1,720,955 research outputs found
Chloride binding does not influence prestin motor speed at very high frequencies in the mouse outer hair cell
No full textBehavioral and electrophysiological assessment of hearing function in mice with deficient sound encoding at inner hair cell ribbon synapse
Get PDFAuditory synaptopathy in humans is characterized by poor speech perception especially in noisy environments despite of preserved active cochlear amplification. The ABR of affected patients is absent or shows a significant reduction of wave I amplitude caused by abnormal function of inner hair cell ribbon synapses. Here, I characterized auditory function in mouse models of auditory synaptopathy by comparing electrophysiological (ABR, ASSR, and DPOAE) and behavioral experiments (acoustic startle reflexes, operant conditioning in the shuttle box and Intellicage). The best behavioral results were obtained in the Intellicage, which produced consistent repeatable results in thresholds, gap detection, and frequency discrimination experiments. The subsequent testing of the same mice in the threshold and threshold in noise experiment was possible and demonstrated the expected masking effect in WT animals. In contrast, in Ribeye mutants, the introduction of background noise resulted in a decrease in discrimination ability.
Ribeye KO mice: Analysis of ABR traces recorded from Ribeye KO revealed a significant reduction in wave I and III amplitudes, suggesting impaired activation of the auditory nerve and superior olivary complex. The behavioral threshold estimation in quiet for the Ribeye KO mice was comparable to the mild threshold shift seen in their ABRs. Introduction of noise had the expected masking effect in WT and heterozygous mice, while Ribeye KO mice showed a severe deterioration in discrimination performance when noise was introduced.
Auditory phenotype of OtofQX mice and Otof2M mutant mice: OtofQX -/- mice showed absence of ABR waves with preservation of the summating potential. The hearing deficits in OtofQX -/- mice resembled the auditory phenotype described in human patients with the same mutation, making this mouse model a good candidate for gene therapy trials. Otof2M mutants exhibited a moderate hearing deficit with a significant amplitude reduction in ABR waves I and III. Otof2M mutants showed an impaired gap detection ability in comparison to their WT littermates. Such pathology could explain the deficient speech perception in patients with OTOF mutations.
Otof -/- rescue: Viral gene therapy partially restored hearing function in Otof -/- mice with clearly distinguishable ABR waves II, IV and V and partial restoration of wave I and III, achieving click thresholds of ~ 60 dB SPL in 66% of Otof -/- mice injected with AAV-PHP.B or AAV-PHP.eB carrying DNA coding full-length otoferlin. Rescued Otof -/- mice were capable of detecting sound stimuli in the Intellicage. Results suggested that viral gene therapy of DFNB9 using a single overloaded AAV vector is feasible and might reduce the complexity of gene transfer when compared to dual-AAV approaches.
CAPS exon 2 deletion mice: Deletion of CAPS1 exon2 was detected in a complex human phenotype in patients suffering from bipolar disorder. In mice, this mutation caused no obvious hearing impairment as evidenced by DPOAE and ABR findings; preserved ABR thresholds and comparable amplitude to their WT littermates. Interestingly, there was a reduction in ASSR amplitudes at lower modulation frequencies (110-400). Those findings suggest a role for CAPS1 protein in auditory brainstem neurons.
ABR results for mutants with an auditory synaptopathy phenotype showed a reduction in the amplitude of ABR waves I and III in several mutant mouse lines (Ribeye, Otof2M, Otit CBA and Otof rescue). The reduction was less obvious for waves II and IV which might be explained by central compensatory mechanisms augmenting their response.2023-03-1
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
