1,720,955 research outputs found
Molecular Visualization Laboratory (BIOL4450): Molecular Visualization of Phosphoethanolamine Methyltransferase from Plasmodium falciparum
No full textMalaria is a major worldwide health threat as this disease, caused by different species of Plasmodium parasites, results in over 1 million deaths and 300 million clinical cases each year. Due to the large negative impacts which Malaria has on humanity, it is important to research and identify novel biochemical pathways that avoid drug resistance. One such pathway that has potential to highlight specific drug targets is the phosphobase methylation pathway which synthesizes phosphocholine, a precursor of phosphatidylcholine. A key enzyme of this pathway, specific to Plasmodium falciparum, is the phosphoethanolamine methyltransferase (PfPMT) enzyme which is responsible for sequential methylation reactions. PfPMT holds a unique 3D structure when compared to its other forms found in plants and protists making it a novel target for drug development. Specifically, the conformation of PfPMT in complexed with phosphoethanolamine (pEA) and S-adenosylhomocysteine (SAH) provides insights into the structure and function of its active site. In the Molecular Visualization Laboratory (BIOL4450) class at KSU, to gain a better understanding of the PfPMT 3D structure, biochemical methods such as site-directed mutagenesis and protein purification were used to perform X-ray crystallography. Additionally, X-ray crystallography experiments were conducted as a vital source to collect information on the 3D structures of PMT and interactions with ligands. Finally, the 3D structure of PfPMT was visualized and analyzed using a series of tools, including virtual reality (VR), augmented reality (AR), and 3D printing, to contribute to the field of STEAM (science, technology, engineering, art, and math) and improve academic understanding of protein biochemistry. Through use of biochemical techniques and direct analysis of 3D visualization methods of PMT will contribute to a greater understanding of its active site function and structure. With new insights on PMT 3D structure and function, novel drug approaches may be developed in the future
Understanding the Role of hlh-14 and ceh-27 in the M4 Motor Neuron in C. elegans
No full textAttention Deficit Hyperactivity Disorder (ADHD) affects millions worldwide and can shape social interactions, health factors, and overall quality of life. The genetic mechanisms underlying ADHD, however, are not well defined. One gene linked to ADHD, Nkx2.1, plays a key role in neuronal differentiation across mammals. Because these transcriptional networks are deeply conserved, studying Nkx2.1’s ortholog, ceh-27, in C. elegans allows these mechanisms to be examined in a simpler, well-mapped nervous system. The worm’s invariant cell lineage and genetic accessibility make it an ideal model for discovering conserved neurodevelopmental pathways. This study investigates the regulatory relationship between ceh-27 and hlh-14, a basic helix-loop-helix transcription factor that promotes early neurogenesis, in the M4 motor neuron. Using C. elegans strains expressing hlh-14::GFP, fluorescence microscopy will compare hlh-14 expression in wild-type and ceh-27 mutant embryos. Spatial and intensity analyses will determine whether ceh-27 represses or activates hlh-14 during M4 specification. By defining how ceh-27 interacts with hlh-14 in a single, invariant neuron (M4), this research will provide more insight into the transcriptional hierarchies that govern neuronal identity in C. elegans and conserved mechanisms relevant to neurodevelopmental disorders
Characterization of ceh-27/Nkx2.1 in Caenorhabditis elegans Pharyngeal Nervous System Development
No full textAttention Deficit Hyperactivity Disorder (ADHD) is a polygenic hereditary disorder affecting roughly 250 million people worldwide. The ADHD associated gene Nkx2.1 codes for the homeobox transcription factor NKX2-1, which plays a critical role in regulating gene expression by binding to specific DNA sequences and controlling the transcription of target genes. Heterozygous mutations in Nkx2.1 are linked to the development of benign hereditary chorea, which also presents as ADHD in adults. Understanding the gene regulatory environment around Nkx2.1 is critical for characterizing its downstream effects on neurodevelopment and can help identify other genes that contribute to ADHD. Nkx2.1 is highly conserved across phyla, allowing the use of model organisms to better understand Nkx2.1 function. The nematode Caenorhabditis elegans (C. elegans) can be used to study Nkx2.1 through its orthologous homeobox gene ceh-27. C. elegans has an invariant cell lineage, well defined nervous system, and fully mapped genome which makes it ideal for characterizing the role of ceh-27. Our preliminary data suggests that ceh-27 plays a role in neuronal specification and is required for normal pharyngeal development. However, its specific regulatory targets remain unclear. To further investigate ceh-27’s gene regulatory environment and its downstream influence on pharynx development, genetically encoded florescent reporters were crossed into a ceh-27 null mutant allele to highlight different cell types within and around the pharynx. Through the use of confocal time-lapse video microscopy and direct analysis of pharyngeal specific markers, we aim to confirm that ceh-27 has key roles in embryonic pharyngeal nervous system development. Future directions include using single cell RNA sequencing to further characterize ceh-27 transcriptional targets
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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