UARK (University of Arkansas )
Not a member yet
19829 research outputs found
Sort by
Optimizing Recombinant Cas9 Expression: Insights from \u3ci\u3eE. coli\u3c/i\u3e BL21(DE3) Strains for Enhanced Protein Purification and Genome Editing
Get PDFThe CRISPR-Cas9 system is a revolutionary tool in genetic engineering, offering unprecedented precision and efficiency in genome editing. Cas9, an enzyme derived from bacteria, is guided by RNA to edit DNA sequences within cells precisely. However, while CRISPR-Cas9 presents notable benefits and encouraging outcomes as a molecular tool and a potential therapeutic agent, the process of producing and purifying recombinant Cas9 protein remains a formidable hurdle. In this study, we systematically investigated the expression of recombinant SpCas9-His in four distinct Escherichia coli (E. coli) strains (Rosetta2, BL21(DE3), BL21(DE3)-pLysS, and BL21(DE3)-Star). Through optimization of culture conditions, including temperature and post-induction time, the BL21(DE3)-pLysS strain demonstrated efficient SpCas9 protein expression. This study also presents a detailed protocol for the purification of recombinant SpCas9, along with detailed troubleshooting tips. Results indicate successful SpCas9 protein expression using E. coli BL21(DE3)-pLysS at 0.5 mM IPTG concentration. Furthermore, the findings suggest potential avenues for further enhancements, paving the way for large-scale Cas9 production. This research contributes valuable insights into optimizing E. coli strains and culture conditions for enhanced Cas9 expression, offering a step forward in the development of efficient genome editing tools and therapeutic proteins
Twenty-five Years of Award-winning Education Publication Excellence in ASHS Journals
Get PDFThe American Society for Horticultural Science Education Publication Excellence award was established in 1997 to recognize the most outstanding publication in ASHS journals related to education and teaching. This article reviews the award history, authors, and topics of the awarded papers. The award was recognized annually from 1998 to 2023 except for 3 years when no award was given. The majority of awarded papers were published in HortTechnology. Awards were presented to 70 authors from 23 institutions in 20 states and two other countries. Of the awarded papers, three had single authors, and 20 had multiple authors. Several awarded authors have been recognized in other ASHS publication awards or professional career awards. The majority of awarded papers focused on undergraduate students, teaching methods, and floriculture or ornamental topics
Tolerance of Young Blackberries to a Selection of Preemergence Herbicides and Rates
Get PDFLimited preemergence herbicides are registered for new blackberry (Rubus subgenus Rubus) plantings. This greenhouse experiment was designed to investigate the effects of a broad selection of preemergence herbicides at multiple rates on blackberry transplants. Screening was initiated Aug 2021 and repeated Mar 2022 in Fayetteville, AR, USA, in a greenhouse at the Milo J. Shult Agricultural Research and Extension Center. ‘Ouachita’ blackberry plugs were transplanted into utility pots that contained field soil and growth media treated with preemergence herbicides. After transplanting, plant height was measured from the substrate to the highest apical meristem of 25 representative plants. Initial blackberry plant heights were 13.5 and 9.2 cm in 2021 and 2022, respectively. Twenty-five treatments were evaluated, consisting of 12 preemergence herbicides at 1× and 2× field rates, and one untreated control. Herbicide treatments included diuron, flumioxazin, halosulfuron, indaziflam, mesotrione, napropamide, oryzalin, pendimethalin, rimsulfuron, S-metolachlor, simazine, and sulfentrazone applied to substrate in containers at their respective 1× or 2× field rates. Data were collected on plant height, blackberry injury ratings, internode length, leaf chlorophyll content, and destructive harvest, including leaf count, leaf dry biomass, and aboveground dry biomass. Specific leaf areas and leaf area-to-dry matter ratios were calculated. When observed, plant injury tended to increase from 7 days after treatment (DAT) until 42 DAT. Greater injury levels were observed in response to treatment with mesotrione at the 1× (78%) and 2× rates (90%), halosulfuron at the 1× rate (58%), halosulfuron at the 2× rate (68%), and diuron at the 2× rate (73%). Injury from diuron was rate dependent, with the 1× rate causing relatively low injury (19%). At both the 1× and 2× rates, flumioxazin, indaziflam, napropamide, S-metolachlor, and pendimethalin treatments exhibited similar responses to the untreated control
The Bacterial Cell Wall Components Lipopolysaccharide and Peptidoglycan Initiate Divergent Local Tissue and Systemic Inflammatory Response Profiles in the Chicken Model
Get PDFThe innate immune system plays an important role in the early defense against pathogens. To better understand the chicken’s innate inflammatory responses, we concurrently examined the cellular responses at the injection site and in the blood following intradermal (i.d.) injections of lipopolysaccharide (LPS) or peptidoglycan (PGN) into the pulp of growing feathers (GFs). Both LPS from Gram-negative bacteria and PGN from Gram-positive bacteria are potent stimulators of innate inflammatory responses. The time-course study conducted revealed similarly elevated levels of heterophils and macrophages in injected GF-pulps during the first 24 h for both LPS and PGN. However, PGN also stimulated rapid infiltration of lymphocytes, with high levels sustained for 7 days post-injection. The i.d. injection of LPS also affected leukocyte profiles in the blood, whereas PGN did not. Overall, the temporal, qualitative, and quantitative differences in the inflammatory responses to LPS and PGN suggest different innate immune response mechanisms in the defense against infection with Gram-negative and Gram-positive bacteria in chickens
LCA Operational Carbon Reduction Based on Energy Strategies Analysis in a Mass Timber Building
Get PDFBuildings play a significant role in the rise of energy consumption and carbon emissions. Building operations are responsible for 28% of the world’s carbon emissions. It is crucial, therefore, to evaluate the environmental impact of various buildings’ operational phase in order to implement sustainable strategies for the mitigation of their energy usage and associated carbon footprint. While numerous studies have been conducted to determine the carbon footprint of conventional building operation phases, there are still a lack of actual data on the operational carbon (OC) emissions of mass timber buildings. There is also a lack of research pertaining to the operational carbon of buildings within larger campuses and their inherent energy usage. This study, therefore, aims to quantify empirical data on the carbon footprint of a mass timber building, using, as a case study, the recent Adohi Hall building, situated at the University of Arkansas, Fayetteville. The study also aims to examine and identify the best energy use scenarios for the campus building under consideration. The research team obtained data on Adohi Hall’s energy consumption, fuel input usage, and other utilities (such as water, electricity, chilled water, and natural gas) accounting for the operation of the building from 2021 to 2023, a span of three years. The University of Arkansas Facilities Management (FAMA) provided the data. The study relies on the life cycle assessment (LCA) as its primary approach, with SimaPro 9, Ecoinvent v3.7 database, DataSmart, version 2023.1 and the U.S. Life Cycle Inventory (USLCI) database utilized to model the energy and water consumption of Adohi Hall during the operational phase (B6 & B7). The results indicate 4496 kg CO2 eq emissions associated with the operation per square meter of Adohi Hall over its 50-year lifespan. The study also examines various scenarios of fuel sources leading to carbon emissions and provides insights into reduction strategies during the operational phase of buildings. Among them, the electricity based on a cleaner fuel source diversification, according to realistic expectations and technological advancements projections, results in a 17% reduction in Adohi Hall’s OC. Due to the usage of the combined heat and power (CHP) plant on the campus of the University of Arkansas as a complementary source of electricity and heating for Adohi Hall, the resulting carbon emission is approximately 21% (20.73%) less when compared to similar buildings in the same city but outside the campus. The study, therefore, reveals that CHP plant development is a highly effective strategy for building OC reduction
Recovery of Ionic Liquid from the Model Solution Mixture Mimicking the Catalytically Hydrolyzed Cellulose Product Utilizing Amberlyst Ion-Exchange Resin
Get PDFThe hydrolysis of cellulose using ionic liquid (IL) has been extensively studied but there is limited understanding of the removal of IL from the biomass hydrolysate. Finding a suitable method for the recovery and reuse of IL is one of the biggest challenges before its large-scale application. Selecting an appropriate combined recovery process is very important. This study proposed a facile ion-exchange combined method for the recovery of IL from the modeled cellulose hydrolysate mixture containing sugars as well as γ-valerolactone (GVL) via an adsorption–desorption mechanism using sulfonic acid cation-exchange (Amberlyst 15 (H)) resin. The results showed that the resin could adsorb more than 94% of 1-ethyl-3-methylimidazolium chloride [Emim]Cl IL at ambient conditions within a contact time of 20 min. The other coexisting constituents like glucose and GVL have no significant effect on the adsorption efficiency of IL. The adsorption of IL on Amberlyst 15 (H) resin was observed to be pseudo-second-order adsorption. The regeneration of the adsorbed IL was possible up to 70% using low-cost, easily available sodium chloride (NaCl) solution. Similarly, despite the interference of other unwanted byproducts in the real biomass hydrolysate sample, an IL adsorption efficiency up to 51% was reached under similar operating conditions. This study thus opens the facile possibility of extracting and recycling IL used in the biomass hydrolysis process
Evaluation of Industrial Hemp Cultivar and Biochar Rate to Remediate Heavy-Metal-Contaminated Soil from the Tar Creek Superfund Site, USA
Get PDFSoil contamination by cadmium (Cd), lead (Pb), and zinc (Zn) at the Tar Creek superfund site in northeast Oklahoma, United States, remains a threat to the environment and local ecosystem. Phytoremediation with industrial hemp (Cannabis sativa L.) and the use of biochar (BC) have been independently shown to be effective methods to remediate heavy-metal-contaminated soils. The objective of this greenhouse study was to evaluate the effects of industrial hemp cultivar (‘Carmagnola’ and ‘Jinma’), biochar rate (0, 2, 5, and 10% by volume), soil contamination level (low, medium, and high), and their interactions on above- (AG) and belowground dry matter (DM) and AG tissue concentrations, as well as uptakes of Cd, Pb, and Zn after 90 days of growth in naturally contaminated soils from the Tar Creek superfund site. Aboveground DM was the largest (p \u3c 0.01) in the low- (0.06 g cm−2) and smallest in the high-contaminated soil (0.03 g cm−2), and was unaffected (p \u3e 0.05) by cultivar or BC rate. Averaged across BC rates, AG tissue Pb and Zn concentrations from the high-’Carmagnola’ and -’Jinma’ combinations were at least 2.4 times greater than from the other four soil–cultivar combinations. Averaged across cultivars, AG tissue Pb uptake in the high-5 and high-10% BC combinations were at least 2.7 times greater than in the high-0 and high-5% BC combinations, which did not differ. The results indicated that both ‘Carmagnola’ and ‘Jinma’ may be suitable choices for phytoremediation of mixed Cd-, Pb-, and Zn-contaminated soil when grown in combination with 5 or 10% (v/v) BC
Target-site Mutations Ile1781Leu and Ile2041Asn in the \u3ci\u3eACCase2\u3c/i\u3e Gene Confer Resistance to Fluazifop-p-butyl and Pinoxaden Herbicides in a Johnsongrass Accession from Arkansas, USA
Get PDFJohnsongrass [Sorghum halepense (L.) Pers.] is a troublesome weed species in different agricultural and non-agricultural areas. Because of its biology, reproductive system, and seed production, effective management is challenging. An accession with low susceptibility to the acetyl-CoA carboxylase (ACCase)-inhibiting herbicides fluazifop-p-butyl (fluazifop) and pinoxaden was collected in eastern Arkansas. In this research, the molecular mechanisms responsible for ACCase resistance were investigated. Dose–response experiments showed a resistance factor of 181 and 133 for fluazifop and pinoxaden, respectively. Molecular analysis of both ACCase1 and ACCase2 genes was researched. Nucleotide comparison of ACCase1 between resistant and susceptible accessions showed no single nucleotide polymorphisms. Nonetheless, analysis of ACCase2 in fluazifop-resistant johnsongrass plants revealed the Ile1781Leu target-site mutation was dominant (nearly 75%), whereas the majority of pinoxaden-resistant johnsongrass plants had the Ile2041Asn (60%). Not all sequenced johnsongrass plants displayed a target-site mutation, suggesting the presence of additional resistance mechanisms. Amplification of ACCase1 and ACCase2 was not responsible for resistance because of the similar values obtained in both resistant and susceptible accessions. Experiments with malathion and NBD-Cl suggest the presence of herbicide metabolism. Outcomes of this research demonstrated that fluazifop- and pinoxaden-resistant johnsongrass plants displayed a target-site mutation in ACCase2, but also that non-target-site resistance mechanisms would be involved and require a detailed study
Catchment-scale Thawing and Greening Decreases Long-term Nitrogen Export in NE Greenland
Get PDFClimate change is expected to alter nitrogen (N) export from Arctic rivers, with potential implications for fragile coastal ecosystems and fisheries. Yet, the directionality of change is poorly understood, as increased mobilization of N in a \u27thawing\u27 Arctic is countered by higher rates of vegetative uptake in a \u27greening\u27 Arctic, particularly in the understudied region of Greenland. We use an unprecedented dataset of long-term (n = 18 years) river chemistry, streamflow, and catchment-scale changes in snow and vegetation to document changing riverine N loss in Greenland. We documented decreasing inorganic and organic N loads, linked to decreasing snow stores, warming soils, and enhanced plant uptake. Higher variability in N export across years also points to the increasing role of high flow events in driving downstream N loss. This alteration in N cycling may significantly reduce both inorganic and organic N transport across the terrestrial-aquatic boundary during the open water season in a rapidly warming Greenland
Sulfites and Sulfates Formed by Weathering of Early Martian Carbonates in a Sulfur Dioxide-Bearing Atmosphere
Get PDFDespite ample evidence that extensive water–rock interactions occurred under a CO2-dominated atmosphere on early Mars, carbonate minerals are relatively rare at the surface. One possibility to explain this scarcity is that carbonates were initially abundant, but were later destroyed when atmospheric conditions changed, particularly as a result of volcanism releasing large volumes of sulfur dioxide SO2 into the atmosphere. However, despite some early theoretical and experimental results, no study has investigated the stability of the most common carbonates (Ca, Mg and Fe) in the presence of abundant SO2 gas. Here we present the results of experiments demonstrating that carbonates are systematically unstable when exposed to 0.8 bar of SO2 in moderately oxidizing (SO2 + H2O) or strongly oxidizing (SO2 + H2O + H2O2) environments. In both environments, the reaction end products are systematically sulfates, except for calcium carbonate, which predominantly transforms into calcium sulfite (hannebachite) in moderately oxidizing conditions. Based on these results, carbonates formed early in martian history would have been rapidly decomposed and replaced by sulfates (and sulfites if calcium was abundant enough) in the presence of abundant SO2 released by major volcanic events such as those associated with the build-up of the Tharsis rise