University of Arkansas
  • Fayetteville, AR, United States
Recent publications
Bovine respiratory disease (BRD), as one of the most common and costly diseases in the beef cattle industry, has significant adverse impacts on global food security and the economic stability of the industry. The bovine respiratory microbiome is strongly associated with health and disease and may provide insights for alternative therapy when treating BRD. The niche-specific microbiome communities that colonize the inter-surface of the upper and the lower respiratory tract consist of a dynamic and complex ecological system. The correlation between the disequilibrium in the respiratory ecosystem and BRD has become a hot research topic. Hence, we summarize the pathogenesis and clinical signs of BRD and the alteration of the respiratory microbiota. Current research techniques and the biogeography of the microbiome in the healthy respiratory tract are also reviewed. We discuss the process of resident microbiota and pathogen colonization as well as the host immune response. Although associations between the microbiota and BRD have been revealed to some extent, interpreting the development of BRD in relation to respiratory microbial dysbiosis will likely be the direction for upcoming studies, which will allow us to better understand the importance of the airway microbiome and its contributions to animal health and performance.
Background The goal of this study was to evaluate marker-assisted selection (MAS) in broiler chickens using previously mapped gene regions associated with ascites syndrome incidence. The second-generation MAS products were assessed for impact on ascites phenotype and whether there were associated changes in important production traits. Previously, we used whole genome resequencing (WGR) to fine-map 28 chromosomal regions as associated with ascites phenotype in our experimental ascites broiler line (Relaxed, REL) based on a hypobaric chamber challenge. Genotypes for single nucleotide polymorphisms (SNPs) in mapped regions on chromosomes 2 and 22, were used for MAS in our REL line. After two generations, birds homozygous for the genotypes associated with resistance for both chromosomal regions were established. The MAS F 2 generation was then compared to the REL line for ascites susceptibility and 25 production traits. Results Selection based on SNPs in the carboxypeptidase Q (CPQ, Gga2) and leucine rich repeat transmembrane neuronal 4 (LRRTM4, Gga22) gene regions resulted in a sex- and simulated altitude- dependent reduction of ascites incidence in two F 2 cohorts of the MAS line. Comparisons of the F 2 MAS and REL lines for production traits when reared at ambient pressure found no significant negative impacts for feed intake (FI), feed conversion ratio (FCR), or deboned part yields for either sex for two F 2 cohorts. There were, however, improvements in the MAS for full-trial body weight gain (BWG), FCR, absolute and relative tender weights, and relative drumstick weight. Conclusions These results validate the mapping of the 28 chromosomal regions and demonstrate that fine mapping by WGR is an effective strategy for addressing a complex trait; it also stands as the first successful SNP-based selection program against a complex disease trait, such as ascites. The MAS line is comparable and, in some instances, superior, in growth performance to the REL control while being more resistant to ascites. This study indicates that MAS based on WGR can provide significant breeding potential in agricultural systems.
We examined how prior experience encountering targets affected attention allocation and event-based prospective memory. Participants performed four color match task blocks with a difficult, but specified prospective memory task (Experiment 1) or an easier, but unspecified prospective memory task (Experiment 2). Participants were instructed to search for targets on each block. Participants in the prior experience condition saw targets on each block, participants in the no prior experience condition only saw targets on the fourth block, and, in Experiment 2, participants in the mixed prior experience condition encountered some of the targets on the first three blocks, and saw all the targets on the fourth block. In Experiment 1, participants in the no prior experience condition were less accurate at recognizing targets and quicker to respond on ongoing task trials than participants in the prior experience condition. In Experiment 2, we replicated the effect of prior experience on target accuracy, but there was no effect on ongoing trial response time. The mixed experience condition did not vary from the other conditions on either dependent variable, but their target accuracy varied in accordance with their experience. These findings demonstrate that prospective memory performance is influenced by experience with related tasks, thus extending our understanding of the dynamic nature of search efforts across related prospective memory tasks. This research has implications for understanding prospective memory in applied settings where targets do not reliably occur such as baggage screenings and missing person searches.
Piezoresponse force microscopy is used to study the velocity of the polarization domain wall in ultrathin ferroelectric barium titanate (BTO) films grown on strontium titanate (STO) substrates by molecular beam epitaxy. The electric field due to the cone of the atomic force microscope tip is demonstrated as the dominant electric field for domain expansion in thin films at lateral distances greater than about one tip diameter away from the tip. The velocity of the domain wall under the applied electric field by the tip in BTO for thin films (less than 40 nm) followed an expanding process given by Merz’s law. The material constants in a fit of the data to Merz’s law for very thin films are reported as about 4.2 KV/cm for the activation field, $$E_{\mathrm{a}}$$ E a , and 0.05 nm/s for the limiting velocity, $$v_{\infty }$$ v ∞ . These material constants showed a dependence on the level of strain in the films, but no fundamental dependence on thickness.
Ectomycorrhizal (EM) fungal communities that associate with invading pines (Pinus spp.) are expected to be poor in species diversity. However, long-term successional trajectories and the persistence of dispersal limitations of EM fungi in the exotic range are not well understood. We sampled the roots and surrounding soil of Pinus elliottii and P. taeda trees invading mountain grasslands of Argentina. We also sampled the EM fungal spore bank in grassland soil near (∼150 m) and far (∼850 m) from the original pine plantations. We found 86 different co-invasive EM fungal OTUs. Differential dispersal capacities among EM fungi were detected in the spore bank of grassland soil, but not under mature pines. After thirty years of invasion, the age, but not the degree of spatial isolation of pine individuals affected the EM fungal composition. We showed how EM fungal succession occurs during pine invasions, which may have clear consequences for ecosystem functioning of co-invaded sites.
Background Iron is a crucial element for bacterial survival and virulence. During Salmonella infection, the host utilizes a variety of mechanisms to starve the pathogen from iron. However, Salmonella activates distinctive defense mechanisms to acquire iron and survive in iron-restricted host environments. Yet, the comprehensive set of the conditionally essential genes that underpin Salmonella survival under iron-restricted niches has not been fully explored. Results Here, we employed transposon sequencing (Tn-seq) method for high-resolution elucidation of the genes in Salmonella Typhimurium ( S. Typhimurium) 14028S strain required for the growth under the in vitro conditions with four different levels of iron restriction achieved by iron chelator 2,2′-dipyridyl (Dip): mild (100 and 150 μM), moderate (250 μM) and severe iron restriction (400 μM). We found that the fitness of the mutants reduced significantly for 28 genes, suggesting the importance of these genes for the growth under iron restriction. These genes include sufABCDSE , iron transport fepD , siderophore tonB , sigma factor E ropE , phosphate transport pstAB, and zinc exporter zntA . The siderophore gene tonB was required in mild and moderate iron-restricted conditions, but it became dispensable in severe iron-restricted conditions. Remarkably, rpoE was required in moderate and severe iron restrictions, leading to complete attenuation of the mutant under these conditions. We also identified 30 genes for which the deletion of the genes resulted in increased fitness under iron-restricted conditions. Conclusions The findings broaden our knowledge of how S. Typhimurium survives in iron-deficient environments, which could be utilized for the development of new therapeutic strategies targeting the pathways vital for iron metabolism, trafficking, and scavenging.
Camping is a salient economic contributor to nature-based tourism and among its most susceptible subsectors to weather and climate change, yet it remains understudied. Accordingly, we investigate (1) the effects weather on camping business performance and (2) the potential value camping can capture from weather. The study is operationalized using daily recreational vehicle accommodation sales (2007–2016) for two camping businesses in the Southwest and Central climate regions of the United States matched with climate data (1984–2020). Results establish (1) weather shares a direct relationship with camping business sales where effect sizes range from small to moderate and (2) camping businesses can capture financial value from weather. Theoretical and practical implications are provided.
We propose machine learning-based (ML) methods to accelerate convergence to global solutions for the AC Optimal Power Flow (AC-OPF) problem. In particular, for the non-convex AC-OPF problem, optimality-based bound tightening (OBBT) has been observed to be a very effective approach for tightening the variable domains, thus leading to tight convex relaxations that are nearly global optimum solutions. However, by construction, OBBT is computationally expensive even on medium-scaled power networks. To address this issue, we propose a novel ML-based policy to replace the exhaustive algorithm of OBBT by choosing a subset of variables whose tightening of bounds can still contribute to the best improvement of the convex relaxation of the AC-OPF problem. To this end, we leverage historical data of load profiles for a test system to learn a map between the system loading and subset selection of variables which will need to participate in the OBBT algorithm, thus enabling us to find near-global optimal solutions at faster run-times. Finally, we present detailed numerical studies on a few medium-sized benchmark instances, on which we observe up to 6.3× speed-up in OBBT run times.
The Vestibular/Ocular-Motor Screening (VOMS), an important component in acute (<72 h) sport-related concussion (SRC) assessment, is increasingly used alongside the Sport Concussion Assessment Tool (SCAT) and as part of the Military Acute Concussion Evaluation 2 (MACE2). VOMS demonstrates clinically useful diagnostic accuracy for acute SRC and improves the overall utility when added to the SCAT3. However, potential overlap among VOMS’s vestibular and oculomotor items suggests the possibility of a more efficient version. VOMS and SCAT3 scores were analyzed for 3,958 preseason (47.8% female) and 496 acute-SRC (37.5% female) NCAA-DoD Concussion Assessment, Research, and Education (CARE) consortium collegiate athlete evaluations. Analyses revealed very large effect sizes (d = 2.39–2.45) and high correlations (rho = 0.95–0.99) among all VOMS items except near point of convergence distance (d = 0.79, rho ≤ 0.341). Receiver operating characteristic (ROC) curve analyses showed clinically useful discriminative utility for VOMS Total (AUC = 0.85) and the VOMS Total change score, where pretest symptoms were incorporated (AUC = 0.81). A modified VOMS (mVOMS) consisting of four items (smooth pursuits, horizontal saccades, horizontal vestibulo-ocular reflex, visual motion sensitivity) yielded identical AUCs to VOMS Total. Integer cutoff analyses suggest a score of ≥4 for VOMS Total and ≥4 for mVOMS Total optimizes concussion identification. Incorporating VOMS or mVOMS into SCAT3 (AUC = 0.79) significantly improved the combined tool’s acute utility for acute concussion identification by a maximum of 4% (SCAT3+VOMS AUC = 0.84, SCAT3+mVOMS AUC = 0.83). Future versions of SCAT or MACE may want to consider incorporating a more parsimonious VOMS for the purpose of identifying acute concussion.
Individuals infer men's formidability through various facial and bodily features. Such inferences covary with perceptions of men's personalities and motivational states, potentially informing subsequent affiliative decisions. Within these inferences could be an implicit understanding of men's preferred humor styles. Across four studies, this research considered perceptions of men's proclivity to employ four humor styles through different formidability cues: upper body strength (Study 1), muscularity (Study 2), facial width-to-height ratio (Study 3), and neck musculature (Study 4). A relatively consistent perception emerged of formidable men as more likely to use aggressive humor. Conversely, an absence of formidability cues elicited perceptions of increased likelihood to use self-defeating humor. We interpret results from an evolutionary perspective for how individuals can identify behavioral strategies through morphological features.
Metronomic chemotherapy (MET) has been developed to address the shortcomings of maximum-tolerated chemotherapy (MTD) in regard to toxicity and development of resistance mechanisms in the tumor. In colorectal cancer (CRC), MET is a promising novel strategy to treat locally advanced malignancies when used as neoadjuvant chemotherapy (NAC). However, so far there are no preclinical studies to assess the impact of MET NAC in CRC to assess the benefits and challenges of this approach. Here, we used a primary model of CRC (via azoxymethane) to analyze longitudinal changes in angiogenesis in primary tumors under MET and MTD NAC using a combination of diffuse reflectance spectroscopy and mRNA expression (via qPCR). Our results show that MET and MTD NAC lead to increased mean tissue oxygen saturation (8% and 5%, respectively) and oxyhemoglobin (15% and 10%) between weeks 2 and 5 of NAC, and that such increases are caused by distinct molecular signatures in the angiogenic program. Specifically, we find that in the MET group there is a sustained increase in Hif-1a, Aldoa, and Pgk1 expression, suggesting upregulated glycolysis, whereas MTD NAC causes a significant reduction in the expression of the aforementioned genes and of Vegf, leading to vascular remodeling in MTD-treated tumors. Taken together, this study demonstrates the ability of combined optical and molecular methodologies to provide a holistic picture of tumor response to therapy in CRC in a minimally invasive manner.
Recollection rejection (a form of memory monitoring) involves rejecting false details on the basis of remembering true details (recall to reject), thereby increasing memory accuracy. This study examined how recollection rejection instructions and feedback affect memory accuracy and false recognition in 5-year-olds, 6- and 7-year-olds, 8- and 9-year-olds, and adults. Participants (N = 336) completed three study–test phases. Instructions and item-level feedback were manipulated during the first two phases, with the third phase including a test containing no instructions or feedback to evaluate learning effects. As predicted, in the younger children, as compared with the older children and adults, we found reduced accuracy scores (hits to studied items minus false alarms to related lures), reduced recollection rejection to related lures, and increased false recognition scores. We also found that, in the third phase, prior feedback reduced false recognition scores, potentially by improving monitoring, and typical developmental differences in false recognition were eliminated. However, there were mixed findings of instructions and feedback, and in some conditions these interventions harmed memory. These findings provide initial evidence that combining instructions and feedback with repeated task practice may improve monitoring effectiveness, but additional work is needed on how these factors improve and sometimes harm performance in young children.
Despite presenting several physiological and social benefits, yawning remains a highly stigmatized behavior across various cultures. Given evidence for an association between illness and the proclivity to yawn, it could be possible that yawning provides a heuristic cue to disease transmission between conspecifics. This aversion to yawning could thus serve as a disease avoidance strategy. The current study identified how individual differences in disease avoidance motivations could foster stigmatization of yawning. Participants completed personality inventories, including those related to disease avoidance and disgust, while indicating their attitudes toward various bodily functions. Individual differences in germ aversion and pathogen disgust were particularly associated with stigmatization of yawning, such that higher levels of these traits fostered greater aversion toward yawning. These data provide initial evidence for how fundamental social motives can facilitate reactions to involuntary behaviors.
Expansion of dicamba-resistant crops increased the frequency of off-target movement issues, especially in the midsouthern United States. Six field trials were conducted over two growing seasons with the purpose to determine the contribution of volatilization and physical suspension of particles to the off-target movement of dicamba when applied with glyphosate and imazethapyr - a non-volatile herbicide used as a tracer for physical off-target movement. Applications included dicamba at 560 g ha⁻¹, glyphosate at 1260 g ha⁻¹, and imazethapyr at 105 g ha⁻¹. Applicators include glyphosate with dicamba to increase the spectrum of weed control from these applications; however, this addition increases potential for dicamba volatilization. Following application of the mixture, air samplers were placed in the field to collect dicamba and imazethapyr. Results showed there was at least 50 times more dicamba than imazethapyr detected even though the dicamba:imazethapyr ratio applied was 5.3:1. Dicamba was detected in the treated area and the off-site locations and all intervals of air sampling, ranging from 126 to 5990 ng. No more than 37.5 ng of imazethapyr was detected during the first 24-h after application (HAA) inside the treated area. Imazethapyr was only detected in 9 of the 20 sampling combinations during these experiments, and most of these detections (6) occurred during the first 24 HAA and inside the treated area. While some movement from the suspension of particles occurred based on the detection of imazethapyr in air samples, results show that most dicamba detection was due to the volatilization of the herbicide.
Metal-organic frameworks (MOFs) have escalated much attention as innovative electrode materials for supercapacitors applications due to their high porosity, adequate active sites, and tunable structures. However, most MOFs show low capacitance, which limits their application in energy storage devices. In this study, a new MOF composite containing poly(4-aminothiophenol) (PAT), Zn, Ni, and reduced graphene oxide (rGO), abbreviated as PATZ1N2G2-MOF, was fabricated by a one-step simple hydrothermal method and its electrochemical characteristics for supercapacitor applications were examined. The structural characterization of the proposed MOF exhibited successful synthesis of a highly porous and nanoscale crystalline spherical PATZ1N2G2-MOF configuration mainly spread on extra thin nano-sheets of rGO. The convenient mixed spherical structure of PATZ1N2-MOF and rGO Nano-sheets facilitates more electrochemically active regions and more accessible routes for charge and mass transfer, developing a specific capacitance as high as 1230.23F g⁻¹ at a current density of 1.0 A g⁻¹ as well as excellent capacitance retention of 89.8% after 3000 repetitive cycles. Moreover, the capacity of the modified positive electrode for the 2-electrode setup was obtained to be 93.31F g⁻¹, producing a high energy and power density of 33.17 Wh kg⁻¹ and 188.35 W kg⁻¹, respectively. The experimental results revealed the superior supercapacitive behavior of the PATZ1N2G2-MOF/NF electrode.
The lattice thermal conductivity (κl) plays a key role in the performance of thermoelectric (TE) materials, where the lower values lead to higher figure of merit values. Two-dimensional (2D) group III-VI monolayers such as InTe are promising materials for TE energy generation owing to their low κl that lead to high TE figure of merit values. In this work, we investigate the influence of the lattice anharmonicity on the lattice thermal conductivity of InTe monolayer. The thermodynamic parameters are calculated by using the self-consistent phonon (SCP) theory. The κl value of the InTe monolayer is obtained to be 0.30 Wm⁻¹ K⁻¹ by using the standard Boltzmann transport equation (BTE) approach, while it is 3.58 Wm⁻¹ K⁻¹ by using SCP + BTE approach. These results confirm the importance of the anharmonic effects on the κl value, where it was found to be significantly higher (91%) using the SCP + BTE approach than that obtained using the standard BTE approach.
Objective: To develop an instrument to examine tobacco-free campus policy components. Participants: Missouri two- and four-year, specialized/technical, and religious colleges and universities (N = 76). Methods: The instrument was informed via literature review and expert interviews. Coder agreement was strong (κ = .80). Qualitative policy language examples were identified. Results: Model policy components including consideration for population, prohibited products, location restrictions, enforcement, consequences, promotions, communications, cessation, designated smoking areas and exemptions; comprehensive policies included all populations, for all tobacco products, and at all locations on the campus. Nineteen campuses had comprehensive tobacco-free policies, five had comprehensive smoke-free policies (cigarettes and e-cigarettes), and no policy included all model components. Fifty-two were non-comprehensive. Conclusions: This instrument can allow campuses to identify components for comprehensive and model tobacco-free campus policies and assist officials in improving policy language. Future research can use this instrument to examine the effectiveness of components and their impact on tobacco use outcomes.
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7,482 members
Ainong Shi
  • Department of Horticulture
Ioannis E. Tzanetakis
  • Department of Entomology and Plant Pathology
Rohana Liyanage
  • Department of Chemistry and Biochemistry
Komala Arsi
  • Department of Poultry Science
Malcolm Cleaveland
  • Department of Geosciences
72701, Fayetteville, AR, United States
Head of institution
Dr. Joseph E. Steinmetz (Chancellor)