University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

Continuous directed evolution of aminoacyl-tRNA synthetases

Abstract: Directed evolution of orthogonal aminoacyl-tRNA synthetases (AARSs) enables site-specific installation of noncanonical amino acids (ncAAs) into proteins. Traditional evolution techniques typically produce AARSs with greatly reduced activity and selectivity compared to their wild-type counterparts. We designed phage-assisted continuous evolution (PACE) selections to rapidly produce highly active and selective orthogonal AARSs through hundreds of generations of evolution. PACE of a chimeric Methanosarcina spp. pyrrolysyl-tRNA synthetase (PylRS) improved its enzymatic efficiency (kcat/KMtRNA) 45-fold compared to the parent enzyme. Transplantation of the evolved mutations into other PylRS-derived synthetases improved yields of proteins containing noncanonical residues up to 9.7-fold. Simultaneous positive and negative selection PACE over 48 h greatly improved the selectivity of a promiscuous Methanocaldococcus jannaschii tyrosyl-tRNA synthetase variant for site-specific incorporation of p-iodo-L-phenylalanine. These findings offer new AARSs that increase the utility of orthogonal translation systems and establish the capability of PACE to efficiently evolve orthogonal AARSs with high activity and amino acid specificity.

An Empirical Classification of Motivations for Domestic Violence

Abstract: National survey research suggests that males and females are equally likely to perpetrate domestic violence, but surveys have not examined the interpersonal context or motivation for domestic violence. The questioning of identified partner assaulters suggests that females use violence for self-defense and escape, whereas males use violence to exercise control, punish, or demand attention. The perception of perpetrator violence, however, appears also to be a function of the gender of the individual appraising the violence. Six male and 6 female adult nonperpetrators sorted into categories the stated motivations for domestic violence of 215 male and 66 female court-referred perpetrators. Factor analysis revealed (a) motivations common to all: control, anger expression, and coercive communication; (b) motivations specific to gender of perpetrator: retaliation, self-defense, escape, and punishment; and (c) motivations specific to gender of perpetrator and sorter: alcohol use and response to verbal abuse.

The Psychological Science Accelerator: Advancing Psychology through a Distributed Collaborative Network

Abstract: Concerns about the veracity of psychological research have been growing. Many findings in psychological science are based on studies with insufficient statistical power and nonrepresentative samples, or may otherwise be limited to specific, ungeneralizable settings or populations. Crowdsourced research, a type of large-scale collaboration in which one or more research projects are conducted across multiple lab sites, offers a pragmatic solution to these and other current methodological challenges. The Psychological Science Accelerator (PSA) is a distributed network of laboratories designed to enable and support crowdsourced research projects. These projects can focus on novel research questions or replicate prior research in large, diverse samples. The PSA’s mission is to accelerate the accumulation of reliable and generalizable evidence in psychological science. Here, we describe the background, structure, principles, procedures, benefits, and challenges of the PSA. In contrast to other crowdsourced research networks, the PSA is ongoing (as opposed to time limited), efficient (in that structures and principles are reused for different projects), decentralized, diverse (in both subjects and researchers), and inclusive (of proposals, contributions, and other relevant input from anyone inside or outside the network). The PSA and other approaches to crowdsourced psychological science will advance understanding of mental processes and behaviors by enabling rigorous research and systematic examination of its generalizability.

A review of practical Salmonella control measures in animal feed

Abstract: SUMMARY Salmonella is a major microbial hazard in animal feed. Salmonella can persist for long periods in a wide range of materials. The lack of uniformity involved in Salmonella contamination and the large volumes of feed produced make accurate assessments of feed contamination rates difficult. Salmonella control principles may be divided into 3 broad categories: efforts to prevent contamination from entering the facility, work to reduce microbial multiplication within the plant, and procedures designed to kill the pathogen. Preventing contamination also involves controlling dust, managing the flow of equipment and humans, reducing rodent infestations, preventing contamination from wild birds, and ensuring the sanitation of transport vehicles. Reducing Salmonella multiplication in feed manufacturing facilities involves discovering microbial growth niches and reducing conditions that lead to growth. Killing Salmonella may involve thermal processing (pelleting) or chemical addition. Pelleting reduces, but may not completely eliminate, Salmonella contamination because of limitations of the process or recontamination after thermal processing. Chemical additions to control Salmonella in feed primarily involve the use of products containing organic acid, formaldehyde, or a combination of such compounds.

3D Social Virtual Worlds: Research Issues and Challenges

Abstract: Today's social virtual worlds (SVW) are beginning to realize Stephenson's vision of the metaverse: a future massive network of interconnected digital worlds. Tens of millions of people already use these kinds of environments to communicate, collaborate, and do business. Big companies are also moving into these digital realms. Thus, in a context in which the Web is becoming increasingly social, we believe that SVWs are beginning to shape the knowledge-based and glo balized societies and economies of tomorrow. Obviously, an urgent need exists to further understand SVWs and their implications for theory and practice. This article constitutes a first attempt to bring researchers into some of the business, social, technical, legal, and ethical issues related to SVWs. We anticipate that researchers will need to build new theories and concepts for SVWs, to explore the frontiers between reality and virtuality.