| 1. |
- Abazajian, Kevork, et al.
(författare)
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CMB-S4 : Forecasting Constraints on Primordial Gravitational Waves
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 926:1
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Tidskriftsartikel (refereegranskat)abstract
- CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the universe. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semianalytic projection tool, targeted explicitly toward optimizing constraints on the tensor-to-scalar ratio, r, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2–3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments, given a desired scientific goal. To form a closed-loop process, we couple this semianalytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for r > 0.003 at greater than 5σ, or in the absence of a detection, of reaching an upper limit of r < 0.001 at 95% CL.
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| 2. |
- Ade, Peter, et al.
(författare)
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The Simons Observatory : science goals and forecasts
- 2019
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :2
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Tidskriftsartikel (refereegranskat)abstract
- The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial con figuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping approximate to 10% of the sky to a white noise level of 2 mu K-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of sigma(r) = 0.003. The large aperture telescope will map approximate to 40% of the sky at arcminute angular resolution to an expected white noise level of 6 mu K-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.
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| 3. |
- Averfalk, Helge, 1988-, et al.
(författare)
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Low-Temperature District Heating Implementation Guidebook : Final Report of IEA DHC Annex TS2. Implementation of Low-Temperature District Heating Systems
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This guidebook was written between 2018 and 2021 by seventeen authors that used approximately 15 000 hours of work within the IEA DHC TS2 annex. The content is based on more than 250 literature references and 165 inspiration initiatives to obtain lower temperatures in buildings and heat distribution networks. The author group wrote 40 internal documents about early implementations of low-temperature district heating. Fifteen of these early implementations are presented in this guidebook.The guidebook contains aggregated information about the main economic drivers for low-temperature district heating. It shows how to obtain lower temperatures in heating systems inside existing and new buildings, as well as in existing and new heat distribution networks. An applied study of a campus system in Darmstadt shows the possibility of reducing temperatures in an existing heat distribution network with rather high temperatures. The competitiveness of low-temperature district heating is explored by analysing business models and heat distribution costs. Early adopters of low-temperature district heating are presented by examples and by identified transition strategies. Five groups of network configurations with fourteen variants are presented to be used for low-temperature district heating. Finally, all 165 identified inspiration initiatives and all 137 locations mentioned are listed.
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| 4. |
- Cornelissen, Johannes H C, et al.
(författare)
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Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes
- 2007
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 10:7, s. 619-627
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Tidskriftsartikel (refereegranskat)abstract
- Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition. Here, we present the first quantitative analysis of the major climate-change-related drivers of litter decomposition rates in cold northern biomes worldwide.Leaf litters collected from the predominant species in 33 global change manipulation experiments in circum-arctic-alpine ecosystems were incubated simultaneously in two contrasting arctic life zones. We demonstrate that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species. Specifically, the ongoing warming-induced expansion of shrubs with recalcitrant leaf litter across cold biomes would constitute a negative feedback to global warming. Depending on the strength of other (previously reported) positive feedbacks of shrub expansion on soil carbon turnover, this may partly counteract direct warming enhancement of litter decomposition.
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| 5. |
- Farinotti, Daniel, et al.
(författare)
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How accurate are estimates of glacier ice thickness? Results from ITMIX, the Ice Thickness Models Intercomparison eXperiment
- 2017
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Ingår i: The Cryosphere. - : Copernicus GmbH. - 1994-0416 .- 1994-0424. ; 11, s. 949-970
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge of the ice thickness distribution of glaciers and ice caps is an important prerequisite for many glaciological and hydrological investigations. A wealth of approaches has recently been presented for inferring ice thickness from characteristics of the surface. With the Ice Thickness Models Intercomparison eXperiment (ITMIX) we performed the first coordinated assessment quantifying individual model performance. A set of 17 different models showed that individual ice thickness estimates can differ considerably – locally by a spread comparable to the observed thickness. Averaging the results of multiple models, however, significantly improved the results: on average over the 21 considered test cases, comparison against direct ice thickness measurements revealed deviations on the order of 10 ± 24 % of the mean ice thickness (1σ estimate). Models relying on multiple data sets – such as surface ice velocity fields, surface mass balance, or rates of ice thickness change – showed high sensitivity to input data quality. Together with the requirement of being able to handle large regions in an automated fashion, the capacity of better accounting for uncertainties in the input data will be a key for an improved next generation of ice thickness estimation approaches.
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| 6. |
- Gambadauro, Pietro, et al.
(författare)
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Endometrial cancer in a woman undergoing hysteroscopy for recurrent IVF failure
- 2017
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Ingår i: Gynecological Surgery. - : Springer Science and Business Media LLC. - 1613-2076 .- 1613-2084. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- AbstractBackground: Hysteroscopy, despite being the undisputed gold standard for the examination of the uterine cavity, is controversial as a routine procedure in infertile women. However, benign intrauterine conditions are common in women suffering repeated in vitro fertilization (IVF) failure, and growing evidence suggests a unique diagnostic and therapeutic role for hysteroscopy. Endometrial malignancy, on the contrary, is unreported by large published series of women with repeated IVF failures undergoing hysteroscopy, and its impact on fertility, for obvious reasons, has not been studied. Results: An unsuspected endometrial cancer was diagnosed in an asymptomatic 38-year-old woman undergoing hysteroscopy because of several repeated failures of in vitro fertilization and embryo transfer. Conclusions: Endometrial cancer can be found at hysteroscopy in young women with repeated IVF failures. The possibility of repeatedly unsuccessful fertility treatments should be taken into account when counseling infertile women about conservative treatment of endometrial cancer.
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| 7. |
- Gambadauro, Pietro, et al.
(författare)
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Intrauterine Adhesions following Conservative Treatment of Uterine Fibroids
- 2012
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Ingår i: Obstetrics and Gynecology International. - : Hindawi Limited. - 1687-9589 .- 1687-9597. ; 2012
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Tidskriftsartikel (refereegranskat)abstract
- Uterine fibroids are common in women of reproductive age and various conservative treatments are available. In order to achieve a successful conservative treatment of fibroids, functional integrity of the uterus is as important as tumor removal or symptoms relief. In this context, intrauterine adhesions must be recognized as a possible complication of conservative management of uterine fibroids, but diagnostic pitfalls might justify an underestimation of their incidence. Hysteroscopic myomectomy can cause adhesions as a result of surgical trauma to the endometrium. The average reported incidence is around 10% at second-look hysteroscopy, but it is higher in certain conditions, such as the case of multiple, apposing fibroids. Transmural myomectomies also have the potential for adhesion, especially when combined with uterine ischemia. Uterine arteries embolization also carries a risk of intracavitary adhesions. Prevention strategies including bipolar resection, barrier gel or postoperative estradiol, might be useful, but stronger evidence is needed. In view of current knowledge, we would recommend a prevention strategy based on a combination of surgical trauma minimization and identification of high-risk cases. Early hysteroscopic diagnosis and lysis possibly represents the best means of secondary prevention and treatment of postoperative intrauterine adhesions.
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| 8. |
- Iliadis, Stavros, et al.
(författare)
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Pelvic abscess following frozen embryo transfer
- 2013
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Ingår i: Journal of Obstetrics and Gynaecology. - : Informa UK Limited. - 0144-3615 .- 1364-6893. ; 33:6, s. 633-
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Tidskriftsartikel (refereegranskat)
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| 9. |
- Kowaluk, Miroslaw, et al.
(författare)
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A path cover technique for LCAs in dags
- 2008
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Ingår i: Algorithm theory – SWAT 2008 / Lecture notes in computer science. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0302-9743 .- 1611-3349. - 9783540699002 ; 5124, s. 222-223
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Konferensbidrag (refereegranskat)abstract
- As a second major result we show how to combine the path cover technique with LCA solutions for dags with small depth [9]. Our algorithm attains the best known upper time bound for this problem of O(n 2.575). However, most notably, the algorithm performs better on a vast amount of input dags, i.e. dags that do not have an almost linear-sized subdag of extremely regular structure. Finally, we apply our technique to improve the general upper time bounds on the worst case time complexity for the problem of reporting LCAs for each triple of vertices recently established by Yuster[26].
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| 10. |
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