85 research outputs found

    The acceleration of superrotation in simulated hot Jupiter atmospheres

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordContext. Atmospheric superrotating flows at the equator are a nearly ubiquitous result when conducting simulations of hot Jupiters. One theory explaining how this zonally-coherent flow reaches equilibrium has already been developed in the literature. This understanding, however, relies on the existence of either an initial superrotating flow or a sheared flow, coupled with a slow evolution that permits a linear steady state to be reached. Aims. A consistent physical understanding of superrotation is needed for arbitrary drag and radiative timescales, along with the relevance of taking linear steady states into account, needs to be assessed. Methods. We obtained an analytical expression for the structure, frequency, and decay rate of propagating waves in hot Jupiter atmospheres around a state at rest in the 2D shallow-water β–plane limit. We solved this expression numerically and confirmed the robustness of our results with a 3D linear wave algorithm. We then compared it with 3D simulations of hot Jupiter atmospheres and studied the nonlinear momentum fluxes. Results. We show that under strong day-night heating, the dynamics do not transit through a linear steady state when starting from an initial atmosphere in solid body rotation. We further demonstrate that non–linear effects favor the initial spin-up of superrotation and that acceleration due to the vertical component of the eddy–momentum flux is critical to the initial development of superrotation . Conclusions. We describe the initial phases of the acceleration of superrotation, including the consideration of differing radiative and drag timescales, and we conclude that eddy-momentum-driven superrotating equatorial jets are robust, physical phenomena in simulations of hot Jupiter atmospheres.Leverhulme TrustScience and Technology Facilities Counci

    Wapiti\texttt{Wapiti}: a data-driven approach to correct for systematics in RV data -- Application to SPIRou data of the planet-hosting M dwarf GJ 251

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    Context: Recent advances in the development of precise radial velocity (RV) instruments in the near-infrared (nIR) domain, such as SPIRou, have facilitated the study of M-type stars to more effectively characterize planetary systems. However, the nIR presents unique challenges in exoplanet detection due to various sources of planet-independent signals which can result in systematic errors in the RV data. Aims: In order to address the challenges posed by the detection of exoplanetary systems around M-type stars using nIR observations, we introduce a new data-driven approach for correcting systematic errors in RV data. The effectiveness of this method is demonstrated through its application to the star GJ 251. Methods: Our proposed method, referred to as Wapiti\texttt{Wapiti} (Weighted principAl comPonent analysIs reconsTructIon), uses a dataset of per-line RV time-series generated by the line-by-line (LBL) algorithm and employs a weighted principal component analysis (wPCA) to reconstruct the original RV time-series. A multi-step process is employed to determine the appropriate number of components, with the ultimate goal of subtracting the wPCA reconstruction of the per-line RV time-series from the original data in order to correct systematic errors. Results: The application of Wapiti\texttt{Wapiti} to GJ 251 successfully eliminates spurious signals from the RV time-series and enables the first detection in the nIR of GJ 251b, a known temperate super-Earth with an orbital period of 14.2 days. This demonstrates that, even when systematics in SPIRou data are unidentified, it is still possible to effectively address them and fully realize the instrument's capability for exoplanet detection. Additionally, in contrast to the use of optical RVs, this detection did not require to filter out stellar activity, highlighting a key advantage of nIR RV measurements.Comment: Submitted to A&A. For the publicly available Wapiti code, see https://github.com/HkmMerwan/wapit

    First-trimester cesarean scar pregnancy: a comparative analysis of treatment options from the international registry

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    Background: A cesarean scar pregnancy is an iatrogenic consequence of a previous cesarean delivery. The gestational sac implants into a niche created by the incision of the previous cesarean delivery, and this carries a substantial risk for major maternal complications. The aim of this study was to report, analyze, and compare the effectiveness and safety of different treatments options for cesarean scar pregnancies managed in the first trimester through a registry. Objective: This study aimed to evaluated the ultrasound findings, disease behavior, and management of first-trimester cesarean scar pregnancies. Study design: We created an international registry of cesarean scar pregnancy cases to study the ultrasound findings, disease behavior, and management of cesarean scar pregnancies. The Cesarean Scar Pregnancy Registry collects anonymized ultrasound and clinical data of individual patients with a cesarean scar pregnancy on a secure, digital information platform. Cases were uploaded by 31 participating centers across 19 countries. In this study, we only included live and failing cesarean scar pregnancies (with or without a positive fetal heart beat) that received active treatment (medical or surgical) before 12+6 weeks' gestation to evaluate the effectiveness and safety of the different management options. Patients managed expectantly were not included in this study and will be reported separately. Treatment was classified as successful if it led to a complete resolution of the pregnancy without the need for any additional medical interventions. Results: Between August 29, 2018, and February 28, 2023, we recorded 460 patients with cesarean scar pregnancies (281 live, 179 failing cesarean scar pregnancy) who fulfilled the inclusion criteria and were registered. A total of 270 of 460 (58.7%) patients were managed surgically, 123 of 460 (26.7%) patients underwent medical management, 46 of 460 (10%) patients underwent balloon management, and 21 of 460 (4.6%) patients received other, less frequently used treatment options. Suction evacuation was very effective with a success rate of 202 of 221 (91.5%; 95% confidence interval, 87.8-95.2), whereas systemic methotrexate was least effective with only 38 of 64 (59.4%; 95% confidence interval, 48.4-70.4) patients not requiring additional treatment. Overall, surgical treatment of cesarean scar pregnancies was successful in 236 of 258 (91.5%, 95% confidence interval, 88.4-94.5) patients and complications were observed in 24 of 258 patients (9.3%; 95% confidence interval, 6.6-11.9). Conclusion: A cesarean scar pregnancy can be managed effectively in the first trimester of pregnancy in more than 90% of cases with either suction evacuation, balloon treatment, or surgical excision. The effectiveness of all treatment options decreases with advancing gestational age, and cesarean scar pregnancies should be treated as early as possible after confirmation of the diagnosis. Local medical treatment with potassium chloride or methotrexate is less efficient and has higher rates of complications than the other treatment options. Systemic methotrexate has a substantial risk of failing and a higher complication rate and should not be recommended as first-line treatment

    ANDES, the high resolution spectrograph for the ELT: science case, baseline design and path to construction

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    Prognostic factors in prostate cancer

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    Prognostic factors in organ confined prostate cancer will reflect survival after surgical radical prostatectomy. Gleason score, tumour volume, surgical margins and Ki-67 index have the most significant prognosticators. Also the origins from the transitional zone, p53 status in cancer tissue, stage, and aneuploidy have shown prognostic significance. Progression-associated features include Gleason score, stage, and capsular invasion, but PSA is also highly significant. Progression can also be predicted with biological markers (E-cadherin, microvessel density, and aneuploidy) with high level of significance. Other prognostic features of clinical or PSA-associated progression include age, IGF-1, p27, and Ki-67. In patients who were treated with radiotherapy the survival was potentially predictable with age, race and p53, but available research on other markers is limited. The most significant published survival-associated prognosticators of prostate cancer with extension outside prostate are microvessel density and total blood PSA. However, survival can potentially be predicted by other markers like androgen receptor, and Ki-67-positive cell fraction. In advanced prostate cancer nuclear morphometry and Gleason score are the most highly significant progression-associated prognosticators. In conclusion, Gleason score, capsular invasion, blood PSA, stage, and aneuploidy are the best markers of progression in organ confined disease. Other biological markers are less important. In advanced disease Gleason score and nuclear morphometry can be used as predictors of progression. Compound prognostic factors based on combinations of single prognosticators, or on gene expression profiles (tested by DNA arrays) are promising, but clinically relevant data is still lacking

    A First Step Towards an Intelligent Integrated Design System in the Building Field

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    This article presents the work the Knowledge Base Group is achieving towards the integration of Artificial Intelligence based facilities in the Building design process. After an overview of the current state of the integrated design process, the context and the technical guidelines to realize computer integrated software in the building design field is described. Then some tools are presented to model the knowledge (the HBDS method) and to implement such model in our Mips home-made knowledge modelling software platform (including object-oriented database management facilities, expert system reasoning facilities, hypertext edition facilities, 3D-design and 3D-view modules...). Finally the authors describe the Quakes application devoted to assess detached house anti-seismic capabilities during the design process. A deep conceptual model considers all the semantic entities (columns, resistant panels, openings,...) involved in the anti-seismic expertise. Using both this conceptual model description of a detached house and the 3D design tool, they input the project. Then the seismic expertise is driven in a divide and conquer approach and records the alleged configuration recognized automatically linked to the corresponding section of the building regulatio

    Spurenanalyse von Ca in St�uben und Aerosolen

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    Absorption of glycine irrigating solution during endoscopic transanal resection of rectal tumors.

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    PURPOSE: This study was undertaken to evaluate the potential metabolic complications of 1.5 percent glycine irrigating solution during endoscopic transanal resection (ETAR) of rectal tumors. METHODS: Thirteen consecutive frail patients (mean age, 81 (range, 57-91) years) undergoing 18 ETAR were prospectively studied from July 1993 to January 1995. Indications for ETAR included palliation of advanced rectal cancer (12 patients) and an extensive villous tumor (1 patient). A 27-French two-way Iglesias resectoscope was used. Packed cell volume, blood glucose, and serum concentrations of sodium, potassium, and creatinine were measured before, during (at 45 minutes), and after (at 6 and 24 hours) ETAR. Plasma concentration of glycine and hemoglobin levels were both measured preoperatively and at 45 minutes and 24 hours, respectively. Variables studied included resection time, volume and rate of irrigating fluid, height of irrigating fluid bag above operating table, resectate weight, occurrence of intraperitoneal and extraperitoneal perforation, blood loss, and clinical symptoms. RESULTS: Two patients were excluded. Mean operating time was 456 minutes. A mean of 192.3 liters of irrigant was infused into the rectum. Mean irrigation rate was 43,330 ml/minutes. Mean height of irrigating fluid bag was 692 cm. Extraperitoneal perforation occurred in two patients. Blood loss exceeded 200 ml in four patients, one of whom complained of nausea (operating time, 110 minutes). Mean rise in p-glycine at 45 minutes (10,028 mol/l; 387 percent of preoperative values) was significant (P = 0.006). Changes in packed cell volume, b-hemoglobin, b-glucose, s-sodium, and s-creatinine levels were not significant. There was significant correlation between p-glycine and s-creatinine levels at six hours (P = 0.033), between p-glycine levels and fall in s-sodium at 24 hours (P = 0.037), and between levels of b-hemoglobin and packed cell volume at 24 hours (P = 0.0004). There was a positive linear correlation between p-glycine and operating time (r = 0.7; P = 0.0026) and between p-glycine and volume of irrigating fluid (r = 0.5; P = 0.0386). CONCLUSIONS: Operating time best predicts increase of p-glycine in ETAR

    The common semantic model in GENIAL

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