1,723,010 research outputs found
Investigating Dopamine Initiated Hypoactivity in Hyperactive Fumin Mutant Drosophila Melanogaster
No full textStudying the mechanisms of dopamine (DA) metabolism is critical to our understanding of neurological disorders such as depression, attention-deficit/hyperactivity disorder (ADHD), Schizophrenia, and Parkinson’s Disease and to the development of pharmacological treatments. The fruit fly serves as a useful model to study neurotransmitters such as dopamine and serotonin (5-HT) because they are highly conserved at the molecular and behavioral levels across the animal kingdom. A mutation in the drosophila dopamine transporter (dDAT), named fumin, exhibits hyperactivity due to increased postsynaptic DA signaling. Interestingly, administration of L-dopa, a precursor to DA, or amphetamine (AMPH), an illicit psychostimulant that increases DA, to fumin mutants results in a significant decrease in locomotor activity.
We hypothesize that this hypoactivity is due to either signaling at the DA autoreceptor, dD2R, or the false production and transmission of DA via 5-HT neurons, which utilize dopa decarboxylase (DDC), an enzyme that catalyzes the final step in DA and 5-HT production. To test these hypotheses, we employed drosophila activity monitors (DAMs) to track fly locomotor activity in different genetic and pharmacological backgrounds and analyzed this data using R. First, we established a dose-response curve of wild-type and fumin flies on control food and L-dopa food to determine the optimal dose to observe the hypoactive phenotype. Second, we knocked down dD2R specifically in DA neurons in fumin flies and administered L-dopa to determine whether hypoactivity persists. Lastly, we knocked down the DDC enzyme in 5-HT neurons to determine whether the enzymatic conversion of L-dopa to DA in 5-HT neurons leads to unexpected hypoactivity.
Preliminary data shows a significant decrease in daytime locomotor activity in the fumin flies with an inhibited DA D2-autoreceptor, suggesting the potential up-regulation of another DA uptake mechanism, which requires further investigation. This research has the potential to inform us of mechanisms for side effects related to L-dopa-based medications, the treatment of ADHD via DA and AMPH-based medications, and may provide a basis for future studies regarding the potential of 5-HT neurons to release DA at the synapse
Glandular trichome-derived sesquiterpenes of wild tomato accessions (Solanum habrochaites) affect aphid performance and feeding behavior
No full textWang, Fumin, Park, Yong-Lak, Gutensohn, Michael (2020): Glandular trichome-derived sesquiterpenes of wild tomato accessions (Solanum habrochaites) affect aphid performance and feeding behavior. Phytochemistry (112532) 180: 1-11, DOI: 10.1016/j.phytochem.2020.112532, URL: http://dx.doi.org/10.1016/j.phytochem.2020.11253
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Face recognition using linear representation ensembles
No full textAbstract not availableHanxi Li, Fumin Shen, Chunhua Shen, Yang Yang, Yongsheng Ga
Enological evaluation of the attitude of the grapevine Fumin to give varietal wines
No full textThe aim of this work was to evaluate and compare the impact of three different types of winemaking of Fumin grapes in which the individual or combined effects of pre-fermentative and post-fermentative maceration, barrique and steel aging, malolactic fermentation and microoxygenation were tested. The sensory profiling of the wines obtained as well as the changes occurring in the chemical composition, colour parameters, polyphenol and aroma compounds, volatile phenols and biogenic amines were determined according to O.I.V. methods and metabolomic approaches thorough UPLC-MS
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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