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1. Multi-tracer intensity mapping: cross-correlations, line noise & decorrelation

   https://doi.org/10.1088/1475-7516/2021/05/068  

   Schaan, Emmanuel; White, Martin (May 2021, Journal of Cosmology and Astroparticle Physics)

   Abstract Line intensity mapping (LIM) is a rapidly emerging technique for constraining cosmology and galaxy formation using multi-frequency, low angular resolution maps.Many LIM applications crucially rely on cross-correlations of two line intensity maps, or of intensity maps with galaxy surveys or galaxy/CMB lensing.We present a consistent halo model to predict all these cross-correlations and enable joint analyses, in 3D redshift-space and for 2D projected maps.We extend the conditional luminosity function formalism to the multi-line case, to consistently account for correlated scatter between multiple galaxy line luminosities.This allows us to model the scale-dependent decorrelation between two line intensity maps,a key input for foreground rejection and for approaches that estimate auto-spectra from cross-spectra.This also enables LIM cross-correlations to reveal astrophysical properties of the interstellar medium inacessible with LIM auto-spectra.We expose the different sources of luminosity scatter or “line noise” in LIM, and clarify their effects on the 1-halo and galaxy shot noise terms.In particular, we show that the effective number density of halos can in some cases exceed that of galaxies, counterintuitively.Using observational and simulation input, we implement this halo model for the Hα, [Oiii], Lyman-α, CO and [Cii] lines.We encourage observers and simulators to measure galaxy luminosity correlation coefficients for pairs of lines whenever possible.Our code is publicly available at https://github.com/EmmanuelSchaan/HaloGen/tree/LIM .In a companion paper, we use this halo model formalism and codeto highlight the degeneracies between cosmology and astrophysics in LIM, and to compare the LIM observables to galaxy detection for a number of surveys. 

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2. 3MileBeach: A Tracer with Teeth

   https://doi.org/10.1145/3472883.3486986  

   Zhang, Jun; Ferydouni, Robert; Montana, Aldrin; Bittman, Daniel; Alvaro, Peter (November 2021, Proceedings of the ACM Symposium on Cloud Computing)

   We present 3MileBeach, a tracing and fault injection platform designed for microservice-based architectures. 3Mile-Beach interposes on the message serialization libraries that are ubiquitous in this environment, avoiding the application code instrumentation that tracing and fault injection infrastructures typically require. 3MileBeach provides message-level distributed tracing at less than 50% of the overhead of the state-of-the-art tracing frameworks, and fault injection that allows higher precision experiments than existing solutions. We measure the overhead of 3MileBeach as a tracer and its efficacy as a fault injector. We qualitatively measure its promise as a platform for tuning and debugging by sharing concrete use cases in the context of bottleneck identification, performance tuning, and bug finding. Finally, we use 3MileBeach to perform a novel type of fault injection - Temporal Fault Injection (TFI), which more precisely controls individual inter-service message flow with temporal prerequisites, and makes it possible to catch an entirely new class of fault tolerance bugs. 

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3. Reviews and syntheses: Carbonyl sulfide as a multi-scale tracer for carbon and water cycles

   https://doi.org/10.5194/bg-15-3625-2018  

   Whelan, Mary E.; Lennartz, Sinikka T.; Gimeno, Teresa E.; Wehr, Richard; Wohlfahrt, Georg; Wang, Yuting; Kooijmans, Linda M.; Hilton, Timothy W.; Belviso, Sauveur; Peylin, Philippe; et al (January 2018, Biogeosciences)

   Abstract. For the past decade, observations of carbonyl sulfide (OCS or COS) have been investigated as a proxy for carbon uptake by plants. OCS is destroyed by enzymes that interact with CO₂ during photosynthesis, namely carbonic anhydrase (CA) and RuBisCO, where CA is the more important one. The majority of sources of OCS to the atmosphere are geographically separated from this large plant sink, whereas the sources and sinks of CO₂ are co-located in ecosystems. The drawdown of OCS can therefore be related to the uptake of CO₂ without the added complication of co-located emissions comparable in magnitude. Here we review the state of our understanding of the global OCS cycle and its applications to ecosystem carbon cycle science. OCS uptake is correlated well to plant carbon uptake, especially at the regional scale. OCS can be used in conjunction with other independent measures of ecosystem function, like solar-induced fluorescence and carbon and water isotope studies. More work needs to be done to generate global coverage for OCS observations and to link this powerful atmospheric tracer to systems where fundamental questions concerning the carbon and water cycle remain. 

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4. Residence-time-based classification of surface water systems: FRESHWATER RESIDENCE TIME CLASSIFICATION

   https://doi.org/10.1002/2016WR019928  

   Jones, Allan E.; Hodges, Ben R.; McClelland, James W.; Hardison, Amber K.; Moffett, Kevan B. (July 2017, Water Resources Research)
5. Rapid tree water transport and residence times in a Pennsylvania catchment: Rapid Tree Water Transport and Residence Times

   https://doi.org/10.1002/eco.1747  

   Gaines, Katie P.; Meinzer, Frederick C.; Duffy, Christopher J.; Thomas, Evan M.; Eissenstat, David M. (December 2016, Ecohydrology)