NaAtm1: Examining the mechanism of a Heavy-metal ABC Exporter

ATP-Binding Cassette (ABC) Transporters are a superfamily of integral membrane proteins that have been found embedded in both the cellular membranes and internal organelles of all species yet analyzed (1). This extreme conservation throughout the tree of life is due to their vitally critical and broad task of transporting all manner of things into and out of the cell and related organelles. This broadness of responsibility has led to an abundant diversity of this family, which in turn, has allowed life to adapt to the many environments found on Earth. While the importance and variability of this family is abundantly clear, many mechanistic and regulatory questions remain. The diversity which has made this family so useful in the natural world has resulted in a huge challenge in the scientific world: elucidating the many mechanisms this family has developed to perform its many functions. The scientific community has so far been able to identify overarching features of all ABC transporters such as the Walker A and Walker B motifs (1); however, the mechanisms of individual transporters remain undiscovered. In my research, I focus on a specific ABC transporter called NaAtm1 (Novosphingobium aromaticivorans ABC transporter of mitochondria 1), which has been shown to mediate transition metal export in its host species (2). While some transition metals (e.g. iron and copper) are essential for certain cellular processes such as respiration and enzyme catalysis, other metals (e.g. cadmium and mercury) can be very toxic. Due to this extreme dichotomy, a cell’s ability to distinguish between friend and foe is of the utmost importance, and therefore is a highly regulated process. My goal during this program was to purify NaAtm1 and create a realistic in-vitro environment to analyze and better understand the full mechanism of this transporter, to determine why it exports some metals while leaving others alone, and to understand the regulatory processes that control it. References [1] Davidson, A. L.; Dassa, E.; Orelle, C.; Chen, J. Structure, function, and evolution of bacterial ATP-binding cassette systems. Microbiology and Molecular Biology Reviews 2008, 72(2), 317–364. [2] Lee, J. Y.; Yang, J. G.; Zhitnitsky, D.; Lewinson, O.; Rees, D. C. Structural basis for heavy metal detoxification by an Atm1-type ABC exporter. Science 2014, 343(6175), 1133–1

Health Behavior Patterns Among First-Year and Non-first-Year College Students Attending a North Carolina Historically Black University

The major purpose of this study was to conduct a baseline investigation of self-rated health behavior and quality of life among first-year and non-first-year college students. The authors used a quality of life questionnaire that was designed to gauge college students\u27 health status, lifestyle, mental health, and living conditions. Results from this study indicated that there were significant differences among health behavior patterns between first-year and non-first-year college students. Most importantly, this study provides compelling information regarding the physical and psychological health behaviors among a mostly African American student population who attended a historically Black university in North Carolina. Implications for university student personnel, counselors, andfaculty are discussed

Spirituality Among a Predominately African American College Student Population

The purpose of this study was to determine the degree of spirituality among 430 predominately African American undergraduate students who completed the 48-item Life Attitude Profile-Revised (LAP-R). T-tests revealed that these students had a higher spirituality score than their predominately White counterparts who recently completed the LAP-R. Unlike the White students, no significant gender differences were found among specific spiritual indices. If these students use their moderately high degree of spirituality to influence health-related behaviors, the high rates of morbidity and mortality common among African American adults may lessen

Examining Differences in Middle School Student Achievement on a State Mandated Examination: Does a Full Year of Agriscience Really Make a Difference?

Early agricultural education programs in the United States existed to promote new methods and techniques to further agricultural production. Today, extending integration, general knowledge, appreciation, and literacy about agriculture is the goal, especially at the middle school level. Not only is agricultural education designed to encompass academics, but science and technology, literacy, and career preparedness are parts of the total agricultural education program. Since the passage of No Child Left Behind Act (NCLB), more pressure has been put on teachers to generate increased student academic performance and improvement of test scores. The purpose of this research study was to determine if there were statistically significant differences in academic achievement on a state mandated assessment of students who completed a yearlong middle school agricultural education course and students who completed only an eight week middle school agricultural education course in the same school, with the same instructor; the significance in time spent in the course was the main issue in question. The findings showed a statistically significant relationship between the completion of the year-long agricultural education course and math, science, and social studies scores on the state mandated assessment. For example, both 7th and 8th grade students who completed a year-long brain-based agricultural education course had higher mean scores than students who completed only an eight-week brain-based agricultural education course on the math, science, and social studies portions of the assessment

Asset-Building in Tribal Communities: Generating Native Discussion and Practical Approaches

Asset-Building in Tribal Communities: Generating Native Discussion and Practical Approache

Examining the Bacterial Methionine Transporter Utilizing Soluble Lipid Bilayer Systems

The phospholipid bilayer present in both eukaryotes and prokaryotes regulates the cell’s acquisition of nutrients and excretion of waste. Studies on the complex components of the lipid bilayer have paved the way for learning about the selective permeability of the membrane. It is of great interest to understand how materials are being transported through transmembrane proteins in relation to the electrochemical gradient. Investigation into the mechanistic properties of these transport proteins, particularly ATP-binding cassettes (ABC) transporters, can clarify how substrates are being transported via the binding and hydrolysis of adenosine triphosphate (ATP). The study of ABC transporters is significant in human disease treatment; for example, the alteration of the ATP transport protein domain has been found to lead to multidrug-resistance (Boumendjel, A., 2009) and cystic fibrosis (Mendoza, J., 2007). The overall goal of this project is to compare the activity of the MetNI transporter, a methionine importer, solubilized in detergent to the activity in nanodiscs, a self-contained lipidic environment (Sligar, 2008). First, the membrane-scaffolding protein (MSP) component of nanodiscs MSP3 was successfully bacterially expressed in E. coli cells on a large-scale and then purified by fast protein liquid chromatography (FPLC). Preliminary ATPase assays were conducted on detergent-solubilized MetNI. We calculated that the MetNI transporter isolated in detergent has an average Km of 619 µM and kcat of 4.3 min-1. The comparison of the MetNI ATPase rate in lipidic versus detergent environments will be carried out once MetNI is successfully reconstituted into nanodiscs

FLEX: A Decisive Step Forward in NASA's Combustion Research Program

Stemming from the need to prevent, detect and suppress on-board spacecraft fires, the NASA microgravity combustion research program has grown to include fundamental research. From early experiment, we have known that flames behave differently in microgravity, and this environment would provide an ideal laboratory for refining many of the long held principals of combustion science. A microgravity environment can provide direct observation of phenomena that cannot be observed on Earth. Through the years, from precursor work performed in drop towers leading to experiments on the International Space Station (ISS), discoveries have been made about the nature of combustion in low gravity environments. These discoveries have uncovered new phenomena and shed a light on many of the fundamental phenomena that drive combustion processes. This paper discusses the NASA microgravity combustion research program taking place in the ISS Combustion Integrated Rack, its various current and planned experiments, and the early results from the Flame Extinguishment (FLEX) Experiment

Case report: MELAS and concomitant presumed antiphospholipid antibody syndrome in an adult woman

Mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes, and other features (short stature, headaches, seizures, and sensorineural hearing loss) constitute characteristics of MELAS syndrome. MELAS is a rare condition due to mutations in maternally inherited mitochondrial DNA with levels of heteroplasmy possibly related to late adulthood presentation. A previously reported MELAS case coexisted with presumed Antiphospholipid Antibody Syndrome (APLAS), but the connection between MELAS and a potential APLAS is unclear. A 29-year-old woman presented with mild right-sided sensorimotor symptoms and mixed aphasia in November 2021. She presented again in May 2022 for unrelenting headaches and was found to have a new right hemisphere syndrome with mild left-sided sensorimotor symptoms, hemineglect, and anosognosia. Characteristic lab and imaging studies were obtained. During the first presentation (October 2021), the discovery of anticardiolipin IgM antibodies (aCL) (and their replication 3 months later) led to a diagnosis of APLAS, and Warfarin was initiated. During the second admission (May 2022), a new stroke-like lesion on the right hemisphere with characteristic features not suggestive of ischemia was detected, which led to a diagnosis of MELAS (m3243A > G mutation). Although MELAS and APLAS could co-exist, alternatively, it is possible that antiphospholipid antibodies might be generated when the strongly anionic Cardiolipin-Hydroperoxide from the inner mitochondrial membrane is exposed to immune component cells upon cell lysis. Thus, the presence of aCL in patients with stroke-like lesions might masquerade as an APLAS, but should probably be questioned if only aCL are repeatedly found and imaging findings are not characteristic for ischemic lesions

Cost and performance analysis of physical security systems

CPA - Cost and Performance Analysis - is a prototype integration of existing PC-based cost and performance analysis tools: ACEIT (Automated Cost Estimating Integrated Tools) and ASSESS (Analytic System and Software for Evaluating Safeguards and Security). ACE is an existing DOD PC-based tool that supports cost analysis over the full life cycle of a system; that is, the cost to procure, operate, maintain and retire the system and all of its components. ASSESS is an existing DOE PC-based tool for analysis of performance of physical protection systems. Through CPA, the cost and performance data are collected into Excel workbooks, making the data readily available to analysts and decision makers in both tabular and graphical formats and at both the system and subsystem levels. The structure of the cost spreadsheets incorporates an activity-based approach to cost estimation. Activity-based costing (ABC) is an accounting philosophy used by industry to trace direct and indirect costs to the products or services of a business unit. By tracing costs through security sensors and procedures and then mapping the contributions of the various sensors and procedures to system effectiveness, the CPA architecture can provide security managers with information critical for both operational and strategic decisions. The architecture, features and applications of the CPA prototype are presented. 5 refs., 3 figs