269 research outputs found
Informal Science Engagement via Extension Exhibits: A Pilot Evaluation of Adult State Fairgoers’ Experiences, Attitudes, and Learning at Raising Nebraska
Science communication and informal science education collide in the context of Extension state fair exhibits for engaging public audiences in critical agricultural and natural resource issues impacting people’s daily lives. A need exists to employ systematic communication and education theory and techniques to effectively deliver scientific information in informal learning spaces. In an effort to apply and expand systematic instructional design thinking and research in informal science learning, this study piloted a touchscreen iPad survey evaluation (n= 93; ages 19-66) of adult state fairgoers’ demographics, experiences, attitudes, and learning during their visit to a 25,000 square-foot facility featuring an Extension museum-quality exhibit at the Nebraska State Fair in 2016. The exhibit included content such as farmers’ and ranchers’ stories, food security, soil quality, and water flow via natural landscapes and irrigation. Survey results included fairgoers’ demographics and backgrounds, as well as insights into favorite exhibit features, attitudes toward agricultural and environmental issues, and exhibit experience and attitude differences between visitors with agricultural backgrounds versus non-agricultural backgrounds. Results showed respondents were predominantly Caucasian with ties to agriculture, preferred physical and electronic engagement pieces of the exhibit compared to static text panels, and expressed slight changes in attitudes about agriculture with larger shifts in attitudes about the role of science in agriculture. Recommendations include systematically developing Extension informal learning efforts and exhibits such as the one in this study by conducting needs assessments and evaluations, as well as expanding exhibit locations, access, and topics to reach more diverse demographics
The Discursive Legitimation of Political Regimes: A Network Perspective
In this working paper, we treat legitimacy and legitimation as interactive, discursive and relational concepts: Legitimacy is socially constructed in the public spheres of (democratic) political regimes, that is, in discursive exchanges of political elites and citizens about the acceptability of these regimes. Legitimacy claims and assessments establish a link between regimes and their institutions on the one hand, and normative benchmarks on the other. Hence they may be examined with the help of discourse network analysis - a novel application of network analysis whose rationale and potential are illustrated on the basis of a corpus of legitimation statements gleaned from German and US quality newspapers. Our method enables us to discover and visualize the structures of legitimation discourses - prominent speaker types, privileged legitimation criteria and discourse coalitions - and to offer some conjectures on the link between discourses and the institutional arrangements of the German and US polities.Dieses Arbeitspapier behandelt Legitimität und Legitimation als interaktive, diskursive und relationale Konzepte: Legitimität wird in den Öffentlichkeiten (demokratischer) politischer Regimes, also in einem diskursiven Austausch von politischen Eliten und Bürgern über die Akzeptabilität politischer Herrschaft, sozial konstruiert. In Legitimitätsbehauptungen und -bewertungen wird eine Verbindung zwischen Regimes und ihren Institutionen auf der einen und normativen Kriterien auf der anderen Seite hergestellt. Diese können mit Hilfe der Diskursnetzwerkanalyse untersucht werden; Logik und Potential dieser neuen Anwendung der Netzwerkanalyse werden auf der Basis eines Korpus von Legitimationsstatements aus deutschen und US-amerikanischen Qualitätszeitungen illustriert. Unsere Methode erlaubt es, die Strukturen von Legitimationsdiskursen - etwa prominente Sprechertypen, privilegierte Legitimationskriterien und Diskurskoalitionen - aufzudecken und zu visualisieren; daraus lassen sich schließlich auch Erkenntnisse über die Verbindung zwischen Diskursen und politischen Institutionenarrangements in Deutschland und den USA ableiten
Synthesis of Indomorphan Pseudo Natural Product Inhibitors of Glucose Transporters GLUT‐1 and ‐3
Bioactive compound design based on natural product (NP) structure may be limited due to partial coverage of NP‐like chemical space and biological target space. These limitations can be overcome by combining NP‐centered strategies with fragment‐based compound design through combination of NP‐derived fragments to structurally unprecedented “pseudo natural products” (pseudo‐NPs). We describe the design, synthesis and biological evaluation of a collection of indomorphan pseudo‐NPs that combine biosynthetically unrelated indole‐ and morphan‐alkaloid fragments. Biological investigation in a cell‐based screen for modulators of glucose uptake identified the indomorphane derivative Glupin as potent inhibitor of glucose uptake. Glupin selectively targets and upregulates both, glucose transporters GLUT‐1 and GLUT‐3. Glupin suppresses glycolysis, reduces the levels of glucose‐derived metabolites and attenuates the growth of various cancer cell lines. Our findings underscore the importance of dual GLUT‐1 and GLUT‐3 inhibition to efficiently suppress tumor cell growth and the cellular rescue mechanism, which counteracts glucose scarcity
Interplay between phosphorylation and palmitoylation mediates plasma membrane targeting and sorting of GAP43.
Phosphorylation and lipidation provide posttranslational mechanisms that contribute to the distribution of cytosolic proteins in growing nerve cells. The growth-associated protein GAP43 is susceptible to both phosphorylation and S-palmitoylation and is enriched in the tips of extending neurites. However, how phosphorylation and lipidation interplay to mediate sorting of GAP43 is unclear. Using a combination of biochemical, genetic, and imaging approaches, we show that palmitoylation is required for membrane association and that phosphorylation at Ser-41 directs palmitoylated GAP43 to the plasma membrane. Plasma membrane association decreased the diffusion constant fourfold in neuritic shafts. Sorting to the neuritic tip required palmitoylation and active transport and was increased by phosphorylation-mediated plasma membrane interaction. Vesicle tracking revealed transient association of a fraction of GAP43 with exocytic vesicles and motion at a fast axonal transport rate. Simulations confirmed that a combination of diffusion, dynamic plasma membrane interaction and active transport of a small fraction of GAP43 suffices for efficient sorting to growth cones. Our data demonstrate a complex interplay between phosphorylation and lipidation in mediating the localization of GAP43 in neuronal cells. Palmitoylation tags GAP43 for global sorting by piggybacking on exocytic vesicles, whereas phosphorylation locally regulates protein mobility and plasma membrane targeting of palmitoylated GAP43
Inositol 1,4,5- Trisphosphate Receptor Function in Drosophila Insulin Producing Cells
The Inositol 1,4,5- trisphosphate receptor (InsP3R) is an intracellular ligand gated channel that releases calcium from intracellular stores in response to extracellular signals. To identify and understand physiological processes and behavior that depends on the InsP3 signaling pathway at a systemic level, we are studying Drosophila mutants for the InsP3R (itpr) gene. Here, we show that growth defects precede larval lethality and both are a consequence of the inability to feed normally. Moreover, restoring InsP3R function in insulin producing cells (IPCs) in the larval brain rescues the feeding deficit, growth and lethality in the itpr mutants to a significant extent. We have previously demonstrated a critical requirement for InsP3R activity in neuronal cells, specifically in aminergic interneurons, for larval viability. Processes from the IPCs and aminergic domain are closely apposed in the third instar larval brain with no visible cellular overlap. Ubiquitous depletion of itpr by dsRNA results in feeding deficits leading to larval lethality similar to the itpr mutant phenotype. However, when itpr is depleted specifically in IPCs or aminergic neurons, the larvae are viable. These data support a model where InsP3R activity in non-overlapping neuronal domains independently rescues larval itpr phenotypes by non-cell autonomous mechanisms
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The highly potent AhR agonist picoberin modulates Hh-dependent osteoblast differentiation
Identification and analysis of small molecule bioactivity in target-agnostic cellular assays and monitoring changes in phenotype followed by identification of the biological target are a powerful approach for the identification of novel bioactive chemical matter in particular when the monitored phenotype is disease-related and physiologically relevant. Profiling methods that enable the unbiased analysis of compound-perturbed states can suggest mechanisms of action or even targets for bioactive small molecules and may yield novel insights into biology. Here we report the enantioselective synthesis of natural-product-inspired 8-oxotetrahydroprotoberberines and the identification of Picoberin, a low picomolar inhibitor of Hedgehog (Hh)-induced osteoblast differentiation. Global transcriptome and proteome profiling revealed the aryl hydrocarbon receptor (AhR) as the molecular target of this compound and identified a cross talk between Hh and AhR signaling during osteoblast differentiation
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The pseudo‐natural product rhonin targets RHOGDI
For the discovery of novel chemical matter generally endowed with bioactivity, strategies may be particularly efficient that combine previous insight about biological relevance, e.g., natural product (NP) structure, with methods that enable efficient coverage of chemical space, such as fragment-based design. We describe the de novo combination of different 5-membered NP-derived N-heteroatom fragments to structurally unprecedented “pseudo-natural products” in an efficient complexity-generating and enantioselective one-pot synthesis sequence. The pseudo-NPs inherit characteristic elements of NP structure but occupy areas of chemical space not covered by NP-derived chemotypes, and may have novel biological targets. Investigation of the pseudo-NPs in unbiased phenotypic assays and target identification led to the discovery of the first small-molecule ligand of the RHO GDP-dissociation inhibitor 1 (RHOGDI1), termed Rhonin. Rhonin inhibits the binding of the RHOGDI1 chaperone to GDP-bound RHO GTPases and alters the subcellular localization of RHO GTPases
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The pseudo‐natural product rhonin targets RHOGDI
For the discovery of novel chemical matter generally endowed with bioactivity, strategies may be particularly efficient that combine previous insight about biological relevance, e.g., natural product (NP) structure, with methods that enable efficient coverage of chemical space, such as fragment-based design. We describe the de novo combination of different 5-membered NP-derived N-heteroatom fragments to structurally unprecedented “pseudo-natural products” in an efficient complexity-generating and enantioselective one-pot synthesis sequence. The pseudo-NPs inherit characteristic elements of NP structure but occupy areas of chemical space not covered by NP-derived chemotypes, and may have novel biological targets. Investigation of the pseudo-NPs in unbiased phenotypic assays and target identification led to the discovery of the first small-molecule ligand of the RHO GDP-dissociation inhibitor 1 (RHOGDI1), termed Rhonin. Rhonin inhibits the binding of the RHOGDI1 chaperone to GDP-bound RHO GTPases and alters the subcellular localization of RHO GTPases
Semantics in Support of Biodiversity Knowledge Discovery: An Introduction to the Biological Collections Ontology and Related Ontologies
The study of biodiversity spans many disciplines and includes data pertaining to species distributions and abundances, genetic sequences, trait measurements, and ecological niches, complemented by information on collection and measurement protocols. A review of the current landscape of metadata standards and ontologies in biodiversity science suggests that existing standards such as the Darwin Core terminology are inadequate for describing biodiversity data in a semantically meaningful and computationally useful way. Existing ontologies, such as the Gene Ontology and others in the Open Biological and Biomedical Ontologies (OBO) Foundry library, provide a semantic structure but lack many of the necessary terms to describe biodiversity data in all its dimensions. In this paper, we describe the motivation for and ongoing development of a new Biological Collections Ontology, the Environment Ontology, and the Population and Community Ontology. These ontologies share the aim of improving data aggregation and integration across the biodiversity domain and can be used to describe physical samples and sampling processes (for example, collection, extraction, and preservation techniques), as well as biodiversity observations that involve no physical sampling. Together they encompass studies of: 1) individual organisms, including voucher specimens from ecological studies and museum specimens, 2) bulk or environmental samples (e.g., gut contents, soil, water) that include DNA, other molecules, and potentially many organisms, especially microbes, and 3) survey-based ecological observations. We discuss how these ontologies can be applied to biodiversity use cases that span genetic, organismal, and ecosystem levels of organization. We argue that if adopted as a standard and rigorously applied and enriched by the biodiversity community, these ontologies would significantly reduce barriers to data discovery, integration, and exchange among biodiversity resources and researchers
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