University of Tennessee Southern
UniversityPulaski, United States
Research output, citation impact, and the most-cited recent papers from University of Tennessee Southern (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from University of Tennessee Southern
Deep eutectic solvents (DESs) are an emerging class of non-aqueous solvents that are potentially scalable, easy to prepare and functionalize for many applications ranging from biomass processing to energy storage technologies. Predictive understanding of the fundamental correlations between local structure and macroscopic properties is needed to exploit the large design space and tunability of DESs for specific applications. Here, we employ a range of computational and experimental techniques that span length-scales from molecular to macroscopic and timescales from picoseconds to seconds to study the evolution of structure and dynamics in model DESs, namely Glyceline and Ethaline, starting from the parent compounds. We show that systematic addition of choline chloride leads to microscopic heterogeneities that alter the primary structural relaxation in glycerol and ethylene glycol and result in new dynamic modes that are strongly correlated to the macroscopic properties of the DES formed.
The Osiris gene family, first described in Drosophila melanogaster, is clustered in the genomes of all Drosophila species sequenced to date. In D. melanogaster, it explains the enigmatic phenomenon of the triplo-lethal and haploinsufficient locus Tpl. The synteny of Osiris genes in flies is well conserved, and it is one of the largest syntenic blocks in the Drosophila group. By examining the genome sequences of other insects in a wide range of taxonomic orders, we show here that the gene family is well-conserved and syntenic not only in the diptera but across the holometabolous and hemimetabolous insects. Osiris gene homologs have also been found in the expressed sequence tag sequences of various other insects but are absent from all groups that are not insects, including crustacea and arachnids. It is clear that the gene family evolved by gene duplication and neofunctionalization very soon after the divergence of the insects from other arthropods but before the divergence of the insects from one another and that the sequences and synteny have been maintained by selection ever since.
Journal Article Availability of antidotes in rural and urban hospitals in Tennessee Get access Peter A. Chyka, Pharm.D., Peter A. Chyka, Pharm.D. Associate Professor of Clinical Pharmacy and Executive Director College of Pharmacy, The Universitsy of Tennessee (UT), Southern Poison Center, Memphis, TN Search for other works by this author on: Oxford Academic Google Scholar Holly G. Conner Holly G. Conner Doctor of pharmacy student UT Search for other works by this author on: Oxford Academic Google Scholar American Journal of Hospital Pharmacy, Volume 51, Issue 10, 15 May 1994, Pages 1346–1348, https://doi.org/10.1093/ajhp/51.10.1346 Published: 15 May 1994
Family farms represent a huge portion of agriculture in the United States today. These family farms may struggle to balance both family relationships and business concerns, which can cause conflict among members. Some of this conflict may be derived from the independent, self-reliant nature of family farmers. These characteristics may influence how family farm members are able to deal with conflict, and how they choose to communicate during conflict interactions. This project used intragroup conflict theory and family communication patterns to explore the impact of everyday conflict on job satisfaction, communication satisfaction, and profitability in family farm businesses. Survey data were collected from family farm members (N = 204). The results of structural equation modeling showed conversation and conformity orientation significantly predicted relational, process, and status conflict in the model, yet only status conflict significantly predicted communication satisfaction. These findings suggested family farm members struggle with communication, which influences status conflict experiences and communication satisfaction.
Hfq is required by many Gram-negative bacteria to chaperone the interaction between small non-coding RNA (sRNA) and mRNA to facilitate annealing. Conversely and despite the presence of Hfq in many Gram-positive bacteria, sRNAs in Gram-positive bacteria bind the mRNA target independent of Hfq. Details provided by the Hfq structures from both Gram-negative and Gram-positive bacteria have demonstrated that despite a conserved global structure of the protein, variations of residues on the binding surfaces of Hfq results in the recognition of different RNA sequences as well as the ability of Hfq to facilitate the annealing of the sRNA to the mRNA target. Additionally, a subset of Gram-negative bacteria has an extended C-terminal Domain (CTD) that has been shown to affect the stability of the Hfq hexamer and increase the rate of release of the annealed sRNA-mRNA product. Here we review the structures of Hfq and biochemical data that have defined the interactions of the Gram-negative and Gram-positive homologues to highlight the similarities and differences in the interactions with RNA. These interactions provided a deeper understanding of the how Hfq functions to facilitate the annealing of sRNA-mRNA, the selectivity of the interactions with RNA, and the role of the CTD of Hfq in the interactions with sRNA.
Abstract: Small non-coding RNAs continue to be identified that regulate the processes of translation and transcription in prokaryotes. A variety of regulatory mechanisms have been characterized by these regulatory RNAs that occur by complementary base pairing between the small regulatory RNA (sreRNA) and a target mRNA, including transcription attenuation, translation inhibition, translation activation, and mRNA protection. Here, we discuss the description of these mechanisms, and the key components that contribute to the interactions between the sreRNA and the target mRNA. Additionally, we classify sreRNAs into categories based on their origins. Antisense RNA (asRNA) is defined strictly as cis-encoded, trans-acting regulatory RNA, while small RNA (sRNA) is strictly defined as trans-encoded, trans-acting regulatory RNA. Although both RNAs bind the target mRNA by Watson-Crick base pairing to the complementary sequence of mRNA, sRNA binding typically requires the presence of a chaperone protein, is only partially complementary to the target mRNA, and often targets multiple mRNAs. Therefore, we characterize the mechanism of sRNA as similar to the well characterized eukaryotic miRNA and discuss the parallels and differences between the two. The binding of asRNA to its target mRNA, by contrast, is typically independent of a chaperone protein, is completely or almost completely complementary to the mRNA target sequence and targets only a single mRNA. While this categorization is likely to evolve as the research identifies more relevant and distinguishing characteristics to classify sreRNAs, the classification used here of prokaryotic sreRNAs should lead to a more refined approach to the discussion and investigation of regulatory RNAs until then.
Abstract Bifidobacteria commonly represent a dominant constituent of human gut microbiomes during infancy, influencing nutrition, immune development, and resistance to infection. Despite interest as a probiotic therapy, predicting the nutritional requirements and health-promoting effects of Bifidobacteria is challenging due to major knowledge gaps. To overcome these deficiencies, we used large-scale genetics to create a compendium of mutant fitness in Bifidobacterium breve ( Bb ). We generated a high density, randomly barcoded transposon insertion pool in Bb , and used this pool to determine Bb fitness requirements during colonization of germ-free mice and chickens with multiple diets and in response to hundreds of in vitro perturbations. To enable mechanistic investigation, we constructed an ordered collection of insertion strains covering 1462 genes. We leveraged these tools to improve models of metabolic pathways, reveal unexpected host- and diet-specific requirements for colonization, and connect the production of immunomodulatory molecules to growth benefits. These resources will greatly reduce the barrier to future investigations of this important beneficial microbe.
In this work, a series of novel boronium-bis(trifluoromethylsulfonyl)imide [TFSI–] ionic liquids (IL) are introduced and investigated. The boronium cations were designed with specific structural motifs that delivered improved electrochemical and physical properties, as evaluated through cyclic voltammetry, broadband dielectric spectroscopy, densitometry, thermogravimetric analysis, and differential scanning calorimetry. Boronium cations, which were appended with N-alkylpyrrolidinium substituents, exhibited superior physicochemical properties, including high conductivity, low viscosity, and electrochemical windows surpassing 6 V. Remarkably, the boronium ionic liquid functionalized with both an ethyl-substituted pyrrolidinium and trimethylamine, [(1-e-pyrr)N111BH2][TFSI], exhibited a 6.3 V window, surpassing previously published boronium-, pyrrolidinium-, and imidazolium-based IL electrolytes. Favorable physical properties and straightforward tunability make boronium ionic liquids promising candidates to replace conventional organic electrolytes for electrochemical applications requiring high voltages.
Here, we investigate the transcriptome profiles of two S. Enteritidis and one S. Schwarzengrund isolates that present different persister levels when exposed to ciprofloxacin or ceftazidime. It was possible to note a distinct transcript profile among isolates, time of exposure, and treatment. We could not find a commonly expressed transcript profile that plays a role in persister formation after S. enterica exposure to beta-lactam or fluoroquinolone, as only three DEGs presented the same behavior under the conditions and isolates tested. It appears that the formation of persisters in S. enterica after exposure to ciprofloxacin is linked to the overexpression of genes involved in the SOS response (recA), cell division inhibitor (sulA), iron-sulfur metabolism (hscA and iscS), and type I TA system (tisB). On the other hand, most genes differentially expressed in S. enterica after exposure to ceftazidime appeared to be downregulated and were part of the flagellar assembly apparatus, citrate cycle (TCA cycle), glycolysis/gluconeogenesis, carbon metabolism, bacterial secretion system, quorum sensing, pyruvate metabolism pathway, and biosynthesis of secondary metabolites. The different transcriptome profiles found in S. enterica persisters induced by ciprofloxacin and ceftazidime suggest that these cells modulate their response differently according to each stress.
The identification of the origin and molecular characteristics of prostate cancer (PCa) has crucial implications for personalized treatment. The development of effective treatments for PCa has been limited; however, the recent establishment of several transgenic mouse lines and/or xenografting models is better reflecting the disease in vivo. With appropriate models, valuable tools for elucidating the functions of specific genes have gone deep into prostate development and carcinogenesis. In the present review, we summarize a number of important PCa research models established in our laboratories (PSA-Cre-ERT2/PTEN transgenic mouse models, AP-OX model, tissue recombination-xenografting models and PDX models), which represent advances of translational models from transgenic mouse lines to human tumor xenografting. Better understanding of the developments of these models will offer new insights into tumor progression and may help explain the functional significance of genetic variations in PCa. Additionally, this understanding could lead to new modes for curing PCa based on their particular biological phenotypes.
BACKGROUND: Conventional near and stereo tests have a "floor effect;" inability to discriminate normal from super-normal. Shotgun champions require unique performance in binocularity and rapid color discrimination. PATIENTS AND METHODS: Twenty-nine champion clay-target shooters, 14 normal Army and 12 color-normal subjects were tested with conventional near vision tests and on PDI-Check, a series of dynamic, near vision tests on the autostereoscopic Nintendo console. RESULTS: Conventional tested shotgunners had all perfect Ishihara and 75% best 40 sec Stereo fly while Army had 92%perfect Ishihara and 69% best stereo fly. On PDI-Check, experienced shotgunners with median stereo of 17 (IQR 12-41) arc sec were better than Army volunteers 59 (IQR 30 to 487) arc seconds (Mann-Whitney U=62, p=0.04). Median PDI-Check for shotgun compared to Army was 88% compared to 84% for blue cone, 90% compared to 84% for green and 77% compared to 72% (red, Mann-Whitney p=0.05). Adding dark cherry filter shooting glasses improved the red and green color detection (p<0.01). This study lacked power to detect eye dominance using PDI Check color or stereo. CONCLUSION: Many champion shotgun shooters had outstanding dynamic near stereo and better-than-average color vision which could be optimized with dark filter spectacles for red and green hues. PDI Check not only helps identify abnormal binocularity and color vision, but it can clarify supranormal vision as well.
Local dynamic heterogeneity in ILs is marked by separation in ion dynamics at nearest neighbor and next-nearest neighbor distances. The separation is temperature and chemical structure dependent and drives polarization across mesoscale aggregates.
(1993). Epic Heroes, Ethical Issues, And Time Paradoxes In Quantum Leap. Journal of Popular Film and Television: Vol. 21, Ethical Issues in Film and Television, pp. 111-120.
In this study, imidazolium-based polymerizable ionic liquids (Poly-ILs) were used to prepare novel polyionic biocomposites through Natural Fiber Welding. Two new Poly-ILs containing a 1-alkyl-3-vinylimidazolium cation and an alkylphosphonate anion were synthesized and evaluated for their ability to (i) solubilize a biopolymer (cellulose) matrix and (ii) polymerize with and without dissolved cellulose. Raman spectroscopy and scanning electron microscopy (SEM) were used to characterize the fiber-welded composites. Optimized fiber-welding parameters yielded polyionic biocomposite materials whose physicochemical properties were evaluated using SEM, energy dispersive X-ray spectroscopy (EDS) and water sorption testing in a controlled relative humidity chamber. SEM/EDS revealed polymerized Poly-IL integrated throughout a fiber-welded, polyionic biocomposite matrix; the materials absorbed ca. 38-40 % of their mass in water when exposed to a controlled (70%) relative humidity environment. To reduce the hygroscopic nature of the fiber-welded composites, the methylphosphonate anion was partially exchanged for a more hydrophobic anion (bis-trifluorosufonylimide, TFSI) through a single-pass anion exchange. SEM/EDS of sample cross sections before and after treatment show that this simple anion exchange and rinse procedure delivers up to ca. 5% exchange from methylphosphonate to TFSI. In spite of this low exchange, the water sorption properties of the exchanged polyionic biocomposites were successfully reduced by 14% and could be easily returned to their original dry state at low temperature under vacuum.
Considered in the context of contemporary, upper-class mourning practices on the British home front, Lady Alda Hoare’s annotated sheet music collection symbolized a shrine to her son, who was killed in the First World War. Such use of material objects as sources of consolation became substitutes for the normal ritual of a burial, since soldiers’ bodies were not sent home. Departing from the existing literature’s focus on the public and professional musical responses to the War, Lady Alda’s music reveals an alternative, intensely private way in which music, as a symbol of memory, aided in the grieving process.
Echinometra spp. are pantropical echinoids found in benthic marine habitat throughout the Caribbean, Atlantic, and Indo-West Pacific oceanic regions. Currently, morphology and molecular data are sparse for echinoids observed along the northeastern coast of Toco, Trinidad, where they are relatively common. Additionally, accurate species identity for Echinometra spp. remains dynamic at both northernmost and southernmost parts of the Caribbean Sea. Although distribution of sea urchins in the genus Echinometra have extensively been studied throughout the Atlantic and Indo-West Pacific, information on its range of distribution at the edge of the Caribbean Sea is lacking. In this study, the mitochondrial Cytochrome c Oxidase subunit I (mt COI) gene was amplified using polymerase chain reaction, then sequenced. Based on successfully obtained gene sequences for 581 base pairs, the echinoid species Echinometra lucunter and Echinometra viridis were identified for black and red color morphotypes from Trinidad (n = 23) and Key Largo, Florida (n = 6), respectively. Furthermore, these specimens were genetically identical to species identified in other studies for Puerto Rico, Panamá, Honduras, and Belize. Although morphological variations, such as spine and test color occur throughout Echinometra spp., molecular identification using the barcoding technique confirmed E. lucunter color morphs for the first time in Trinidad. Since the status of E. lucunter populations, specifically at the most northern and southern regions of the Caribbean Sea is dynamic, further studies using gene markers are essential in determining species distribution, in light of current trends in climate change.
Zoantharians are colonial cnidarians commonly found in shallow tropical Caribbean coral reefs, and are known to be globally distributed. Common species in genera Zoanthus and Palythoa occur at Toco, Trinidad, where they are more abundant than their Scleractinia counterparts relative to benthic coverage. In this study, distribution, morphological and molecular data were collected to determine species and symbiont identification to provide more insight on zoantharians. The Line Intercept Point (LIT) transect method recorded coverage at three sites: Salybia (SB), Pequelle (PB), and Grande L’Anse (GA) Bays along the northeastern coast. Variations in morphology, such as tentacle count, oral disk color and diameter were collected from colonies in situ. All specimens were zooxanthellate, and molecular and phylogenetic analyses were done by sequencing the cytochrome oxidase subunit I (COI) gene, and the internal transcribed spacer (ITS) region for species and symbiont identification, respectively. Results showed mean Zoantharia percentage cover was 32.4% ± 5.1 (X ± SE) at SB, 51.3% ± 6.5 (PB), and 72.2% ± 6.1 at GA. Zooxanthellate zoantharians were identified as Palythoa caribaeorum, Palythoa grandiflora, Zoanthus pulchellus, and Zoanthus sociatus. Symbiodiniaceae genera were identified as Cladocopium and Symbiodinium in Palythoa and Zoanthus spp., respectively. Although this is the first molecular examination of zoantharians, and their symbionts in Trinidad, more research is needed to identify and document species distribution and symbiont biodiversity to understand their ecology in these dynamic ecosystems.
Ion dynamics and charge transport in a homologous series of imidazolium chloroaluminate ionic liquids are investigated by broadband dielectric spectroscopy, rheology, viscometry, and differential scanning calorimetry. The interplay of anion speciation and alkyl chain length on local and mesoscale dynamics and the corresponding influence on the dc ionic conductivities, zero-shear viscosities, and static dielectric permittivities is investigated. These results are presented within a broader framework of current understanding of dynamics and transport properties of aprotic ionic liquids.
Ion dynamics and transport properties of the ionic liquid 1-methyl-3-decylimidazolium chloride are investigated by broadband dielectric spectroscopy, shear rheology, and differential scanning calorimetry. This ionic liquid is known to undergo a low-temperature, liquid-liquid crystal (L-LC) phase transition previously associated with a transition or growth in the extent of mesoscale solvophobic aggregates. We find that the L-LC transition is accompanied by a significant change in both the timescale and the strength of dielectric and mechanical relaxation processes associated with the motions of the mesoscale solvophobic aggregates. However, no change is observed in faster, more-localized ion motions associated with ion diffusion. Due exclusively to the changes in the slow, supramolecular dynamics, the zero-shear viscosity of the ionic liquid is increased fivefold, while the ionic conductivity is unaffected. These results provide unique insight into the role of mesoscale solvophobic structure on the transport properties of ionic liquids, indicating that the supramolecular mesoscale solvophobic aggregates may, at times, have a sizable influence on the zero-shear viscosities while having a negligible influence on ion conduction, which is determined exclusively by the faster diffusive ion motions occurring at shorter length-scales.
ABSTRACT Salmonellosis and shigellosis remain major global health concerns, with Salmonella Typhimurium and Shigella flexneri classified as high-priority antibiotic-resistant pathogens by the World Health Organization. The development of new antibiotics is slow and challenging, underscoring the need for alternative therapeutic strategies. One promising approach involves leveraging gut microbiota-derived bacteria that confer colonization resistance against enteric pathogens. In this study, we screened a human gut microbiota culture collection and identified Bifidobacterium longum as the most effective species in inhibiting S . Typhimurium and S. flexneri in vitro . To evaluate its protective potential in vivo , we utilized Caenorhabditis elegans as a model system. Our findings demonstrate that B. longum significantly reduced pathogen burden and enhanced host survival following infection. Mechanistic analysis revealed that B. longum inhibits S . Typhimurium primarily through acidification, while S. flexneri suppression appears to involve a protein-mediated or heat-stable metabolite-dependent mechanism. Additionally, B. longum modulated host immune pathways, downregulating genes associated with the p38 MAPK and insulin/IGF-1 signaling pathways. These results highlight the potential of B. longum as a non-antibiotic therapeutic for controlling Salmonella and Shigella infections. However, further validation in mammalian models is required to assess its clinical relevance. IMPORTANCE Gut infections caused by Salmonella and Shigella are major global health threats. As an alternative to novel drug discovery, which is time-consuming and faces several challenges, this study explores the potential of gut bacteria to protect against these pathogens. We identified Bifidobacterium longum , a common gut microbe, which can significantly reduce infection by both Salmonella and Shigella in a lab setting and in a simple animal model. The bacterium functions by creating an environment that is hostile to pathogens and by modulating the host’s immune responses. These findings suggest that B. longum could be developed as a natural, non-antibiotic treatment to control or reduce these enteric pathogen infections. This approach opens the door to using probiotics as effective tools in the global fight against antibiotic resistance.