144 research outputs found

    Batch solution of small PDEs with the OPS DSL

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    In this paper we discuss the challenges and optimisations opportunities when solving a large number of small, equally sized discretised PDEs on regular grids. We present an extension of the OPS (Oxford Parallel library for Structured meshes) embedded Domain Specific Language, and show how support can be added for solving multiple systems, and how OPS makes it easy to deploy a variety of transformations and optimisations. The new capabilities in OPS allow to automatically apply data structure transformations, as well as execution schedule transformations to deliver high performance on a variety of hardware platforms. We evaluate our work on an industrially representative finance simulation on Intel CPUs, as well as NVIDIA GPUs

    BENCHOP–SLV: the BENCHmarking project in Option Pricing–Stochastic and Local Volatility problems

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    In the recent project BENCHOP–the BENCHmarking project in Option Pricing we found that Stochastic and Local Volatility problems were particularly challenging. Here we continue the effort by introducing a set of benchmark problems for this type of problems. Eight different methods targeted for the Stochastic Differential Equation (SDE) formulation and the Partial Differential Equation (PDE) formulation of the problem, as well as Fourier methods making use of the characteristic function, were implemented to solve these problems. Comparisons are made with respect to time to reach a certain error level in the computed solution for the different methods. The implemented Fourier method was superior to all others for the two problems where it was implemented. Generally, methods targeting the PDE formulation of the problem outperformed the methods for the SDE formulation. Among the methods for the PDE formulation the ADI method stood out as the best performing one

    Fertility preservation in boys : recent developments and new insights

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    BACKGROUND: Infertility is an important side effect of treatments used for cancer and other non-malignant conditions in males. This may be due to the loss of spermatogonial stem cells (SSCs) and/or altered functionality of testicular somatic cells (e.g. Sertoli cells, Leydig cells). Whereas sperm cryopreservation is the first-line procedure to preserve fertility in post-pubertal males, this option does not exist for prepubertal boys. For patients unable to produce sperm and at high risk of losing their fertility, testicular tissue freezing is now proposed as an alternative experimental option to safeguard their fertility. OBJECTIVE AND RATIONALE: With this review, we aim to provide an update on clinical practices and experimental methods, as well as to describe patient management inclusion strategies used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss. SEARCH METHODS: Based on the expertise of the participating centres and a literature search of the progress in clinical practices, patient management strategies and experimental methods used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss were identified. In addition, a survey was conducted amongst European and North American centres/networks that have published papers on their testicular tissue banking activity. OUTCOMES: Since the first publication on murine SSC transplantation in 1994, remarkable progress has been made towards clinical application: cryopreservation protocols for testicular tissue have been developed in animal models and are now offered to patients in clinics as a still experimental procedure. Transplantation methods have been adapted for human testis, and the efficiency and safety of the technique are being evaluated in mouse and primate models. However, important practical, medical and ethical issues must be resolved before fertility restoration can be applied in the clinic. Since the previous survey conducted in 2012, the implementation of testicular tissue cryopreservation as a means to preserve the fertility of prepubertal boys has increased. Data have been collected from 24 co-ordinating centres worldwide, which are actively offering testis tissue cryobanking to safeguard the future fertility of boys. More than 1033 young patients (age range 3 months to 18 years) have already undergone testicular tissue retrieval and storage for fertility preservation. LIMITATIONS, REASONS FOR CAUTION: The review does not include the data of all reproductive centres worldwide. Other centres might be offering testicular tissue cryopreservation. Therefore, the numbers might be not representative for the entire field in reproductive medicine and biology worldwide. The key ethical issue regarding fertility preservation in prepubertal boys remains the experimental nature of the intervention. WIDER IMPLICATIONS: The revised procedures can be implemented by the multi-disciplinary teams offering and/or developing treatment strategies to preserve the fertility of prepubertal boys who have a high risk of fertility loss.Peer reviewe

    ART in Europe, 2017: results generated from European registries by ESHRE

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    © The Author(s) 2021. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Study question: What are the data on ART and IUI cycles, and fertility preservation (FP) interventions reported in 2017 as compared to previous years, as well as the main trends over the years? Summary answer: The 21st ESHRE report on ART and IUI shows the continual increase in reported treatment cycle numbers in Europe, with a decrease in the proportion of transfers with more than one embryo causing an additional slight reduction of multiple delivery rates (DR) as well as higher pregnancy rates (PR) and DR after frozen embryo replacement (FER) compared to fresh IVF and ICSI cycles, while the number of IUI cycles increased and their outcomes remained stable. What is known already: Since 1997, ART aggregated data generated by national registries, clinics or professional societies have been gathered and analyzed by the European IVF-monitoring Consortium (EIM) and communicated in a total of 20 manuscripts published in Human Reproduction and Human Reproduction Open. Study design size duration: Data on European medically assisted reproduction (MAR) are collected by EIM for ESHRE on a yearly basis. The data on treatments performed between 1 January and 31 December 2017 in 39 European countries were provided by either National Registries or registries based on personal initiatives of medical associations and scientific organizations. Participants/materials setting methods: Overall, 1382 clinics offering ART services in 39 countries reported a total of 940 503 treatment cycles, including 165 379 with IVF, 391 379 with ICSI, 271 476 with FER, 37 303 with preimplantation genetic testing (PGT), 69 378 with egg donation (ED), 378 with IVM of oocytes, and 5210 cycles with frozen oocyte replacement (FOR). A total of 1273 institutions reported data on 207 196 IUI cycles using either husband/partner's semen (IUI-H; n = 155 794) or donor semen (IUI-D; n = 51 402) in 30 countries and 25 countries, respectively. Thirteen countries reported 18 888 interventions for FP, including oocyte, ovarian tissue, semen and testicular tissue banking in pre- and postpubertal patients. Main results and the role of chance: In 21 countries (20 in 2016) in which all ART clinics reported to the registry, 473 733 treatment cycles were registered for a total population of approximately 330 million inhabitants, allowing a best-estimate of a mean of 1435 cycles performed per million inhabitants (range: 723-3286).Amongst the 39 reporting countries, the clinical PR per aspiration and per transfer in 2017 were similar to those observed in 2016 (26.8% and 34.6% vs 28.0% and 34.8%, respectively). After ICSI the corresponding rates were also similar to those achieved in 2016 (24% and 33.5% vs 25% and 33.2% in 2016). When freeze all cycles were removed, the clinical PRs per aspiration were 30.8% and 27.5% for IVF and ICSI, respectively.After FER with embryos originating from own eggs the PR per thawing was 30.2%, which is comparable to 30.9% in 2016, and with embryos originating from donated eggs it was 41.1% (41% in 2016). After ED the PR per fresh embryo transfer was 49.2% (49.4% in 2016) and per FOR 43.3% (43.6% in 2016).In IVF and ICSI together, the trend towards the transfer of fewer embryos continues with the transfer of 1, 2, 3 and ≄4 embryos in 46.0%, 49.2%, 4.5% and in 0.3% of all treatments, respectively (corresponding to 41.5%, 51.9%. 6.2% and 0.4% in 2016). This resulted in a reduced proportion of twin DRs of 14.2% (14.9% in 2016) and stable triplet DR of 0.3%. Treatments with FER in 2017 resulted in a twin and triplet DR of 11.2% and 0.2%, respectively (vs 11.9% and 0.2% in 2016).After IUI, the DRs remained similar at 8.7% after IUI-H (8.9% in 2016) and at 12.4% after IUI-D (12.4.0% in 2016). Twin and triplet DRs after IUI-H were 8.1% and 0.3%, respectively (in 2016: 8.8% and 0.3%) and 6.9% and 0.2% after IUI-D (in 2016: 7.7% and 0.4%). Amongst 18 888 FP interventions in 13 countries, cryopreservation of ejaculated sperm (n = 11 112 vs 7877 from 11 countries in 2016) and of oocytes (n = 6588 vs 4907 from eight countries in 2016) were the most frequently reported. Limitations reasons for caution: As the methods of data collection and levels of reporting vary amongst European countries, interpretation of results should remain cautious. Some countries were unable to deliver data about the number of initiated cycles and deliveries. Wider implications of the findings: The 21st ESHRE report on ART, IUI and FP interventions shows a continuous increase of reported treatment numbers and MAR-derived livebirths in Europe. Being already the largest data collection on MAR in Europe, efforts should continue to optimize data collection and reporting with the perspective of improved quality control, transparency and vigilance in the field of reproductive medicine. Study funding/competing interests: The study has received no external funding and all costs are covered by ESHRE. There are no competing interests.info:eu-repo/semantics/publishedVersio

    ART in Europe, 2018 : results generated from European registries by ESHRE

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    STUDY QUESTION: What are the data and trends on ART and IUI cycle numbers and their outcomes, and on fertility preservation (FP) interventions, reported in 2018 as compared to previous years?SUMMARY ANSWER: The 22nd ESHRE report shows a continued increase in reported numbers of ART treatment cycles and children born in Europe, a decrease in transfers with more than one embryo with a further reduction of twin delivery rates (DRs) as compared to 2017, higher DRs per transfer after fresh IVF or ICSI cycles (without considering freeze-all cycles) than after frozen embryo transfer (FET) with higher pregnancy rates (PRs) after FET and the number of reported IUI cycles decreased while their PR and DR remained stable.WHAT IS KNOWN ALREADY: ART aggregated data generated by national registries, clinics or professional societies have been gathered and analysed by the European IVF-monitoring Consortium (EIM) since 1997 and reported in 21 manuscripts published in Human Reproduction and Human Reproduction Open.STUDY DESIGN, SIZE, DURATION: Data on medically assisted reproduction (MAR) from European countries are collected by EIM for ESHRE on a yearly basis. The data on treatment cycles performed between 1 January and 31 December 2018 were provided by either national registries or registries based on initiatives of medical associations and scientific organizations or committed persons of 39 countries.PARTICIPANTS/MATERIALS, SETTING, METHODS: Overall, 1422 clinics offering ART services in 39 countries reported a total of more than 1 million (1 007 598) treatment cycles for the first time, including 162 837 with IVF, 400 375 with ICSI, 309 475 with FET, 48 294 with preimplantation genetic testing, 80 641 with egg donation (ED), 532 with IVM of oocytes and 5444 cycles with frozen oocyte replacement (FOR). A total of 1271 institutions reported data on IUI cycles using either husband/partner’s semen (IUI-H; nÂŒ148 143) or donor semen (IUI-D; nÂŒ50 609) in 31 countries and 25 countries, respectively. Sixteen countries reported 20 994 interventions in pre- and post-pubertal patients for FP including oocyte, ovarian tissue, semen and testicular tissue banking.MAIN RESULTS AND THE ROLE OF CHANCE: In 21 countries (21 in 2017) in which all ART clinics reported to the registry, 410 190 treatment cycles were registered for a total population of 300 million inhabitants, allowing a best estimate of a mean of 1433 cycles performed per million inhabitants (range: 641–3549). Among the 39 reporting countries, for IVF, the clinical PR per aspiration slightly decreased while the PR per transfer remained similar compared to 2017 (25.5% and 34.1% in 2018 versus 26.8% and 34.3% in 2017). In ICSI, the corresponding rates showed similar evolutions in 2018 compared to 2017 (22.5% and 32.1% in 2018 versus 24.0% and 33.5% in 2017). When freeze-all cycles were not considered for the calculations, the clinical PRs per aspiration were 28.8% (29.4% in 2017) and 27.3% (27.3% in 2017) for IVF and ICSI, respectively. After FET with embryos originating from own eggs, the PR per thawing was 33.4% (versus 30.2% in 2017), and with embryos originating from donated eggs 41.8% (41.1% in 2017). After ED, the PR per fresh embryo transfer was 49.6% (49.2% in 2017) and per FOR 44.9% (43.3% in 2017). In IVF and ICSI together, the trend towards the transfer of fewer embryos continues with the transfer of 1, 2, 3 and 4 embryos in 50.7%, 45.1%, 3.9% and 0.3% of all treatments, respectively (corresponding to 46.0%, 49.2%. 4.5% and 0.3% in 2017). This resulted in a reduced proportion of twin DRs of 12.4% (14.2% in 2017) and similar triplet DR of 0.2%. Treatments with FET in 2018 resulted in twin and triplet DRs of 9.4% and 0.1%, respectively (versus 11.2% and 0.2%, respectively in 2017). After IUI, the DRs remained similar at 8.8% after IUI-H (8.7% in 2017) and at 12.6% after IUI-D (12.4% in 2017). Twin and triplet DRs after IUI-H were 8.4% and 0.3%, respectively (in 2017: 8.1% and 0.3%), and 6.4% and 0.2% after IUI-D (in 2017: 6.9% and 0.2%). Among 20 994 FP interventions in 16 countries (18 888 in 13 countries in 2017), cryopreservation of ejaculated sperm (nÂŒ10 503, versus 11 112 in 2017) and of oocytes (nÂŒ9123 versus 6588 in 2017) were the most frequently reported.LIMITATIONS, REASONS FOR CAUTION: The results should be interpreted with caution as data collection systems and completeness of reporting vary among European countries. Some countries were unable to deliver data about the number of initiated cycles and/or deliveries.WIDER IMPLICATIONS OF THE FINDINGS: The 22nd ESHRE data collection on ART, IUI and FP interventions shows a continuous increase of reported treatment numbers and MAR-derived livebirths in Europe. Although it is the largest data collection on MAR in Europe, further efforts towards optimization of both the collection and reporting, with the aim of improving surveillance and vigilance in the field of reproductive medicine, are awaited.STUDY FUNDING/COMPETING INTEREST(S): The study has received no external funding and all costs are covered by ESHRE. There are no competing interests.peer-reviewe

    Controversy and consensus on the management of elevated sperm DNA fragmentation in male infertility: a global survey, current guidelines, and expert recommendations

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    PURPOSE: Sperm DNA fragmentation (SDF) has been associated with male infertility and poor outcomes of assisted reproductive technology (ART). The purpose of this study was to investigate global practices related to the management of elevated SDF in infertile men, summarize the relevant professional society recommendations, and provide expert recommendations for managing this condition. MATERIALS AND METHODS: An online global survey on clinical practices related to SDF was disseminated to reproductive clinicians, according to the CHERRIES checklist criteria. Management protocols for various conditions associated with SDF were captured and compared to the relevant recommendations in professional society guidelines and the appropriate available evidence. Expert recommendations and consensus on the management of infertile men with elevated SDF were then formulated and adapted using the Delphi method. RESULTS: A total of 436 experts from 55 different countries submitted responses. As an initial approach, 79.1% of reproductive experts recommend lifestyle modifications for infertile men with elevated SDF, and 76.9% prescribe empiric antioxidants. Regarding antioxidant duration, 39.3% recommend 4-6 months and 38.1% recommend 3 months. For men with unexplained or idiopathic infertility, and couples experiencing recurrent miscarriages associated with elevated SDF, most respondents refer to ART 6 months after failure of conservative and empiric medical management. Infertile men with clinical varicocele, normal conventional semen parameters, and elevated SDF are offered varicocele repair immediately after diagnosis by 31.4%, and after failure of antioxidants and conservative measures by 40.9%. Sperm selection techniques and testicular sperm extraction are also management options for couples undergoing ART. For most questions, heterogenous practices were demonstrated. CONCLUSIONS: This paper presents the results of a large global survey on the management of infertile men with elevated SDF and reveals a lack of consensus among clinicians. Furthermore, it demonstrates the scarcity of professional society guidelines in this regard and attempts to highlight the relevant evidence. Expert recommendations are proposed to help guide clinicians
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