1,721,218 research outputs found
Olfactory perception of Hermetia illucens: a source of inspiration for the development of new biosensors for the monitoring of agrifood products shelf life
No full text: Insect physiology study at the molecular level and innovative technology implementation allows the
development of applications useful to human. An example is the olfactory perception of Hermetia illucens, a
saprophagous Diptera that has aroused interest for organic waste bioconversion. Females oviposit on decaying
organic matter and larvae feed on it. Through RNAseq, de novo assembly and annotation of larval, male/female adult
transcriptomes, we identified H. illucens Odorant Binding Proteins (OBPs) that mediate chemoreception of volatile
organic compounds (VOCs) found in decaying substrates. We detected 15 HillOBPs expressed both in larvae and
adults. The use of OBPs specific for organic decomposition VOCs are proposed as sensing layers of innovative QuartzCrystal- Microbalances (QCMs) sensors, for monitoring food product preservation and shelf-life, in a new approach to
food logistics. Affinities with 57 identified VOCs, emitted by different decomposing substrates colonized by H.illucens
larvae, were calculated by molecular docking technique and were confirmed for 4 cloned, expressed and purified
HillOBPs immobilized on a gold-layer of QCMs. These experiments provided useful information about biosensor
selectivity, as the ability to discriminate ligands of different nature. Four compounds indicative of lipidic decomposition
were detected with high affinity in a pool of VOCs, known to be spoilage markers
Structure and biotechnological applications of odorant-binding proteins
No full textOdorant-binding proteins (OBPs) are small soluble polypeptides found in sensory organs of vertebrates and insects as well as in secretory glands and are dedicated to detection and release of chemical stimuli. OBPs of vertebrates belong to the family of lipocalin proteins, while those of insects are folded into α-helical domains. Both types of architectures are extremely stable to temperature, organic solvents and proteolytic digestion. These characteristics make OBPs suitable elements for fabricating biosensors to be used in the environment, as well as for other biotechnological applications. The affinity of OBPs for small volatile organic compounds is in the micromolar range, and they have broad specificity to a range of ligands. For biotechnological applications, OBPs can be expressed in bacterial systems at low cost and are easily purified. The large amount of information available on their structures and affinities to different molecules should allow the design of specific mutants with desired characteristics and represent a solid base for tailoring OBPs for different applications
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
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
Development of amperometric gas sensors for detection of N2O in low concentrations
No full textTwo types of amperometric sensors for nitrous oxide gas have been investigated: unshielded electrodes and solid polymer bonded electrodes. Gold, silver and platinum were employed as working electrodes in the unshielded system. Both aqueous and non-aqueous solutions were used as electrolyte. The solid polymer bonded electrode has indicated to be a promising candidate for nitrous oxide gas sensors with increased sensitivity due to direct contact of the gas with the electrode
Development of amperometric gas sensors for detection of N2O in low concentrations
No full textTwo types of amperometric sensors for nitrous oxide gas have been investigated: unshielded electrodes and solid polymer bonded electrodes. Gold, silver and platinum were employed as working electrodes in the unshielded system. Both aqueous and non-aqueous solutions were used as electrolyte. The solid polymer bonded electrode has indicated to be a promising candidate for nitrous oxide gas sensors with increased sensitivity due to direct contact of the gas with the electrode
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