High Resolution Imaging and the Formation of Stars and Planets

Understanding the formation of stellar and planetary systems is one of the great challenges of contemporary astrophysics. This thesis describes progress towards understanding these processes, through advancement of techniques to enable high resolution imaging of faint companions and other structures in the immediate environs of young stars. To ensure optimal performance in an era of large segmented telescopes, techniques to precisely cophase the mirror segments are required. In this thesis we propose the Fizeau Interferometric Cophasing of Segmented Mirrors algorithm, and present the results of testing both numerically and through experiment. We help to rectify a lack of observational evidence with which to test brown dwarf evolutionary models, by laying the foundation for an orbital monitoring survey of 19 brown dwarf binary systems and reporting the discovery of an additional 7 low mass companions to intermediate mass stars. We perform a Non-Redundant Masking (NRM) survey targeting the 1\,Myr old Ophiuchus star forming region. Both binary statistics and the relationship between multiplicity and the presence of a circumstellar disk are explored, providing many results similar to those from older regions. This helps frame the time evolution of effects related to dynamical interactions in binary systems, and the timescale of disk dissipation, with profound implications for giant planet formation. In thesis we also present the results of commissioning for the Gemini Planet Imager Non-Redundant Masking mode. These results indicate that the addition of an Extreme Adaptive Optics systems has substantially improved the performance of NRM compared to previous instruments. Finally, the transition disk T Cha is studied with multi-epoch NRM data, showing that the signal previously interpreted as a planetary companion is more likely to be the result of forward scattering from the inclined outer disk

Rational psychoactive drug selection

Item does not contain fulltextKUN Nijmegen, 05 juli 2000Promotores : Vries Robbé, P.F. de, Zitman, F.G., Tjandra-Maga, T.B.102 p

Archaeological communication and digital technology: Interview Transcript 19

This dataset is part of Sarah Colley's research project Mediated Messages: Archaeology Communication and Digital Technology (2010-2015) which investigates philosophical and ethical questions raised by using digital communication technology in archaeology and cultural heritage practice (e.g. Colley 2013, 2015). In 2011 Colley interviewed thirty Australian-based archaeologists and cultural heritage professionals about their use of digital technology and their communication with professional peers; television, radio and newspaper journalists; public relations and online media practitioners; public and government organisations; businesses; and members of the wider public including Indigenous community members and traditional owners. The research provides insights into e.g. remediation political economy, technology design, representation, authenticity and digital literacy. Changing communication technologies impact on peoples' understanding of and reactions to physical remains of the human past in ways that have broader social political and economic implications

Outcomes of beta blocker use in advanced hepatocellular carcinoma treated with immune checkpoint inhibitors

Background: In patients with cirrhosis, portal hypertension increases intestinal permeability, dysbiosis, and bacterial translocation, promoting an inflammatory state that can lead to the progression of liver disease and development of hepatocellular carcinoma (HCC). We aimed to investigate whether beta blockers (BBs), which can mediate portal hypertension, conferred survival benefits in patients treated with immune checkpoint inhibitors (ICIs). Methods: We conducted a retrospective, observational study of 578 patients with unresectable HCC treated with ICI from 2017 to 2019 at 13 institutions across three continents. BB use was defined as exposure to BBs at any time during ICI therapy. The primary objective was to assess the association of BB exposure with overall survival (OS). Secondary objectives were to evaluate the association of BB use with progression-free survival (PFS) and objective response rate (ORR) according to RECIST 1.1 criteria. Results: In our study cohort, 203 (35%) patients used BBs at any point during ICI therapy. Of these, 51% were taking a nonselective BB. BB use was not significantly correlated with OS (hazard ratio [HR] 1.12, 95% CI 0.9-1.39, P = 0.298), PFS (HR 1.02, 95% CI 0.83-1.26, P = 0.844) or ORR (odds ratio [OR] 0.84, 95% CI 0.54-1.31, P = 0.451) in univariate or multivariate analyses. BB use was also not associated with incidence of adverse events (OR 1.38, 95% CI 0.96-1.97, P = 0.079). Specifically, nonselective BB use was not correlated with OS (HR 0.94, 95% CI 0.66-1.33, P = 0.721), PFS (HR 0.92, 0.66-1.29, P = 0.629), ORR (OR 1.20, 95% CI 0.58-2.49, P = 0.623), or rate of adverse events (OR 0.82, 95% CI 0.46-1.47, P = 0.510). Conclusion: In this real-world population of patients with unresectable HCC treated with immunotherapy, BB use was not associated with OS, PFS or ORR

Assessment of Systemic and Gastrointestinal Tissue Damage Biomarkers for GVHD Risk Stratification.

We used a rigorous PRoBE (prospective-specimen collection, retrospective-blinded-evaluation) study design to compare the ability of biomarkers of systemic inflammation and biomarkers of gastrointestinal (GI) tissue damage to predict response to corticosteroid treatment, the incidence of clinically severe disease, 6-month nonrelapse mortality (NRM), and overall survival in patients with acute graft-versus-host disease (GVHD). We prospectively collected serum samples of newly diagnosed GVHD patients (n = 730) from 19 centers, divided them into training (n = 352) and validation (n = 378) cohorts, and measured TNFR1, TIM3, IL6, ST2, and REG3a via enzyme-linked immunosorbent assay. Performances of the 4 strongest algorithms from the training cohort (TNFR1 + TIM3, TNFR1 + ST2, TNFR1 + REG3a, and ST2 + REG3a) were evaluated in the validation cohort. The algorithm that included only biomarkers of systemic inflammation (TNFR1 + TIM3) had a significantly smaller area under the curve (AUC; 0.57) than the AUCs of algorithms that contained ≥1 GI damage biomarker (TNFR1 + ST2, 0.70; TNFR1 + REG3a, 0.73; ST2 + REG3a, 0.79; all P < .001). All 4 algorithms were able to predict short-term outcomes such as response to systemic corticosteroids and severe GVHD, but the inclusion of a GI damage biomarker was needed to predict long-term outcomes such as 6-month NRM and survival. The algorithm that included 2 GI damage biomarkers was the most accurate of the 4 algorithms for all endpoints.http://deepblue.lib.umich.edu/bitstream/2027.42/175358/2/Assessment of systemic and gastrointestinal tissue damage biomarkers for GVHD risk stratification.pdfPublished versionDescription of Assessment of systemic and gastrointestinal tissue damage biomarkers for GVHD risk stratification.pdf : Published versio