particular, we show that this posterior, as a random probability measure, rapidly converges, with explicit convergence guarantees, to the delta measure at the true parameter value. We also illustrate implications of our results in diverse settings such as degeneracies in exponential random graph models (ERGM) for random networks [3], [4], empirical procedures where the constraints are themselves estimated from data [5], and to approximate Bayesian computation based procedures [6], [7]. A novel feature of our work is to connect the likelihood maximization problem to critical points of random polynomials. This yields the mass of the singular weight in the optimal weight distribution as the leading term in a canonical expansion of a critical point of a random polynomial. Our work unveils the possibility that similar random polynomial based techniques could be effective in analyzing a wide class of problems in related areas.
Thome, M, Thorpe, RT, Jordan, MJ, and Nimphius, S. Validity of global positioning system (GPS) technology to measure maximum velocity sprinting in elite sprinters. J Strength Cond Res 37(12): 2438–2442, 2023—The objective of this study was to assess the concurrent validity of 10-Hz wearable Global Positioning System (GPS) technology to measure maximum velocity sprinting ( V max ) relative to Doppler radar in elite sprinters. Data were collected from a single training session performed by elite 100 and 200 m sprinters (males: n = 5; 100 m best times: 10.02 ± 0.07 seconds, range: 9.94–10.10 seconds; 200 m best times: 20.29 ± 0.42 seconds, range: 19.85–20.80 seconds; females: n = 2; age: 28.0 ± 4.2 years; body mass: 65.8 ± 4.6 kg; 100 m best times: 11.18 ± 0.34 seconds; 200 m best times: 22.53 ± 0.04 seconds). Velocity and time data from 16 maximal, 60-m sprint efforts were recorded simultaneously with 10 Hz GPS and 47 Hz radar. Validity was assessed using Bland-Altman 95% limits of agreement (LOA) and intraclass correlation coefficient (ICC), each with respective 95% confidence intervals (CI). V max measured with 10 Hz GPS demonstrated a LOA of −0.11 m·s ⁻¹ (−0.17, −0.05) and an ICC of 0.99 (0.98, 1.0) relative to the radar device.10 Hz GPS overestimated V max by 0.11 m·s ⁻¹ relative to the radar but could still be considered a suitable tool for monitoring external load in elite sprinters. However, the much smaller average annual improvement in this population (∼0.1–0.2%) in comparison with the ∼1% overestimation reduces the utility of 10 Hz GPS to detect meaningful performance changes in maximum velocity.
The proportion of government funding allocated to state transportation budgets has declined as a result of budgetary constraints. This has necessitated a disciplined and efficient allocation of funds for various infrastructure development and rehabilitation projects. Annual average crash costs are typically estimated at the national level to inform resource allocation. These resources can then be used to implement measures to mitigate crashes and the associated costs through development of new technologies for continued improvement of road safety. This study specifically considers 10-year cost predictions associated with injuries, fatalities, and property damage resulting from crashes on highway US-16 in Wyoming. For each of these major crash types, cost predictions are generated from forecasts obtained from appropriately specified Seasonal Autoregressive Moving Average (SARIMA) models that identify important predictors, and which select a temporal correlation structure. The resulting cost projections can be used to inform the Wyoming Department of Transportation on the annual dollar amount associated with these major crash outcomes, along with identified risk factors that can then be used for planning and management of limited infrastructure development funds. This study of US-16 over the 10-year period identified winter months, driving under the influence of alcohol or drugs, heavy trucks, and a few road characteristics as risk factors, which resulted in a total average annual cost estimate of around 865 million dollars.
The consistent rise in current density within electrical wires leads to progressively more substantial heat losses attributed to the Joule effect. Consequently, mitigating the electrical resistivity of copper wires becomes imperative. To attain this objective, the development of a composite material that incorporates a more conductive reinforcement, like graphene, holds great promise. The conception of a copper/graphene composite using a powder metallurgy-based approach is presented. An optimum graphene quantity of 0.06 vol.% was obtained by calculation in order to limit the phenomenon of overlapping layers. This synthesis technique enables the dispersion of graphene and the meticulous control of the interface through the growth of CuO(Cu) nanoparticles that are tightly bonded to the reinforcement. The increase in the hardness of the various materials with separation of the graphene sheets by ultrasonic treatment (55.3 to 67.6 HV) was obtained. It is an indicator of the correct distribution of the reinforcement. The influence on the electrical properties of dendritic copper (ρe = 2.30 µΩ.cm) remains limited, resulting in a modest reduction in electrical resistance of around 1.4%. Nevertheless, for flake copper (2.71 µΩ.cm) and brass (7.66 µΩ.cm), we achieved a more substantial reduction of 2.7% and 10%, respectively. With the improvement of graphene quality, there exists a greater potential for further enhancing the electrical properties.
The null hypothesis that there are no differences in concentrations of digestible energy (DE), metabolizable energy (ME), and net energy (NE) among different sources of bakery meal was tested in a regional experiment involving 5 of the universities on the North Central Coordinating Committee-42 on Swine Nutrition. Eleven sources of bakery meal were procured from the swine producing areas in the United States and included in one diet as the only energy containing ingredient, and each diet was then divided into 5 batches that were used at the University of Illinois, Purdue University, University of Kentucky, University of Nebraska, and North Carolina State University. At each university, diets were fed to 22 growing pigs (2 pigs per diet) that were placed in metabolism crates, and feces and urine were collected for 5 d after a 7-d adaptation period. Diets and collected samples of feces and urine were dried and analyzed for gross energy. The apparent total tract digestibility of dry matter (DM) and gross energy and concentrations of DE, ME, and NE were calculated. Results indicated that there were considerable variation in the nutritional composition among the different sources of bakery meal with relatively large coefficients of variation for crude protein, starch, and acid hydrolyzed ether extract, but it was possible to analyze all sources of bakery meal to account for 100% of the ingredients. The average DE, ME, and NE in the 11 sources of bakery meal was 3,827, 3,678, and 2,799 kcal/kg DM, respectively. However, in contrast to the hypothesis, differences (P < 0.05) among sources of bakery meal in concentrations of DE (3,827 ± 201 kcal/kg DM), ME 3,678 ± 200 kcal/kg DM), and NE (2,799 ± 156 kcal/kg DM) were observed, but the variation among the 11 sources of bakery meal was not greater than what is usually observed among different sources of other ingredients. The differences observed are likely a consequence of the different product streams and production procedures used to produce the bakery meal. In conclusion, the average DE, ME, and NE in 11 sources of bakery meal is close to values previously reported, but there is some variation among sources depending on origin.
The potential of metasurface holography holds significant promise for revolutionary breakthroughs and groundbreaking advancements in imaging, chip-integrated AR/VR technology, and flat optical displays. Traditional diffractive systems, including metasurfaces, display fixed angular behavior due to the grating period defining incidence angles and diffraction limited response. To break this limit, we offer spin-encoded spatially multiplexed metaholograms designing technique facilitating efficient modulation of geometric phases. The proposed technique gives independent control over polarization states, permitting separate optical modifications for different oblique incident angles. Our suggested metasurface illustrates a multifunctional design method using traditional single-resonator geometry, effectively generating three high-fidelity far-field holographic images. Due to simple geometry and dense information multiplexing proposed approach holds potential for different applications, such as holographic optical elements (HOEs), enhanced optical storage, and anti-counterfeiting techniques.
Early childhood (EC) teacher turnover is a chronic issue for the field that affects children, teachers, and programs; yet some teachers choose to remain in the profession. We interviewed EC teachers with the goal of identifying salient motivators and challenges to teaching in their EC workplace and the field generally. Teachers reported parts of their jobs as being both a motivator and a challenge. For example, working with children and families highly motivated teachers and simultaneously posed significant challenges. Findings suggest that the balance of motivators and challenges may be influential in teachers’ decisions to remain in or leave their workplace as well as the EC field. We present recommendations for increasing motivators and decreasing challenges with the goal of improving EC teacher retention.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
7,783 members
J. D. Burton
  • Department of Physics and Astronomy
Tsegaye Tadesse
  • National Drought Mitigation Center
Jon E Pedersen
  • Department of Teaching, Learning and Teacher Education
Nancy Shank
  • Public Policy Center
Lindsey Crawford
  • Department of Biochemistry
1400 R St, 68588, Lincoln, Nebraska, United States
Head of institution
Dr. Ronnie Green