Tellus Institute

The Giant Magellan Telescope, with a 25.4m primary and operating from the ultraviolet to the long wave infrared, is being built as one of the next-generation Extremely Large Telescopes. The size of the GMT and its doubly segmented design create a unique set of challenges for telescope alignment, from initial alignment during the assembly, integration, verification and commissioning phase to operational alignment between and during the telescope exposures. GMT therefore includes a Telescope Metrology System (TMS) that uses networks of laser trackers and absolute and differential distance-measuring interferometers for improved alignment efficiency and phasing of the mirror segments. The TMS has successfully passed its Preliminary Design Review and entered the Final Design phase. In this paper we present the current design and expected performance of the GMT TMS.

A functional and reliable Health Information System (HIS) is vital for data-based decision-making in public health. Here we describe the assessment of data processes and general HIS principles by adapting a global approach to three cities. The assessments supported the data strategy of the CARDIO4cities initiative in each city aiming to improve urban population health by increasing the use of cardiovascular disease (CVD) data to inform decision-making. We aimed to explore data collection processes and entities, data availability and quality as well as data ownership and sharing regarding a set of identified key performance indicators (KPIs). KPIs were based on a global theory of change (ToC) and a global evaluation and indicator framework and were tailored to each location. By first assessing existing sources and processes regarding data, recommendations for changes and improvements are sure to build on current circumstances. To map the data, existing data collection, analysis and storage processes were investigated. A flow chart was created to visualize the data pathways and challenges for each system and findings were compared across cities to document differences and similarities. Data quality and interoperability of various separate systems were the most prominent challenges for all HISs. The observed dvata quality issues originated from incorrect, missing and incomplete data and were connected to the misunderstanding of indicators, incomplete data input forms or the lack of a systematic data routine in the workflow. Harmonization of the HISs to ensure interoperability can facilitate data collection and analysis of health data and can provide a solid basis for health management decision-making. Based on the presented HIS cases, we recommend to examine, map and verify current processes when conducting a HIS assessment, to visualize findings and to gauge the interest of government entities to ensure political support.

The evolutionary paths of social-ecological systems comprise periods of structural continuity punctuated by moments of convulsive change. Various forms of systemic global shock could materialize in the coming decades, triggered by the climate crisis, social disruption, economic breakdown, financial collapse, nuclear conflict, or pandemics. The unfolding COVID-19 pandemic stands as a real-time example of an interruption of historic continuity. More hopefully, deep institutional and cultural shifts could rapidly usher in more resilient forms of global civilization. These plausible possibilities challenge scenario studies to spotlight discontinuous futures, an imperative that has not been adequately met. Several factors—for example, gradualist theories of change, scientific reticence, the lure of quantitative tractability, embeddedness in policymaking processes—have rendered mainstream scenario analysis ill-suited to the task. The emphasis on continuity fails to alert decision makers and the public to the risks and opportunities latent in our singular historical moment. A shift to a paradigm that foregrounds discontinuity is long overdue, calling for efforts to broaden the base of persons involved; devote more attention to balancing narrative storytelling and a broader range of quantitative methods; and apply and develop methods to explicitly consider discontinuities in global scenario development.

Summary Before constructing wind turbines in the south of Groix island, overseas measurements of the total magnetic field were conducted to locate the Unexploded Ordnances (UXO) buried since the Second World War. A set of two magnetometers pulled by a boat was used to measure the magnetic field in go-and-return trajectories. The measurements along north and southward trajectories were correlated. However, the magnetometers systematically recorded a relatively higher magnetic field during the northward course. Using both north and southward measurements resulted in a heterogenous dataset, which created azimuthal artifacts on the produced maps. A Gaussian transformation was used to adapt the statistical distribution of the southward measurements to the northward ones and make the dataset homogeneous. Therefore, the azimuthal artifacts were considerably reduced, and potential UXO locations were detected more easily. Exploratory data analysis and mapping steps were done entirely in the Isatis.neo™ geostatistical software.

BackgroundCardiovascular disease presents an increasing health burden to low- and middle-income countries. Although ample therapeutic options and care improvement frameworks exist to address its prime risk factor, hypertension, blood pressure control rates remain poor. We describe the results of an effectiveness study of a multisector urban population health initiative that targets hypertension in a real-world implementation setting in cities across three continents. The initiative followed the “CARDIO4Cities” approach (quality of Care, early Access, policy Reform, Data and digital technology, Intersectoral collaboration, and local Ownership).MethodThe approach was applied in Ulaanbaatar in Mongolia, Dakar in Senegal, and São Paulo in Brazil. In each city, a portfolio of evidence-based practices was implemented, tailored to local priorities and available data. Outcomes were measured by extracting hypertension diagnosis, treatment and control rates from primary health records. Data from 18,997 patients with hypertension in primary health facilities were analyzed.ResultsOver one to two years of implementation, blood pressure control rates among enrolled patients receiving medication tripled in São Paulo (from 12·3% to 31·2%) and Dakar (from 6·7% to 19·4%) and increased six-fold in Ulaanbaatar (from 3·1% to 19·7%).ConclusionsThis study provides first evidence that a multisectoral population health approach to implement known best-practices, supported by data and digital technologies, and relying on local buy-in and ownership, can improve hypertension control in high-burden urban primary care settings in low-and middle-income countries.

Observing Earth-like exoplanets orbiting within the habitable zone of Sun-like stars and studying their atmospheres in reflected starlight requires contrasts of ∼1e–10 in the visible. At such high contrast, starlight reflected by exozodiacal dust is expected to be a significant source of contamination. Here, we present high-fidelity simulations of coronagraphic observations of a synthetic solar system located at a distance of 10 pc and observed with a 12 m and an 8 m circumscribed aperture diameter space telescope operating at 500 nm wavelength. We explore different techniques to subtract the exozodi and stellar speckles from the simulated images in the face-on, the 30 deg inclined, and the 60 deg inclined case and quantify the remaining systematic noise as a function of the exozodiacal dust level of the system. We find that in the face-on case, the exozodi can be subtracted down to the photon noise limit for exozodi levels up to ∼1000 zodi using a simple toy model for the exozodiacal disk, whereas in the 60 deg inclined case this only works up to ∼50 zodi. We also investigate the impact of larger wave front errors and larger system distance, finding that while the former has no significant impact, the latter has a strong (negative) impact. Ultimately, we derive a penalty factor as a function of the exozodi level and system inclination that should be considered in exoplanet yield studies as a realistic estimate for the excess systematic noise from the exozodi.

One of the greatest technical challenges of the doubly-segmented Giant Magellan Telescope is the accurate and stable control of segment piston in the diffraction limited observation mode. To address this challenge, in collaboration with the University of Arizona, Smithsonian Astrophysical Observatory and the Istituto Nazionale di Astrofisica, GMTO is executing a project to optimize and validate segment piston control strategies and algorithms using a pair of testbeds. The testbeds provide disturbances to simulate atmospheric turbulence and differential atmospheric dispersion. In addition to the phasing demonstration, the testbeds offer the opportunity to validate hardware designs for the Acquisition & Guiding Wavefront Sensor (AGWS) and the Natural Guide Star Wavefront Sensor (NGWS) and to mitigate their fabrication and assembly risks. Significant progress is reported in the design of the AGWS and NGWS prototypes as well as preliminary test results from the testbeds.

Thanks to a diverse constellation of Earth observing satellites, humanity is effectively looking everywhere, at everything, all the time. And we've been quietly doing so for a long time. The challenge is that for many years these massive data archives have been stranded from operational, cloud-based, modern data science. That is changing fast. In this session we'll do a rapid primer on satellite imagery as a source of novel data about our Earth and discuss how machine learning is a key force for translating all of this Earth data into real insights. We'll use the global agriculture system as a case in point, highlighting some of potential that a spaceborne perspective brings to this vital sector of the economy. Along the way, we will explore some of the beautiful imagery of our home planet that fuels this new class of insights.

Economic analyses of the long-term costs of mitigating climate change are unknowable, argue these authors. To base climate policy on them is irresponsible. However, the authors support the moral argument that it is necessary to control climate because its likely devastating effect on human civilization is reason enough to pursue climate mitigation policies. This technical paper is a valuable retort to economic oversimplifications prevalent in the climate change literature.