bluuebunny/crossref_metadata_2025_split huggingface dataset:
Varied Effects of Dietary Carotenoid Supplementation on Oxidative Damage in Tissues of Two Waterfowl Species
Authors: Mohr Alex E , Girard Marc , Rowe Melissah , McGraw Kevin J , Sweazea Karen L 
Published: June 2021

The antioxidant potential of dietary carotenoids is widely debated for birds, with some studies supporting a protective role whereas others report either no effect or even a pro‐oxidant effect. However, the majority of previous research on this topic has not analyzed the oxidative status of a series of tissues in animals and has not considered a range of carotenoid dosages. Therefore, we investigated the effects of three levels of dietary carotenoid supplementation on plasma, liver, adipose, heart, and breast muscle oxidative damage in two congeneric species of ducks. After a 6‐week depletion period, captive adult northern pintail (Anas acuta) and mallard (A. platyrhynchos) ducks of both sexes were fed either a carotenoid‐depleted diet (<3 μg/g), a carotenoid‐rich diet (50 μg/g) within physiological range, or a carotenoid‐rich diet (100 μg/g xanthophylls) within pharmacological range for 17 weeks. We hypothesized that this range of dietary carotenoid dosages would differently affect oxidative damage, as measured by thiobarbituric acid reactive substances (TBARS), between species and sexes and among the tissues examined. Overall, liver and heart tissue exhibited the highest levels of oxidative damage, whereas adipose tissue had the lowest. We found that dietary xanthophyll (lutein and zeaxanthin) supplementation had no significant effect on tissue pro‐oxidation in males and females from both species. Moreover, for only two tissues (plasma and heart) did we find sex or species differences in oxidative stress. We did not find significant correlations in the levels of oxidative damage among plasma, liver, adipose, heart and breast muscle. In conclusion, the current study does not support a consistent antioxidant role for dietary carotenoids in the tissues of these two waterfowl species. Instead, our results align with the notion that carotenoids play complex, tissue‐specific roles in oxidative balance in birds.Support or Funding InformationThe authors thank the University of Poitiers, France for providing MG with a summer internship to help support this research. The larger study was funded by the National Science Foundation (grant numbers NSF/IOS‐0746364 and ‐0925633 to KJM).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Intranasal Administration of MSC‐Derived Exosomes Modulate Status Epilepticus Induced Abnormal Plasticity of Newly Born Neurons and Microglial Activation in the Hippocampus
Authors: Atobiloye Mariam Adebola , Attaluri Sahithi , Gitai Daniel , Kodali Maheedhar , Kim Dong‐Ki , Prockop Darwin J , Shetty Ashok K 
Published: June 2021

Status epilepticus (SE) is a self‐sustaining seizure episode that causes adverse alterations in the hippocampus, which lead to a state of chronic epilepsy. We investigated the effects of mesenchymal stem cell (MSC)‐derived exosomes (small extracellular vesicles, EVs) to ameliorate the most prominent early changes induced by SE such as the abnormal plasticity of newly born neurons and activation of microglia. F344 rats were subjected to Kainic‐acid‐induced SE for 2 hours and then intranasally treated with a dose of exosomes (100 billion) or vehicle (VEH). In animals receiving VEH after SE (n=5), 20% of double cortin (DCX)‐positive newly born neurons displayed basal dendrites at 7 days post‐SE. Furthermore, the percentage of microglia with ramified morphology (resting microglia) was severely depleted in the CA1 subfield (6%) of these animals because of their activation. In contrast, in animals receiving EVs after SE (n=8), only 5% of DCX+ newly born neurons exhibited basal dendrites (p<0.0001). Also, these animals displayed a higher percentage (20%) of ramified microglia than animals receiving VEH, implying a reduced level of activation (p< 0.05). Thus, intranasal administration of MSC‐derived exosomes after SE is efficient for dampening the abnormal plasticity of newly born neurons and modulating microglial activation in the hippocampus. Basal dendrites promote abnormal connectivity between dentate granule cells and hilar/CA3 pyramidal neurons, as well as enhance granule cell to granule cell connectivity. Since both abnormal plasticity and neuroinflammation contribute to the occurrence of spontaneous seizures in the chronic phase, the results have significance.Support or Funding InformationSupported by a DOD grant to A.K.S.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sampling Bias in the Trend of Post‐Pleistocene Gracilization: How Terrain Affects Lower Limb Robusticity
Authors: Zachwieja Alexandra Jeanette , Shackelford Laura 
Published: June 2021

Many studies have documented a decrease in modern human lower limb measures of cross‐sectional geometry (CSG) throughout the Pleistocene and Holocene. These decreases are often associated with subsistence changes and technology that allowed for a more sedentary lifestyle (e.g., rise of agriculture). Italian Neolithic samples (19‐4 ka) deviate from this trend, with measures similar to earlier, highly mobile populations (Marchi, 2008; Marchi et al., 2011) despite an overall trend for reduced robusticity through Holocene Europe as a whole (Holt et al., 2018). Active populations with a lifetime of mobility on rough terrain have been shown to have higher cortical thickness and CSG properties that resist bending and torsion in the anterior‐posterior plane – which would not fit within the traditional paradigm. Here, we evaluate changes in femoral and tibial midshaft CSG measures of robusticity. These include maximum and minimum second moments of area (Imax/Imin), second moments of area in the x and y plane (Ix/Iy), polar moment of area (J), and cortical area (CA) for populations in Europe, Africa, and Asia (N = 440) throughout the past 40,000 years (Early Upper Paleolithic, Late Upper Paleolithic, Holocene) using ANOVA and linear interaction models. Generally, Early and Late Upper Paleolithic groups show no significant differences, but Early Upper Paleolithic and Holocene groups were significantly different in all femoral measures, and Late Upper Paleolithic and Holocene groups were significantly different in all measures except Ix/Iy. Linear models showed no significant effect of elevation on CSP or any interaction effects except in femoral CA (Early Upper Paleolithic, p = 0.02; Late Upper Paleolithic, p = 0.03; Holocene, p = 0.01). A paradigm of gracilization throughout time is not supported in Asian populations when they are compared within regions. Reduced robusticity in Holocene Andaman Islanders as compared to Japanese/Vietnamese samples suggest that lower limb robusticity can increase because of activities on mountainous terrain, subverting the traditional paradigm. This suggests that we cannot assume that all populations experienced a reduction in robusticity into the Holocene and we must be aware of the danger of a sampling bias in our work.Support or Funding InformationThis research was supported by Sigma Xi, NSF BCS‐0314002, and the American Museum of Natural HistoryThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Using Eye‐Tracking Data to Determine what Biochemistry Students Attend to when Completing a Three‐Dimensional Modeling Activity
Authors: Freeman Sienna , Calvert Jenifer , Terrell Cassidy , Randolph Adriane , Cortes Kimberly Linenberger 
Published: June 2021

Biochemistry students experience extraneous cognitive load when presented with distracting information while learning a new task. Consequently, the students struggle to create and store connections between old and new concepts. As this phenomenon becomes increasingly common in the classroom, there is a need to identify methods in which instructors can most effectively present new information while ensuring that students both understand the material and retain the new knowledge. In an attempt to solve this issue, the study biochemistry students were asked during a simulated classroom environment to use models of different serine proteases while answering a series of questions exploring the complementarity of the active sites and substrates. Tobii Glasses 2 were used to track student eye movements and fixations while completing the tasks. Using Tobii Pro eye tracking software, we were able to develop heat maps that assist in the identification of areas of interest on the serine protease model and accompanying worksheet during completion of the activity. With these results, we can determine if students are focusing on what the instructor intends during the activity and if not revise the activity to develop more efficient methods for instructors to present the material to their students. This will promote increased retention of the new skills presented and allow for improved processing of information, thus reducing the amount of extraneous cognitive load experienced by the student.Support or Funding InformationThis project is supported by the National Science Foundation under award number IUSE 1711402/1711425 to University of Minnesota, Rochester and Kennesaw State University.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Using Forensic Science as an Engagement Tool for Student Retention and Student Success in General Biology
Authors: Jones Candace 
Published: June 2021

Lane College is a historically black college committed to educating underserved minority students. My goal was to give students a diverse teaching and research experience and improve student success in General Biology I by engaging students through forensic sciences. Through the popularity of television shows like The First 48, CSI, NCIS, and Cold Case Files the study of forensic science has flourished and given teachers a method to teach biology, chemistry, and physics. I implemented forensic science in the laboratory in one of my two sections of General Biology I in the Spring 2018 semester. First students studied and determined the items that need to be analyzed from a mock crime scene after being introduced to some basic forensic science techniques in the first week of laboratory. Each additional week the students participated in hair analysis, fiber analysis, soil analysis, synthetic blood tests, chromatography, and DNA fingerprinting. My hope was that in this environment it would foster the students to ask questions, research background information, design experiments, gather and analyze data leading them to understand the method of scientific discovery. Additionally, the students learned to collaborate and build their critical thinking skills while becoming self‐learners. To measure the success of the intervention, I used a mixture of Forensic Science questions (n=25) that was given as a pre and post test to both sections as a way to compare the effect of the intervention. At the end of the course, the class that received the forensic science intervention had a small average increase compared with that of the class did not receive the intervention. When looking at the questions and comparing the pre and post averages 15 out of 25 had an increase 7 out of 25 had a decrease and 3 out of 25 had no change. There was a slight increase in student success in General Biology I by engaging students through forensic sciences.Support or Funding InformationNational Science Foundation Award HRD # 1623340 to MVSThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Peer‐Led Team Learning and Course‐based Undergraduate Research Experiences in General Biology and General Chemistry
Authors: Van Stry Melanie , Gaber Farag , Sklensky Diane , Ude Mba 
Published: June 2021

Lane College is a historically black college with a commitment to educating underserved minority students. Our overall goal for this project is to improve student learning of foundational concepts and retention in Biology and Chemistry through student‐centered activities within our first‐year courses. These approaches include implementation of peer‐led team learning strategies and course‐based undergraduate research experiences (CUREs) within the General Biology and General Chemistry courses. Our peer‐mentors, who serve as supplemental instructors for our General Biology and Chemistry courses are an essential element for the success of the program. They receive leadership training, through a collaboration with the Office of the First Year Experience as well as mentored undergraduate research experiences before working with our first‐year students. We have redesigned our laboratory courses to implement CUREs. Biology projects include comparative genomics in collaboration with the Genomics Education Partnership, environmental surveys of antibiotic resistant bacteria or sequence analysis of GAPC from plants growing on campus. Chemistry projects include development of novel analytical methods to measure chemical components of household products, such as using the iodine‐clock reaction to determine the amount of starch in various foods. We are assessing student learning outcomes related to understanding the scientific method using the Experimental Design Ability Test and the CURE survey developed by the GEP. In addition, we are evaluating student learning outcomes of the process of science, such as development and testing of hypotheses, recording observations within a laboratory notebook, and communication of results through oral presentations and written reports.Support or Funding InformationNSF HRD1623340This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Changing the Ligand Specificity of a Guanine Riboswitch by In Vitro Selection
Authors: Abdullah Hasan P , Morse Daniel Paul 
Published: June 2021

Riboswitches are RNA elements in messenger RNAs that regulate gene expression by undergoing a ligand‐triggered conformational change. Riboswitches bind tightly and specifically to their ligands, so they have the potential to serve as highly effective sensors in vitro. We previously modified several purine riboswitches for use in vitro and, indeed, they could detect their ligands with high sensitivity and specificity (1). To extend the utility of our sensor design, we developed an in vitro selection strategy to isolate variants of riboswitches that have altered ligand specificity. We are attempting to find variants of the guanine riboswitch that can detect hypoxanthine rather than guanine. This is a challenging task because hypoxanthine is identical to guanine except for the absence of an exocyclic amino group. We partially randomized the sequence of our guanine sensor, and used hypoxanthine as the ligand during selection. Our first experiment produced only the original, wild‐type guanine riboswitch. In hindsight, this was not surprising since the guanine riboswitch can detect hypoxanthine (albeit poorly), and it was the most abundant RNA in our initial partially‐randomized RNA pool. To solve this problem we designed a new experiment based on the C74U mutant of the guanine riboswitch. C74 forms a Watson‐Crick base pair with the bound guanine ligand. Changing C74 to U results in a riboswitch that cannot bind to guanine or hypoxanthine but can bind weakly to adenine (2). We performed a second selection in which we partially randomized the sequence of the C74U mutant, except every variant retained a U at position 74. Since the C74U mutant cannot bind to hypoxanthine, we reasoned that we could select variants that could do so by allowing hypoxanthine to form a “wobble” pair with U74. We also anticipated that we could isolate hypoxanthine sensors that discriminate against guanine due to steric clashes between the sensor and the exocyclic amino group of guanine. After 11 rounds of selection, the selected RNA pool could no longer detect adenine but could detect hypoxanthine and guanine. The sensitivity for hypoxanthine and guanine was much lower than that of the wild‐type guanine riboswitch. However, the selectivity for hypoxanthine versus guanine was slightly improved, suggesting that the pool may contain individual variants that can discriminate against guanine. We are currently determining the sequence of a few variants in the selected pool to identify RNAs that we would like to test individually for their ability to specifically detect hypoxanthine.Support or Funding InformationDefense Threat Reduction Agency [MIPR HDTRA1620511 to D.M.] Office of Naval Research Chemistry Department of the U.S. Naval AcademyThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Structural Studies on the HERV‐K Nuclear Export RNA Element
Authors: McShane Erin , Fan Lixin , Kondrup Benjamin , Wang Yun‐Xing , O'Carroll Ina 
Published: June 2021

Human endogenous retroviruses (HERVs) are remnants of ancient germline infections that comprise 8% of the human genome. A number of HERVs are actively expressed—their products assume important physiological roles in embryonic development and have been associated with cancer and autoimmune diseases. Expression of a type of HERV, HERV‐K, has been associated with amyotrophic lateral sclerosis (ALS) and some cancers. Expression of the Env protein appears to be dependent on a cis‐acting signal, RcRe, and a viral protein called Rec that mediate nuclear export of unspliced mRNAs in Crm1‐dependent manner, similar to the Rev‐RRE system in HIV. Despite low sequence similarity, the HERV‐K RcRE and HIV RRE are both characterized by a long stem and several smaller stems centered around a junction at the top of the long stem. We recently reported the three‐dimensional structure of the HIV RRE RNA and found that it is a flat, “A”‐shaped molecule (Fang et al., 2013). Based on apparent secondary structure similarities, we hypothesized that the unique “A” shape may be conserved in complex retroviruses. We examined the tertiary structure of the RcRE RNA in solution using small‐angle X‐ray scattering. Our results suggest that the two divergent retroviral elements are structurally conserved, attesting to the significance of the three‐dimensional structure in Rev‐RRE recognition. We report a structure‐ and function‐based mutational analysis of the RcRE tertirary structure.Support or Funding InformationNaval Academy Research Council (NARC)DTRA CB Technologies Service Academy Research Initiative.US Naval Academy, Chemistry DepartmentThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effect of Substrate Length on Lysine Deacetylase Activity
Authors: Nichols Kyara A , Phillips Tiffany , Toro Tasha B , Watt Terry J 
Published: June 2021

Lysine deacetylases (KDACs) are proteins involved in regulating post‐translational modification of lysine residues in proteins. Anomalous acetylation of lysine has been linked to numerous diseases, and unusual activity of lysine deacetylases often appears to be a causative factor. Our goal is to understand the substrate specificity of metal‐dependent KDACs. Here we are specifically interested in the correlation between KDAC activity with peptides derived from acetylated proteins and the activity of the same KDAC with the corresponding full‐length substrate proteins. Activity with peptides is determined by both label‐free fluorescence assays and mass spectrometry. Initial results with peptides, each derived from a single source protein but of varying length of sequence on either side of the acetylated lysine, did not reveal a correlation between peptide length and KDAC activity. The absence of such a correlation suggests important contributions from secondary structure of the substrate protein and/or contributions from amino acid residues distant from the acetylated lysine in sequence. Ongoing work with full‐length substrate proteins, obtained through recombinant expression with a site‐specific acetyllysine or using immunoprecipitation from human cell lines, provides further insight into substrate features contributing to KDAC activity. Correlation, or the lack thereof, of the activity of the KDACs with the peptide models and full‐length substrates serves as an important control on models predicting KDAC activity, which are typically based on peptides of limited variability. Understanding how substrate size and structure affect the overall activity of KDACs will also provide insight into their substrate specificity and biological targets.Support or Funding InformationThe Louisiana Cancer Research Consortium, National Institutes of Health 5G12MD007595 and TL4GM118968, National Science Foundation CHE 1625993 and MCB 1817358, and the U. S. Army Research Laboratory and the U. S. Army Research Office W911NF1810450.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Domain Specific Substrates of Lysine Deacetylase 6
Authors: Parham Imari , Eyassu Daniel G , Toro Tasha B , Watt Terry J 
Published: June 2021

Lysine deacetylases (KDACs) are enzymes that regulate the post‐translational modification of lysine by acetate. KDACs serve an important role in numerous biological processes as well as diseases such as asthma, diabetes, and certain cancers. Unlike other metal‐dependent KDACs, KDAC6 contains two catalytic domains. We hypothesize that the catalytic domains of KDAC6 catalyze deacetylation reactions independently, with each domain having several distinct substrates. Several putative substrates have been linked to KDAC6, but which catalytic domain is relevant for deacetylation is generally unclear. We have recombinantly expressed the full‐length KDAC6 as well as the individual catalytic domains. Activity of each construct was measured with peptides derived from the putative substrates, using a combination of a label‐free fluorescence assay and mass spectrometry. Activity was also determined with a selection of full‐length substrate proteins. Differences in activity of the two domains, as well as compared to the full‐length KDAC6, provide insight into the substrate specificity and relative activity of each domain. Computational methods using recently reported crystal structures of the KDAC6 domains and the tested substrates provides additional information about substrate interactions. The identification of independent domain activity and domain specific substrates using these techniques will provide the basis for a greater understanding of the biological roles of KDAC6.Support or Funding InformationThe Louisiana Cancer Research Consortium, National Institutes of Health 5G12MD007595, TL4GM118968, UL1GM118967, and R15GM129682, and National Science Foundation MCB 1817358.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.