1,721,023 research outputs found
Experimental data about mammalian sperm function and survival. Effects of Roundup and its main component, glyphosate
No full textThe wide use of glyphosate-based herbicides (GBHs) has become a matter of concern due to its potential harmful effects on human health, including men fertility. The study investigated, using the pig as a model, the impact of pure glyphosate and its most known commercial formulation, Roundup, on sperm function and survival.
These data sets contain the raw data of the flow cytometry analysis of sperm parameters (sperm viability, acrosome integrity, mitochondrial activity and DNA fragmentation) and motility analysis by computer-assisted sperm analysis (CASA) of fresh commercial semen doses incubated with different concentrations (0–360 μg/mL) of glyphosate (GLY) or Roundup (R), at the equivalent GLY concentration for 3 h
Combining reduced glutathione and ascorbic acid has supplementary beneficial effects on boar sperm cryotolerance
No full textThe main aim of this work was to evaluate how supplementing freezing and thawing media with reduced glutathione (GSH) and l-ascorbic acid (AA) affected the quality parameters of frozen-thawed boar spermatozoa. With this purpose, semen samples of 12 ejaculates coming from 12 boars were used. Each ejaculate was split into seven aliquots to which 5 mM of GSH and 100 μM of AA were added separately or together at two different steps of freeze-thawing. Various sperm parameters (levels of free cysteine residues in sperm nucleoproteins, sperm viability, acrosome membrane integrity, intracellular peroxide and superoxide levels [ROS], and total and progressive motility) were evaluated before freezing and at 30 and 240 minutes after thawing. Both GSH and AA significantly improved boar sperm cryotolerance when they were separately added to freezing and thawing media. However, the highest improvement was recorded when both freezing and thawing media were supplemented with 5 mM of GSH plus 100 μM of AA. This improvement was observed in sperm viability and acrosome integrity, sperm motility, and nucleoprotein structure. Although ROS levels were not much increased by freeze-thawing procedures, the addition of GSH and AA to both freezing and thawing extenders significantly decreased intracellular peroxide levels and had no impact on superoxide levels. According to our results, we can conclude that supplementation of freezing and thawing media with both GSH and AA has a combined, beneficial effect on frozen-thawed boar sperm, which is greater than that obtained with the separate addition of either GSH or AA
Involvement of extracellular vesicle-encapsulated miRNAs in human reproductive disorders: a systematic review
Full text linkIn recent years, extracellular vesicles (EVs) have emerged as essential players in cell-to-cell communication, particularly having an active regulating role in biological systems. Because reproductive-associated processes are not exempt of this communication, multiple studies have been devoted to this realm, focusing on gamete maturation, embryo implantation or fetal development. The aim of the present review was to comprehensively and systematically collect evidence about the function of the microRNA (miRNA) encapsulated in EVs isolated from different reproductive tissues or fluids in reproductive-related diseases. Following PRISMA guidelines, we conducted a systematic search of the literature published in MEDLINE-PubMed until the end of February 2021. After selection, 32 studies were included in the qualitative review comparing the miRNA expression profile in EVs between different pathological disorders. Most reports showed the potential of the miRNAs carried by EVs to be used as putative biomarkers of reproductive disorders, including pregnancy affections, disease progression and quality of preimplantation embryos. The most relevant miRNAs were found to be highly heterogeneous among studies, with some conflicting results. Further research is thus warranted to address whether cofounding factors, such as the methods to isolate EVs and miRNAs, the subset of EVs, the criteria of patient selection, the timing of sample retrieval, or any other factor, may explain the inconsistencies between studies
Implementing an open-access CASA software for the assessment of stallion sperm motility: Relationship with other sperm quality parameters
Full text linkSetting an open-access computer assisted sperm analysis (CASA) may benefit the evaluation of motility in mammalian sperm, especially when economic constraints do not allow the use of a commercial system. There have been successful attempts to develop such a device in Zebra fish sperm and the system has been used in very few studies on mammalian spermatozoa. Against this background, the present study aimed at developing an open-access CASA system for mammalian sperm using the horse as a model and based upon the Image J software previously established for Zebra fish sperm. Along with determining the sperm progressive motility and other kinetic parameters (such as amplitude of lateral head displacement), the “results” window was adjusted to simplify subsequent statistical analyses. The path window was enriched with colored sperm trajectories on the basis of the subpopulation they belong to and a number that allowed the sperm track to be associated to the sperm motility data shown in the “results” window. Data obtained from the novel plugin (named as CASA_bgm) were compared with those of the commercial CASA Hamilton-Thorn IVOS Vers.12, through Bland Altman's plots. While the percentage of total and progressive motile sperm, VCL, VAP, VSL, LIN and STR and ALH were in agreement with those obtained with the commercial system, BCF significantly differed between the two systems probably due to their settings. Interestingly, a positive and significant correlation between the percentages of total motile sperm evaluated through CASA_bgm and those showing high mitochondrial membrane potential evaluated by JC-1 staining was found. In conclusion, CASA_bgm ImageJ plugin could be useful and reliable for stallion sperm motility analysis and it is our aim to apply this system to other mammalian species
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
Ovarian follicular flushing as a means of increasing oocyte yield and in vitro embryo production in cattle
Full text linkContext The number of developmentally competent cumulus-oocyte complexes (COCs) retrieved during Ovum Pick-Up (OPU) determines success in both bovine and human assisted reproduction. Follicular flushing for COC retrieval is practicsed widely in humans but not in cattle. Aims To determine the benefits of follicular flushing in cattle and assess the merits of a novel 16G double-lumen needle ('OxIVF') that flushes laterally to the needle shaft. Methods Experiment 1 flushed 655 antral follicles (≥7mm) from 255 abattoir-derived cattle ovaries. In Experiment 2, 12 Holstein heifers underwent two cycles of OPU in a cross-over design comparing both needle types. In Experiment 3, 11 Holstein heifers underwent two cycles of OPU using the OxIVF needle in a cross-over design: flushing (≥7mm follicles) vs a 'Hybrid' approach of flushing (≥7mm follicles) and aspiration (5-7mm follicles); followed by two cycles of standard follicle aspiration (>5mm follicles). Key results In Experiment 1, COC recovery was greater (P =0.034) for the OxIVF vs Standard needle (mean±s.e.; 74.1±2.10% vs 67.0±2.23%); yield of Grade 1 COCs was also greater (20.1±1.97% vs 8.2±1.38%; P P =0.045) for the OxIVF vs Standard needle (89.1±2.98% vs 79.6±3.47%). Day 6 embryo yield was also greater (P =0.017) for the OxIVF vs Standard needle (87.2±4.38% vs 67.6±6.73%). In Experiment 3, recovery of COCs was greater (P =0.033) for 'Flush' vs 'Aspirate' groups (82.1±5.06% vs 66.2±3.48%). However, number of Day 8 blastocysts for the 'Hybrid' vs 'Flush' approach (9.2±1.39vs 6.5±1.05 per cycle) did not reach statistical significance. Conclusions Follicular flushing using the OxIVF needle, embracing the 'Hybrid' approach, has the potential to increase oocyte retrieval and blastocyst number per donor cycle in cattle but requires further validation. Implications Larger scale studies will seek to confirm benefits of follicular flushing using the OxIVF needle in cattle. Future studies should consider applications in both equine and human assisted reproduction
- …
