1,720,960 research outputs found

    Assessing the practice of LuPOR for poor responders: a prospective study evaluating follicular fluid cfDNA levels during natural IVF cycles

    No full text
    Purpose: The aim of this study is to provide data on the practice of Luteal Phase Oocyte Retrieval (LuPOR). The authors assess cell-free DNA levels in follicular fluid (ff cfDNA) from poor responders undergoing natural cycles, and comparing it to respective data originating from follicular phase oocyte retrievals. Methods: Forty-seven women were eligible for this prospective study. Participants were classified as poor responders based on Bologna criteria while being detected with a second follicular wave. Follicular fluid was collected and prepared for cfDNA extraction. Levels of cfDNA were quantified via Q-PCR employing the ALU115 and ALU247 primers. These primers are associated with apoptotic and necrotic events. Levels of ff cfDNA resulting from follicular phase oocyte retrieval (FoPOR) and LuPOR-performed in a single menstrual cycle were associated with the number and maturation status of yielded oocytes and the number and fertilization status of resulting zygotes. Survival rate following thawing of cryopreserved zygotes, along with the resulting number of cleavage stage and blastocyst stage embryos are provided. Results: Mean levels of ALU115 were significantly lower during FoPOR when compared to LuPOR (0.79 ± 0.72 vs 1.46 ± 1.59 ng/μl, p = 0.02). Regarding the FoPOR group, a significant positive correlation of serum estradiol and ALU115 concentration (p = 0.04) was revealed. A significant negative correlation between serum estradiol and cfDNA integrity was observed both during FoPOR (p = 0.03) and LuPOR (p = 0.03). A significant lower number of retrieved (1.09 ± 0.28 vs 1.29 ± 0.58, p = 0.02) and MII oocytes (0.77 ± 0.55 vs 1.08 ± 0.61, p = 0.02) was observed when comparing the FoPOR to LuPOR groups respectively. The integrity of cfDNA was observed to be higher in FoPOR originating embryos that arrested either prior to cleavage (0.28 ± 0.13 vs 0.17 ± 0.10, p = 0.006) or prior to blastocyst formation (0.28 ± 0.12 vs 0.13 ± 0.06, p = 0.04). In the case of LuPOR originating embryos, cfDNA integrity was observed to be higher in embryos that arrested only prior to the blastocyst stage (0.27 ± 0.20 vs 0.11 ± 0.07, p = 0.008). Similarly, cfDNA integrity was observed to be lower in top quality blastocysts originating from FoPOR (0.07 ± 0.04 vs 0.17 ± 0.05, p = 0.03) and in top quality cleavage stage embryos (0.09 ± 0.06 vs 0.31 ± 0.22, p = 0.01) and blastocysts (0.06 ± 0.02 vs 0.14 ± 0.06, p = 0.02) originating from LuPOR. Conclusions: Our results indicate that ff originating from LuPOR presents with higher levels of cfDNA. The higher cfDNA levels are attributed to mainly apoptotic events, as the ALU247 levels and DNA integrity did not differ statistically significantly between FoPOR and LuPOR. The absolute mean level of ALU247 corresponding to necrotic events was higher in LuPOR. Regarding embryological data, cfDNA integrity was correlated with both number and quality of cleavage stage embryos in both FoPOR and LuPOR, along with blastocyst stage embryos in LuPOR. Necrotic events were associated with poorer blastocyst formation rate and blastocyst quality in LuPOR. As the comparison between FoPOR and LuPOR results to similar IVF laboratory data, the practice of LuPOR may stand as a promising approach for poor responders, while it merits further investigation. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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 link
    We 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 link
    We 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

    Author Index

    No full text
    Nao informado

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We 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
    corecore