1,720,958 research outputs found
Optimizing Chitosan-Functionalized Hollow Silica Microspheres for Isolation and Concentration of Nucleic Acids
No full textThis research investigates Wastewater-Based Epidemiology (WBE), a tool utilized for detection and concentration analysis of wastewater samples. WBE is useful for monitoring and management of public health threats like viral outbreaks such as COVID-19. In current research, the development of this assay uses the unique properties of hollow silica microspheres coupled with chitosan as a binding agent, a method effective in the detection of various nucleic acids (DNA/RNA) and other antigens in wastewater samples. The utilization of hollow silica microspheres, selected for the high surface area and buoyant properties, aided by chitosan, creates an efficient and selective binding process of nonspecific negatively charged binding. This combination can be optimized for the sensitivity of detection but also supports the capture of a wide range of viral particles and RNA molecules. Capture of oligonucleotides is achieved by chitosan binding to the surface of the hollow silica microspheres.
This thesis research served to find the optimal conditions for nucleic acid binding, isolation, and long-term microsphere stability when functionalized with chitosan. The preparation time of functionalized microspheres has been reduced. The incubation time of functionalized microspheres with L-Cysteine has been reduced to 10 minutes under end-over-end rotation. The optimal binding conditions of oligonucleotides has been found utilizing a surrogate. It was found that the functionalized microspheres can bind nucleic acids at saturation within 1 hour. The incorporation of reduced incubation times has reduced the overall protocol by over 24hrs. A protocol has been developed to stabilize microspheres after lyophilization and storage. The addition of trehalose, a cryoprotectant, increases stability after lyophilization and storage. SEM or scanning electron microscope was used to image the chitosan shell on the hollow silica microspheres. The functionalized microspheres containing various treatments applied was examined for disruptions in the chitosan surface and binding kinetics.Biolog
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
Mechanisms of Exosome-Autophagy Interplay in Host Response to the Cytoplasmic RNA Virus (Rift Valley Fever Virus) and Development of Promising Countermeasure Approaches
Get PDFRift Valley fever virus (RVFV) is from the Bunyaviridae family, genus Phlebovirus, and causes Rift Valley Fever (RVF) disease for which no licensed vaccines or effective therapies are available. RVF is an important emerging zoonotic disease that poses serious threat to livestock and human life, and its causative agent, RVFV, is classified as a pathogen of highest concern (Category A) by NIAID. While RVFV is primarily transmitted by mosquitoes, human cases can also be acquired through contact with blood or organs of an infected animal. RVF disease causes abortion storms in ruminants that can reach 100%, and in serious human cases it can lead to encephalitis, hemorrhagic fever, hepatic disease, ocular disease, and mortality. Case fatality rates from RVFV infection can reach as high as 30% in non-endemic regions. RVFV is an enveloped negative sense single-stranded RNA virus with a diameter between 80-120 nm, and the RVFV genome consists of three segments that are named based on their relative sizes: Large (L), Medium (M), and Small (S). Autophagy is an intracellular pathway that allows for the degradation of cytoplasmic organelles during cellular stress, and is also an important host response mechanism during several pathogenic infections. The role of autophagy during viral infections is complex. In some cases, it slows the progression of the infection, whereas, in some other cases the virus uses the autophagy system to enhance its replication. In a previous publication, we have demonstrated that exosomes released from cells infected with RVFV (designated as EXi-RVFV) protect the cells that receive them against RVFV infection through activation of autophagy. The results showed that EXi-RVFV activate the viral RNA sensor RIG-I to cause IFN-B activation and that IFN-B in turn activates autophagy. Thus, treatment of naïve U937 monocytes with EXi-RVFV leads to a significant (2 fold) induction of autophagy as compared to untreated cells or cells treated with equivalent amounts of exosomes purified from uninfected cells (EXu). We have also deciphered the molecular mechanisms through which IFN-B activation leads to activation of autophagy in the recipient cells. Our result show that the signaling proteins AKT, mTOR, and ERK1/2 are involved in the observed autophagy activation, as well as the core autophagy proteins Beclin1 and ATG5. Furthermore, we have analyzed the type of autophagy involved, to determine whether the LC3-Associated Phagocytosis (LAP) or the canonical autophagy pathway becomes engaged. Based on both protein marker analysis and electron microscopy studies, we have demonstrated that the canonical pathway and not LAP autophagy is induced by EXi-RVFV treatment of naïve U937 cells. These results provide insights into the host response mechanisms that can be utilized towards development of novel countermeasures against RVFV in the future.This work is embargoed by the author and will not be publicly available until 2024-08-31.2024-08-3
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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