Search results for "Insemination"
showing 10 items of 55 documents
Postcopulatory sexual selection generates speciation phenotypes in Drosophila.
2013
Background: Identifying traits that reproductively isolate species and the selective forces underlying their divergence is a central goal of evolutionary biology and speciation research. There is growing recognition that postcopulatory sexual selection which can drive rapid diversification of interacting ejaculate and female reproductive tract traits that mediate sperm competition may be an engine of speciation. Conspecific sperm precedence (CSP) is a taxonomically widespread form of reproductive isolation but the selective causes and divergent traits responsible for CSP are poorly understood. Results: To test the hypothesis that postcopulatory sexual selection can generate reproductive iso…
The evolution of sperm morphometry in pheasants
2007
7 pages; International audience; Post-copulatory sexual selection is thought to be a potent evolutionary force driving the diversification of sperm shape and function across species. In birds, insemination and fertilization are separated in time and sperm storage increases the duration of sperm-female interaction and hence the opportunity for sperm competition and cryptic female choice. We performed a comparative study of 24 pheasant species (Phasianidae, Galliformes) to establish the relative importance of sperm competition and the duration of sperm storage for the evolution of sperm morphometry (i.e. size of different sperm traits). We found that sperm size traits were negatively associat…
Embryo multinucleation at the two-cell stage is an independent predictor of intracytoplasmic sperm injection outcomes.
2016
Objective To determine the prognostic impact of the nuclear status at the two-cell stage on intracytoplasmic sperm injection (ICSI) outcomes. Design Retrospective study. Setting Hospital. Patient(s) Only ICSI cycles with time-lapse monitoring of transferred embryos with known implantation/delivery data from November 2012 to December 2014 were included. A total of 2,449 embryos were assessed for multinucleation rates at the two- and four-cell stage, and 608 transferred embryos were studied for ICSI outcomes. Intervention(s) None. Main Outcome Measure(s) Implantation rate (IR) and live birth rate (LBR) according to the number of multinucleated blastomeres at the two-cell stage: none (Without-…
Non-parametric approaches to the impact of Holstein heifer growth from birth to insemination on their dairy performance at lactation one
2012
SUMMARYParametric approaches have been used widely to model animal growth and study the impact of growth profile on performance. Individual variation is often not considered in such approaches. However, non-parametric modelling allows this. Such an approach, based on spline functions, was used to study the importance of growth profiles from age 0 to 15 months (i.e. insemination) on milk yield and composition in primiparous cows. A dataset of 447 heifers was used for analysis of growth performance; 296 of them were also used to study impact on lactation. All of them originated from a French experimental herd and were born between 1986 and 2006. Clustering methods were also tested. Comparison…
The concept of genus within the family Phytoseiidae (Acari: Parasitiformes): historical review and phylogenetic analyses of the genus Neoseiulus Hugh…
2012
Systematic studies on the family Phytoseiidae were first conducted at the beginning of the 20th century but increased greatly after the Second World War. Various classifications have been proposed based on different characters such as: dorsal, ventral, and leg chaetotaxy; the shape of ventrianal and sternal shields; the shape of the insemination apparatus (spermatheca) and spermatodactylus; the number of teeth on the movable digit of chelicera; and dorsal and ventral adenotaxy. The genus concepts developed over the last five decades can be divided into two main categories or hypotheses. The first, supported mainly by Chant and McMurtry, focuses on dorsal and ventral chaetotaxy, and the gene…
La reproducción asistida y la filiación. Especial referencia al caso de las parejas de mujeres homosexuales
2018
This paper analyses, in general, the evolution that has had the art. 7.3 LTRHA since its introduction by the Act 3/2007, 15 march. In that way, it shows which has been the legislator´s solution about the use of assisted reproduction tecniques by homosexual women couples. Likewise, it studies which resolutions on the matter have been more relevant in the last years. All this, to set out the legislator´s failure and the need to reformulate the filiation regime in face of the challenge that assisted reproduction implies.
Personality characteristics analysis in couples undergoing artificial insemination
1994
The personality characteristics of 40 couples admitted into an artificial insemination scheme have been analysed. The personality study was carried out using Cattell's questionnaire 16 PF (form C) and EPI questionnaire (Eysenck Personality Inventory). The results show significant statistical differences between males and females with a greater conformity with the group, in women; women are also bolder and more disciplined from an emotional point of view, whereas men are more radical.
The transcriptome of spermatozoa used in homologous intrauterine insemination varies considerably between samples that achieve pregnancy and those th…
2009
Objective To differentiate transcripts' expression in the sperm from patients who achieved pregnancy in their first IUI cycle from those who did not. Basic sperm analysis is limited to forecasting pregnancies by means of assisted reproduction. New assays, such as microarray analysis, are potential predictive tools for this purpose. Design Nested case-control study. Setting University-affiliated private setting. Patient(s) Twenty sperm samples were obtained from infertile males undergoing their first IUI cycle with healthy partners. Sperm samples with which pregnancy was achieved (P; n=10) and those with which it was not achieved (NP; n=10) were identified and their respective messenger RNA …
Clinical success of intrauterine insemination cycles is affected by the sperm preparation time.
2013
Objective To determine the impact of the time interval from the end of sperm preparation (TSP) to intrauterine insemination (IUI) on the outcome. Design Prospective multicentre cohort study. Setting Seven French centers (assisted reproduction group in northeastern France, four academic centers, and three clinics). Patient(s) Eight hundred sixty-two IUI cycles (709 patients) managed by gonadotropins were studied. Intervention(s) Cycles were stimulated by either FSH or hMG, and hCG was administrated when the leading follicle diameter measured >15 mm. IUIs were performed ∼36 hours after ovulation triggering. Main Outcome Measure(s) Generalized linear mixed models for binary outcomes were used …
Improvements achieved in an oocyte donation program over a 10-year period: sequential increase in implantation and pregnancy rates and decrease in hi…
2006
Objective To compare outcome parameters and cumulative pregnancy rates (PRs) in oocyte donation cycles over a period of 10 years. Design Retrospective study. Setting University-affiliated assisted reproductive technology program. Patient(s) Women undergoing oocyte donation (10,537 cycles) between 1995 and 2005. Intervention(s) Ovarian stimulation and oocyte retrieval in donors. Embryo transfer performed in recipients after endometrial preparation. Main Outcome Measure(s) Outcome parameters and cumulative PRs were calculated and compared in relation to indication, age, and origin of sperm used. Result(s) Overall PR, implantation rate, clinical PR, and miscarriage rate per embryo transfer per…