35 research outputs found

    ABORAS: polarimetric, 10cm/s RV observations of the Sun as a star

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    We present a description of A dual-Beam pOlarimetric Robotic Aperture for the Sun (ABORAS), to serve as a Solar input with a dedicated Stokes V polarimeter for the HARPS3 high-resolution spectrograph. ABORAS has three main science drivers: trying to understand the physics behind stellar variability, tracking the long-term stability of HARPS3, and serve as a benchmark for Earth-sized exoplanet detection with HARPS3 by injecting an Earth RV signal into the data. By design, ABORAS will (together with the HARPS3 instrument) be able to measure 10cm/s variations in RV of the integrated Solar disk and detect integrated magnetic field levels at sub 1 Gauss level through circularly polarized light.Comment: 8 pages, 5 figures, SPIE Proceedings pre-print, draft version

    Gravity-darkening Analysis of the Misaligned Hot Jupiter MASCARA-4 b

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    MASCARA-4 b is a hot Jupiter in a highly misaligned orbit around a rapidly rotating A3V star that was observed for 54 days by the Transiting Exoplanet Survey Satellite (TESS). We perform two analyses of MASCARA-4 b using a stellar gravity-darkened model. First, we measure MASCARA-4 b's misaligned orbital configuration by modeling its TESS photometric light curve. We take advantage of the asymmetry in MASCARA-4 b's transit due to its host star's gravity-darkened surface to measure MASCARA-4 b's true spin–orbit angle to be 104°+7°-13°. We also detect a ~4σ secondary eclipse at 0.491 ± 0.007 orbital phase, proving that the orbit is slightly eccentric. Second, we model MASCARA-4 b's insolation including gravity darkening and find that the planet's received X-ray and ultraviolet flux varies by 4% throughout its orbit. MASCARA-4 b's short-period, polar orbit suggests that the planet likely underwent dramatic orbital evolution to end up in its present-day configuration and that it receives a varying stellar irradiance that perpetually forces the planet out of thermal equilibrium. These findings make MASCARA-4 b an excellent target for follow-up characterization to better understand the orbital evolution and present-day environment of planets around high-mass stars

    Rationale and design of the HepZero study: a prospective, multicenter, international, open, randomized, controlled clinical study with parallel groups comparing heparin-free dialysis with heparin-coated dialysis membrane (Evodial) versus standard care: study protocol for a randomized controlled trial

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    BACKGROUND: Anticoagulation for chronic dialysis patients with contraindications to heparin administration is challenging. Current guidelines state that in patients with increased bleeding risks, strategies that can induce systemic anticoagulation should be avoided. Heparin-free dialysis using intermittent saline flushes is widely adopted as the method of choice for patients at risk of bleeding, although on-line blood predilution may also be used. A new dialyzer, Evodial (Gambro, Lund, Sweden), is grafted with unfractionated heparin during the manufacturing process and may allow safe and efficient heparin-free hemodialysis sessions. In the present trial, Evodial was compared to standard care with either saline flushes or blood predilution. METHODS: The HepZero study is the first international (seven countries), multicenter (10 centers), randomized, controlled, open-label, non-inferiority (and if applicable subsequently, superiority) trial with two parallel groups, comprising 252 end-stage renal disease patients treated by maintenance hemodialysis for at least 3 months and requiring heparin-free dialysis treatments. Patients will be treated during a maximum of three heparin-free dialysis treatments with either saline flushes or blood predilution (control group), or Evodial. The first heparin-free dialysis treatment will be considered successful when there is: no complete occlusion of air traps or dialyzer rendering dialysis impossible; no additional saline flushes to prevent clotting; no change of dialyzer or blood lines because of clotting; and no premature termination (early rinse-back) because of clotting. The primary objectives of the study are to determine the effectiveness of the Evodial dialyzer, compared with standard care in terms of successful treatments during the first heparin-free dialysis. If the non-inferiority of Evodial is demonstrated then the superiority of Evodial over standard care will be tested. The HepZero study results may have major clinical implications for patient care. TRIAL REGISTRATION: ClinicalTrials.gov NCT0131848

    PPARaplha L162V polymorphism alters the potential of N-3 fatty acids to increase lipoprotein lipase activity

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    Omega‐3 fatty acids (FAs) may accelerate plasma triglyceride (TG) clearance by altering lipoprotein lipase (LPL) activity. Yet, the ability of n‐3 FAs to increase LPL activity is dependent on transcription factors such as peroxisome proliferator‐activated receptor alpha (PPARα). The objective was to examine the effects of n‐3 FAs on LPL activity considering the occurrence of PPAR α L162V polymorphism. First, 14 pairs of men either L162 homozygotes or carriers of the V162 allele were supplemented with n‐3 FAs. Second, transient transfections in HepG2 cells, for the L162‐ and V162‐PPARα variants with the peroxisome proliferator‐response element from the human LPL gene, were transactivated with n‐3 FAs. In vivo results demonstrate that the LPL activity increased non‐significantly by 14.4% in L162 homozygotes compared with 6.6% in carriers of the PPAR α‐V162 allele, after n‐3 FA supplementation. Additionally, the L162 homozygotes tended towards an inverse correlation between LPL activities and plasma TG levels. Conversely, carriers of the V162 allele showed no such relationship. In vitro data demonstrates that transcription rates of LPL tended to be higher for the L162‐PPARα than V162‐PPARα after n‐3 FAs activation. Overall, these results indicate that n‐3 FA supplementation increases the transcription rate of LPL to a greater extent in L162‐PPARα than V162‐PPARα

    Effect of the PPAR-Alpha L162V polymorphism on the cardiovascular disease risk factor in response to n–3 polyunsaturated fatty acids

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    Background: Dietary n–3 polyunsaturated fatty acids (PUFAs) decrease the risk of cardiovascular disease (CVD). Yet, genetic variations of the gene encoding the peroxisome proliferator-activated receptor- (PPAR ) can also modulate CVD risk factors. Since fatty acids, including n–3 PUFAs, are natural ligands of PPAR , a gene-diet interaction effect could be observed. Aims: To examine whether n–3 PUFAinduced changes in CVD risk factors are influenced by the PPAR L162V polymorphism. Methods: Fourteen men, carriers of the V162 allele and 14 L162 homozygotes, were matched according to age and body mass index. Subjects followed, for 8 weeks, a low-fat diet and then were supplemented daily with 5 g of fish oil for 6 weeks. Results: Baseline characteristics were similar for both genotype groups. Independently of the genotype, the supplementation was associated with a significant decrease in plasma triacylglycerol and fasting glucose concentrations, diastolic blood pressure, and with an increase in total apolipoprotein B concentrations. The extent of the decrease in plasma triacylglycerol concentrations was comparable for both genotype groups (p ! 0.03). A significant genotype-by-diet interaction effect was observed for plasma C-reactive protein concentrations (p = 0.01). Conclusions: The PPAR L162V polymorphism may contribute to the interindividual variability in the CVD risk factor response to n–3 PUFAs

    VNtyper enables accurate alignment-free genotyping of MUC1 coding VNTR using short-read sequencing data in autosomal dominant tubulointerstitial kidney disease

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    Summary: The human genome comprises approximately 3% of tandem repeats with variable length (VNTR), a few of which have been linked to human rare diseases. Autosomal dominant tubulointerstitial kidney disease—MUC1 (ADTKD-MUC1) is caused by specific frameshift variants in the coding VNTR of the MUC1 gene. Calling variants from VNTR using short-read sequencing (SRS) is challenging due to poor read mappability. We developed a computational pipeline, VNtyper, for reliable detection of MUC1 VNTR pathogenic variants and demonstrated its clinical utility in two distinct cohorts: (1) a historical cohort including 108 families with ADTKD and (2) a replication naive cohort comprising 2,910 patients previously tested on a panel of genes involved in monogenic renal diseases. In the historical cohort all cases known to carry pathogenic MUC1 variants were re-identified, and a new 25bp-frameshift insertion in an additional mislaid family was detected. In the replication cohort, we discovered and validated 30 new patients
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