University of Tennessee at Knoxville
  • Knoxville, United States
Recent publications
Coyotes are exposed to many parasites and pathogens of veterinary and zoonotic concern. To assess the prevalence of the diseases caused by these microbes, we opportunistically obtained coyote samples from a variety of sources including a GPS collaring study, rabies testing facilities, wildlife resources agents, and road-side mortalities. We performed necropsies, serological testing, fecal flotations, and molecular analyses on coyotes from Tennessee and South Carolina. Dirofilaria immitis (heartworm) infected 46% (41/89) of coyotes and was associated with eosinophilic alveolitis and arteritis. Paragonimus kellicotti, a zoonotic lung fluke, was found in 24% (17/71) of Tennessee coyotes, including one coyote with extrapulmonary infection affecting the liver and lymph nodes. Trichinella spp., a zoonotic nematode, was present in 17% (12/71) of Tennessee coyotes but was not associated with muscular inflammation. Sarcoptes scabiei, the causative agent of sarcoptic mange, was detected in one Tennessee coyote. Most coyotes (86% [90/105]) were seropositive for Toxoplasma gondii, while 8.5% (9/106) were seropositive for Trypanosoma cruzi, an emerging zoonotic, vector-borne parasite. This study demonstrated that coyotes are commonly exposed to numerous parasites and pathogens that affect people and pets and are excellent sentinels for these diseases.
In 2016, Ahlgren and Samart used the theory of holomorphic modular forms to obtain lower bounds on p-adic valuations related to the Fourier coefficients of three cusp forms. In particular, their work strengthened a previous result of El-Guindy and Ono which expresses a cusp form as a p-adic limit of weakly holomorphic modular forms. Subsequently, Hanson and Jameson extended Ahlgren and Samart’s result to all one-dimensional cusp form spaces of trivial character and having a normalized form that has complex multiplication. Here we prove analogous p-adic limits for several one-dimensional cusp form spaces of trivial character but whose normalized form does not have complex multiplication.
Climate change necessitates the development of improved crops capable of withstanding future weather patterns. Carrots (Daucus carota L.), a crucial vegetable crop of global importance, face unique challenges in seed germination and seedling development due to their complex pollination biology and outcrossing reproduction mode with severe inbreeding depression if selfed. This study investigated the effects of salinity and drought stress on carrot seed germination and seedling development, with focus on the roles of seed priming, cellular processes inhibitors, and biochemical responses. Seed priming agents were hypothesized to enhance stress tolerance by modulating specific cellular and biochemical pathways, such as improving osmotic balance, enhancing antioxidant defense mechanisms, and activating stress-responsive genes. We also hypothesized that specific cellular processes and biochemical pathways influence the germination and early seedling growth of carrot seeds under salinity or drought stress. To test that hypothesis, we evaluated the effects of seed priming with various agents (e.g., water, NaCl, PEG, GA3) on germination rates and seedling vigor. Additionally, we investigated the impact of inhibitors (actinomycin D—inhibitor of transcription, cycloheximide—inhibitor of translation, hydroxyurea—inhibitor of DNA synthesis, cytochalasin—inhibitor of actin polymerization) on seed germination under stress conditions. Biochemical responses, including reactive oxygen species (ROS) levels and antioxidant enzyme activities, were analyzed to identify genotype-specific adaptations indicative of stress tolerance. Our results revealed significant variability in germination rates and seedling growth among the studied carrot experimental lines and commercial cultivars under salinity or drought stress Seed priming enhanced germination and seedling vigor by up to 35% under salinity stress and 28% under drought stress, with notable differences observed across the priming agents. The application of inhibitors highlighted the involvement of specific cellular processes in regulation of seed germination under stress. For instance, actinomycin D reduced germination by 40% under salinity stress. Biochemical analyses indicated genotype-specific responses, with variations in ROS levels and antioxidant enzyme activities such as superoxide dismutase and peroxidase. ROS levels increased by 50% under drought stress, whereas antioxidant enzyme activities varied substantially among genotypes. These findings underscored the importance of genotype-specific adaptations in conferring salinity or drought tolerance in carrot seedlings. Future research integrating omics approaches (e.g., transcriptomics, proteomics, metabolomics) will provide deeper insights into the molecular mechanisms that regulate stress tolerance, to aid in the development of more resilient carrot varieties suitable for cultivation under adverse environmental conditions.
A nanozyme-based aptasensor combines the unique properties of nanozymes with the specificity of aptamers for the detection of various biomolecules. Nanozymes are nanomaterials that possess enzyme-like properties, demonstrating substantial potential for enhancing the sensing capabilities of biosensors. In recent years, the incorporation of nanozymes into biosensors has opened new avenues for the detection of tumor biomarkers. The unique attributes of nanozymes and aptamers lead to biosensors characterized by high sensitivity, specificity, reproducibility and accuracy in analytical performance. This article reviews the research progress of nanozyme-based aptasensors in tumor biomarker detection over the past decade. We categorize these sensors based on their sensing modes and target types, and examine the properties and applications of the nanozymes employed in these devices, providing a thorough discussion of the strengths and weaknesses associated with each sensor type. Finally, the review highlights the strengths and challenges associated with nanozyme-based biosensors and envisions future developments and applications in this field. The objective is to provide insights for improving biosensor performance in tumor biomarker detection, thereby contributing to advancements in precision cancer diagnosis and treatment.
Ethylene is a plant hormone involved in many aspects of plant growth and development as well as responses to stress. The role of ethylene in plant-microbe interactions has been explored from the perspective of plants. However, only a small number of studies have examined the role of ethylene in microbes. We demonstrated that Azospirillum brasilense contains a functional ethylene receptor that we call Azospirillum Ethylene Response1 (AzoEtr1) after the nomenclature used in plants. AzoEtr1 directly binds ethylene with high affinity. Treating cells with ethylene or disrupting the receptor reduces biofilm formation and colonization of plant root surfaces. Additionally, RNA sequencing and untargeted metabolomics showed that ethylene causes wide-spread metabolic changes that affect carbon and nitrogen metabolism. One result is the accumulation of poly-hydroxybutyrate. Our data suggests a model in which ethylene from host plants alters the density of colonization by A. brasilense and re-wires its metabolism, suggesting that the bacterium implements an adaptation program upon sensing ethylene. These data provide potential new targets to regulate beneficial plant-microbe interactions.
Sheet Molding Compound (SMC) is a widely used composite material, particularly in automotive applications, due to its cost-effectiveness, lightweight properties, and adaptability for complex shapes. While E-glass is commonly used as reinforcement in SMC, its strength and stiffness are limited compared to carbon fiber (CF). Previous research has focused on continuous-discontinuous SMC hybrids, combining continuous CF with glass fiber substrates, but these approaches are costly and complex to manufacture. This study explores a novel discontinuous-discontinuous hybrid SMC that combines E-glass SMC (G-SMC) with recycled carbon fiber (rCF) mats, aiming to enhance mechanical properties without a significant cost increase. Two materials were produced, one with and one without rCF, and were tested for flexural, tensile, interlaminar shear, and impact properties. Failure mechanisms were also examined through digital imaging. This approach demonstrates the potential for a cost-effective and practical SMC hybrid suitable for commercial applications in the automotive industry.
Eimeria acervulina is one of several apicomplexan parasites that can cause the economically important disease avian coccidiosis, which is transmitted via the fecal-oral route. It is also a valuable model for exploring interventions capable of reducing the public health risks posed by the related foodborne parasite Cyclospora cayetanensis . Unsporulated (noninfectious) oocysts are shed in the feces and sporulate in the environment to become infectious. In this study, the effect of UV radiation (UVR) on E. acervulina sporulation efficiency was evaluated. Nonstandard wavelengths including 222 and 282 nm have been established as alternatives to standard 254 nm UVR for sterilization. To address the disinfection capability of these nonstandard wavelengths, E. acervulina sporulation was scored following treatment under three wavelengths: 222, 254, or 282 nm. Each wavelength significantly ( P < 0.05) reduced the sporulation rate relative to untreated controls, supporting the utility of nonstandard UVR treatments for coccidian inactivation. Furthermore, infectivity assays showed that chickens administered E. acervulina treated at each wavelength shed significantly fewer oocysts ( P < 0.05) than those that received untreated oocysts, demonstrating a near 3-log reduction and verifying that these alternative wavelengths successfully break the transmission cycle. Owing to its biological similarity with the emerging enteric parasite Cyclospora cayetanensis , it is proposed that disinfection with 222 or 282 nm UVR will likewise be efficacious against Cyclospora . IMPORTANCE Coccidian parasites cause enteric disease in animals and people. For example, Eimeria acervulina imposes major economic burdens on the poultry industry and provides a surrogate for investigating means to mitigate the foodborne risk that Cyclospora cayetanensis poses to human health. Previous work established that UV radiation at 254 nm can inactivate the oocysts of E. acervulina, but radiation at this wavelength harms human skin and eyes. Since nonstandard UVR at wavelengths of 222 and 282 nm shows promise against pathogens like Giardia and Cryptosporidium, the present work sought to determine whether such exposures could arrest E. acervulina development and reduce their infectivity. These nonstandard wavelengths proved capable of disrupting transmission. Epidemiological evidence suggests Cyclospora transmission through the food chain; the use of nonstandard UV wavelengths represents a promising method to inactivate coccidian oocysts, thereby protecting produce supply chains while, specifically in the case of 222 nm, incurring less risk to occupational health.
Laboratory schools were developed more than one hundred years ago on university campuses. The roles, structure, mission, and history of university-based laboratory schools uniquely position them to respond to the needs of their communities and provide resources and leadership for the field. All lab schools have different strengths and resources to support growth and innovation, address issues in the field, and provide leadership to address challenges and opportunities; in collaboration with others they hold the potential to multiply the impact of work conducted independently. This practical article seeks to clarify the role of university laboratory schools while highlighting the responses of five early childhood laboratory schools in the United States to current challenges, illustrating ways that lab schools serve as valuable resources to the field of early childhood education. Together, these schools represent different state and local contexts, serve different populations, and have different programmatic structures. As we seek to address current challenges in early childhood education, we remind others to look to laboratory schools as valuable resources and partners for envisioning new possibilities for the field.
Although variation in effect sizes and predicted values among studies of similar phenomena is inevitable, such variation far exceeds what might be produced by sampling error alone. One possible explanation for variation among results is differences among researchers in the decisions they make regarding statistical analyses. A growing array of studies has explored this analytical variability in different fields and has found substantial variability among results despite analysts having the same data and research question. Many of these studies have been in the social sciences, but one small “many analyst” study found similar variability in ecology. We expanded the scope of this prior work by implementing a large-scale empirical exploration of the variation in effect sizes and model predictions generated by the analytical decisions of different researchers in ecology and evolutionary biology. We used two unpublished datasets, one from evolutionary ecology (blue tit, Cyanistes caeruleus, to compare sibling number and nestling growth) and one from conservation ecology (Eucalyptus, to compare grass cover and tree seedling recruitment). The project leaders recruited 174 analyst teams, comprising 246 analysts, to investigate the answers to prespecified research questions. Analyses conducted by these teams yielded 141 usable effects (compatible with our meta-analyses and with all necessary information provided) for the blue tit dataset, and 85 usable effects for the Eucalyptus dataset. We found substantial heterogeneity among results for both datasets, although the patterns of variation differed between them. For the blue tit analyses, the average effect was convincingly negative, with less growth for nestlings living with more siblings, but there was near continuous variation in effect size from large negative effects to effects near zero, and even effects crossing the traditional threshold of statistical significance in the opposite direction. In contrast, the average relationship between grass cover and Eucalyptus seedling number was only slightly negative and not convincingly different from zero, and most effects ranged from weakly negative to weakly positive, with about a third of effects crossing the traditional threshold of significance in one direction or the other. However, there were also several striking outliers in the Eucalyptus dataset, with effects far from zero. For both datasets, we found substantial variation in the variable selection and random effects structures among analyses, as well as in the ratings of the analytical methods by peer reviewers, but we found no strong relationship between any of these and deviation from the meta-analytic mean. In other words, analyses with results that were far from the mean were no more or less likely to have dissimilar variable sets, use random effects in their models, or receive poor peer reviews than those analyses that found results that were close to the mean. The existence of substantial variability among analysis outcomes raises important questions about how ecologists and evolutionary biologists should interpret published results, and how they should conduct analyses in the future.
This study evaluates the limitations of impact factors in assessing journal quality and explores the competitive dynamics of publishing in top‐tier journals across Accounting, Finance, Management, and Marketing. We document notable cross‐disciplinary variations that challenge the effectiveness of impact factors. Our findings suggest that expanding journal lists within business disciplines by adding high‐impact journals can change the competitiveness of top‐tier publications and may lead to imbalances in promotion and tenure (P&T) decisions. This study contributes to the broader discussion on journal quality metrics in business research, advocating for a nuanced approach to achieve fair and accurate assessments across disciplines.
Immigrants contend with shifting immigration policies and rhetoric during each change in presidential administration. Uncertainty related to changing policies can correlate with immigrant stress, mental health and well-being. Yet, little is known about how immigrant well-being may vary under different presidential administrations. To help explore this relationship, we combined data from two cross-sectional studies, using the same study survey, with first- and second-generation immigrants. In the first study (n = 490), participants responded to questions, as they pertained to experiences under the Trump administration, while participants in the second study responded to experiences under the Biden administration (n = 306). The current study was designed to examine policy-related stress, discrimination, resilience, and mental health symptoms under the two most recent presidential administrations. Linear regression analyses were conducted with two mental health outcomes, depression and anxiety. Findings suggest that participant responses under the Trump administration correlated with higher stress, discrimination, and mental health symptoms, while resilience served as a protective factor. No interaction effects were found. Implications are presented specific to service provision and policymaking.
Background Few studies have empirically examined the impact of school salad bars on elementary students’ fruit and vegetable (FV) consumption within the National School Lunch Program (NSLP). This natural experiment evaluated the impact of salad bars on FV selection, intake, and waste within elementary schools. Methods Seven school pairs, matched on Title I status and percentage of students from ethnic or racial minority backgrounds, were randomly selected. All schools served pre-portioned FV at baseline. One school within each pair received a salad bar; the other continued to serve pre-portioned FV (Control). Digital imagery plate waste methods were applied at baseline and 4–6 weeks after schools installed salad bars (post). Images were rated in the laboratory (ICCs = .94-.99) to determine FV selection, intake, and waste (servings [1 NSLP serving = ½c]). Multilevel modeling evaluated group (Salad Bar vs Control) and time (baseline vs post) differences and group-by-time interactions. Differences in outcomes by Title I status were also examined. Results Across schools, mean NSLP participation was 54%. N = 6,623 trays were included (n = 3,273 Salad Bar; n = 3,350 Control). Students in Salad Bar schools selected (+ .44c) and consumed (+ .36c) more FV at post, compared to baseline. Control students decreased FV selection (-.05c) with no change in intake from baseline to post. Group, time, and group-by-time interactions were significant (ps < .0001). When examined separately, results suggest that these effects are driven by fruit. Salad Bar students increased fruit selection (+ .45c), intake (+ .36c), and waste (+ .09c) from baseline to post; no significant changes were observed in Controls. There was no significant change in vegetable selection, intake or waste for either group. Findings did not differ based on Title I status. Conclusions Salad bars were effective in increasing elementary school students’ fruit selection and intake, yet did not increase vegetable selection or intake. Additional efforts are needed to increase vegetable intake and minimize fruit waste from salad bars. Consistent findings across schools, regardless of Title I status, suggest potential for salad bars to yield increased fruit intake across socioeconomic groups. Findings can inform policies designed to increase FV intake within the NSLP. Trial registration This investigation reports results of a systematic evaluation of school salad bars and does not meet criteria for a clinical trial, yet was retrospectively registered (10/28/22) in clinicaltrials.gov (NCT05605483) as an observational study.
In a recent article in this journal, Baron (2025) argues that we can appropriately trust unexplainable artificial intelligence (AI) systems, so explainability is not necessary for AI’s trustworthiness. In this commentary, I argue that Baron is wrong. I first offer a positive argument for the claim that explainability is necessary for trustworthiness. Drawing on this argument, I then show that Baron’s argument for thinking otherwise fails.
Over the past decade, video games have dramatically risen in popularity, and marketers have started recognizing the research opportunities video games provide. However, much of the current research in the gaming space focuses on the video game experiences of individual consumers, whereas other participants in the video game ecosystem are often ignored. In addition, research frequently uses traditional data collection and analysis techniques that do not adequately account for the unique features of the data generated within this ecosystem. In this article, using a framework based on service-dominant logic and the customer journey, we identify six distinct pillars embedded in the video game ecosystem and describe the types of data generated through interactions among them. We then present three challenges with data gathering and analysis that arise from the co-creation of value within the video game ecosystem. Finally, we outline adaptations marketers can make to address these challenges and present future research directions to help access and analyze data generated throughout the video game ecosystem.
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Francisco N. Barrera
  • Department of Biochemistry and Cellular and Molecular Biology
Dima Bolmatov
  • Department of Physics & Astronomy
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