3,509 research outputs found

    Having a baby in your 40s with ART: the reproductive dilemma of autologous versus donor oocytes.

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    BACKGROUND:Increasing numbers of women ≥40 years old are accessing assisted reproductive technology (ART) due to age-related infertility. There is limited population-based evidence about the impact on the cumulative live birth rate (CLBR) of women aged ≥40 years using their own oocytes, compared to women of a similar age, using donor oocytes. AIMS:To compare the CLBR for women ≥40 years undergoing ART using autologous oocytes and women of similar age using donor oocytes. MATERIALS AND METHODS:This population-based retrospective cohort study used data from all women aged ≥40 years undergoing ART with donated (n = 987) or autologous oocytes (n = 19 170) in Victoria, Australia between 2009 and 2016. A discrete-time survival model was used to evaluate the CLBR following ART with donor or autologous oocytes. The odds ratio, adjusted for woman's age; male age; parity; cause of infertility; and the associated 95% confidence intervals (CI), were calculated. The numbers needed to be exposed (NNEs) were calculated from the adjusted odds ratio (aOR) and the CLBR in the autologous group. RESULTS:The CLBR ranged from 28.6 to 42.5% in the donor group and from 12.5% to 1.4% in the autologous group. The discrete-time survival analysis with 95% CI demonstrated significant aOR on CLBR across all ages (range aOR: 2.56, 95% CI: 1.62-4.01 to aOR: 15.40, 95% CI: 9.10-26.04). CONCLUSIONS:Women aged ≥40 years, using donor oocytes had a significantly higher CLBR than women using autologous oocytes. The findings can be used when counselling women ≥40 years about their ART treatment options and to inform public policy

    Oocyte donor age has a significant impact on oocyte recipients' cumulative live-birth rate: a population-based cohort study

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    © 2019 Objective: To study the impact of the donor's and recipient's age on the cumulative live-birth rate (CLBR) in oocyte donation cycles. Design: A population-based retrospective cohort study. Setting: Not applicable. Patient(s): All women using donated oocytes (n = 1,490) in Victoria, Australia, between 2009 and 2015. Intervention(s): None. Main Outcome Measure(s): The association between the donor's and recipient's age and CLBR modeled by multivariate Cox proportional hazard regression with the covariates of male partner's age, recipient parity, and cause of infertility adjusted for, and donor age grouped as <30, 30–34, 35–37, 38–40, and ≥41 years, and recipient age as <35, 35–37, 38–40, 41–42, 43–44, and ≥45 years. Result(s): The mean age of the oocyte donors was 33.7 years (range: 21 to 45 years) with 49% aged 35 years and over. The mean age of the oocyte recipients was 41.4 years (range: 19 to 53 years) with 25.4% aged ≥45 years. There was a statistically significant relationship between the donor's age and the CLBR. The CLBR for recipients with donors aged <30 years and 30–34 years was 44.7% and 43.3%, respectively. This decreased to 33.6% in donors aged 35–37 years, 22.6% in donors aged 38–40 years, and 5.1% in donors aged ≥41 years. Compared with recipients with donors aged <30 years, the recipients with donors aged 38–40 years had 40% less chance of achieving a live birth (adjusted hazard ratio 0.60; 95% CI, 0.43–0.86) and recipients with donors aged ≥41 years had 86% less chance of achieving a live birth (adjusted hazard ratio 0.14; 95% CI, 0.04–0.44). The multivariate analysis showed no statistically significant effect of the recipient's age on CLBR. Conclusion(s): We have demonstrated that the age of the oocyte donor is critical to the CLBR and is independent of the recipient woman's age. Recipients using oocytes from donors aged ≥35 years had a statistically significantly lower CLBR when compared with recipients using oocytes from donors aged <35 years

    The Effect of Dust and Surface Roughness on the Efficiency of Solid Coupled Wheel Probes

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    Recent improvements in the performance of solid coupled wheel probes and other solid coupled ultrasonic devices [1] have opened up the possibility of their wider application. If such devices are to become general purpose NDE tools then it is important that the parameters which limit their use be understood. Experience gained at Imperial College by using such devices on real engineering structures indicated that the presence of high surface roughness and dust/dirt severely affected their performance. It is the aim of this paper to quantify these effects and gain a better understanding of their origins. This increased understanding will then allow for improved design of dry coupled devices

    GPURepair: Automated Repair of GPU Kernels

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    This paper presents a tool for repairing errors in GPU kernels written in CUDA or OpenCL due to data races and barrier divergence. Our novel extension to prior work can also remove barriers that are deemed unnecessary for correctness. We implement these ideas in our tool called GPURepair, which uses GPUVerify as the verification oracle for GPU kernels. We also extend GPUVerify to support CUDA Cooperative Groups, allowing GPURepair to perform inter-block synchronization for CUDA kernels. To the best of our knowledge, GPURepair is the only tool that can propose a fix for intra-block data races and barrier divergence errors for both CUDA and OpenCL kernels and the only tool that fixes inter-block data races for CUDA kernels. We perform extensive experiments on about 750 kernels and provide a comparison with prior work. We demonstrate the superiority of GPURepair through its capability to fix more kernels and its unique ability to remove redundant barriers and handle inter-block data races.Comment: 19 pages, 1 algorithm, 3 figures, 22nd International Conference on Verification Model Checking and Abstract Interpretation (VMCAI 2021

    Human Visual Search Does Not Maximize the Post-Saccadic Probability of Identifying Targets

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    Researchers have conjectured that eye movements during visual search are selected to minimize the number of saccades. The optimal Bayesian eye movement strategy minimizing saccades does not simply direct the eye to whichever location is judged most likely to contain the target but makes use of the entire retina as an information gathering device during each fixation. Here we show that human observers do not minimize the expected number of saccades in planning saccades in a simple visual search task composed of three tokens. In this task, the optimal eye movement strategy varied, depending on the spacing between tokens (in the first experiment) or the size of tokens (in the second experiment), and changed abruptly once the separation or size surpassed a critical value. None of our observers changed strategy as a function of separation or size. Human performance fell far short of ideal, both qualitatively and quantitatively

    Stochastic Species Turnover and Stable Coexistence in a Species-Rich, Fire-Prone Plant Community

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    Understanding the mechanisms that maintain diversity is important for managing ecosystems for species persistence. Here we used a long-term data set to understand mechanisms of coexistence at the local and regional scales in the Cape Floristic Region, a global hotspot of plant diversity. We used a dataset comprising 81 monitoring sites, sampled in 1966 and again in 1996, and containing 422 species for which growth form, regeneration mode, dispersal distance and abundances at both the local (site) and meta-community scales are known. We found that species presence and abundance were stable at the meta-community scale over the 30 year period but highly unstable at the local scale, and were not influenced by species' biological attributes. Moreover, rare species were no more likely to go extinct at the local scale than common species, and that alpha diversity in local communities was strongly influenced by habitat. We conclude that stochastic environmental fluctuations associated with recurrent fire buffer populations from extinction, thereby ensuring stable coexistence at the meta-community scale by creating a “neutral-like” pattern maintained by niche-differentiation

    A comprehensive database of quality-rated fossil ages for Sahul's Quaternary vertebrates.

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    The study of palaeo-chronologies using fossil data provides evidence for past ecological and evolutionary processes, and is therefore useful for predicting patterns and impacts of future environmental change. However, the robustness of inferences made from fossil ages relies heavily on both the quantity and quality of available data. We compiled Quaternary non-human vertebrate fossil ages from Sahul published up to 2013. This, the FosSahul database, includes 9,302 fossil records from 363 deposits, for a total of 478 species within 215 genera, of which 27 are from extinct and extant megafaunal species (2,559 records). We also provide a rating of reliability of individual absolute age based on the dating protocols and association between the dated materials and the fossil remains. Our proposed rating system identified 2,422 records with high-quality ages (i.e., a reduction of 74%). There are many applications of the database, including disentangling the confounding influences of hypothetical extinction drivers, better spatial distribution estimates of species relative to palaeo-climates, and potentially identifying new areas for fossil discovery
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