Plausible Rates Research Articles

Utilising paired measurements of phosphatidylethanol to monitor early success in alcohol abstinence.

Phosphatidylethanol (PEth) is a specific and persisting marker of ethanol (alcohol) consumption. Early success of medically necessary abstinence can be assessed by monitoring PEth disappearance at a biologically plausible rate. This requires an understanding of PEth elimination, its variability and its determinants. To achieve this, we characterised PEth elimination in drinkers who voluntarily abstained. We aimed to derive a nomogram from the data to assist practitioners in recognising abstinence. Twenty-nine usual drinkers who were prepared to abstain from alcohol consumption for 4 weeks were recruited. Erythrocyte PEth was measured weekly. A population pharmacokinetic model for PEth was developed, describing the time-course of PEth elimination. Estimates were derived for population average, inter-individual variability in PEth half-life and any covariate influences. These estimates informed a nomogram of PEth elimination that incorporated a boundary separating continued abstinence from resumed drinking. The nomogram was tested to identify drinking events among participants. The model estimated a population average elimination rate constant (k) of 0.088 day-1, corresponding to a half-life of 7.9 days with a residual coefficient of variation of 8.5%. Elimination was first order and no covariate influences were identified. The nomogram was internally assessed as predictively accurate for 21 successfully abstinent participants and in detecting alcohol consumption in 2 further participants, using a 99.9% prediction interval. The value of PEth in distinguishing alcohol abstinence from consumption is enhanced by using a nomogram to confirm abstinence within weeks of its medically necessary imposition. Further work will establish the value of this approach in clinical practice.

Strong Prediction: Language Model Surprisal Explains Multiple N400 Effects.

Theoretical accounts of the N400 are divided as to whether the amplitude of the N400 response to a stimulus reflects the extent to which the stimulus was predicted, the extent to which the stimulus is semantically similar to its preceding context, or both. We use state-of-the-art machine learning tools to investigate which of these three accounts is best supported by the evidence. GPT-3, a neural language model trained to compute the conditional probability of any word based on the words that precede it, was used to operationalize contextual predictability. In particular, we used an information-theoretic construct known as surprisal (the negative logarithm of the conditional probability). Contextual semantic similarity was operationalized by using two high-quality co-occurrence-derived vector-based meaning representations for words: GloVe and fastText. The cosine between the vector representation of the sentence frame and final word was used to derive contextual cosine similarity estimates. A series of regression models were constructed, where these variables, along with cloze probability and plausibility ratings, were used to predict single trial N400 amplitudes recorded from healthy adults as they read sentences whose final word varied in its predictability, plausibility, and semantic relationship to the likeliest sentence completion. Statistical model comparison indicated GPT-3 surprisal provided the best account of N400 amplitude and suggested that apparently disparate N400 effects of expectancy, plausibility, and contextual semantic similarity can be reduced to variation in the predictability of words. The results are argued to support predictive coding in the human language network.

Phantom Illusion Based Vibrotactile Rendering of Affective Touch Patterns.

Physically accurate (authentic) reproduction of affective touch patterns on the forearm is limited by actuator technology. However, in most VR applications a direct comparison with actual touch is not possible. Here, the plausibility is only compared to the user's expectation. Focusing on the approach of plausible instead of authentic touch reproduction enables new rendering techniques, like the utilization of the phantom illusion to create the sensation of moving vibrations. Following this idea, a haptic armband array (4x2 vibrational actuators) was built to investigate the possibilities of recreating plausible affective touch patterns with vibration. The novel aspect of this work is the approach of touch reproduction with a parameterized rendering strategy, enabling the integration in VR. A first user study evaluates suitable parameter ranges for vibrational touch rendering. Duration of vibration and signal shape influence plausibility the most. A second user study found high plausibility ratings in a multimodal scenario and confirmed the expressiveness of the system. Rendering device and strategy are suitable for a various stroking patterns and applicable for emerging research on social affective touch reproduction.

Forensic Audio and Voice Analysis: TV Series Reinforce False Popular Beliefs

People’s perception of forensic evidence is greatly influenced by crime TV series. The analysis of the human voice is no exception. However, unlike fingerprints—with which fiction and popular beliefs draw an incorrect parallel—the human voice varies according to many factors, can be altered deliberately, and its potential uniqueness has yet to be proven. Starting with a cursory examination of landmarks in forensic voice analysis that exemplify how the voiceprint fallacy came about and why people think they can recognize people’s voices, we then provide a thorough inspection of over 100 excerpts from TV series. Through this analysis, we seek to characterize the narrative and aesthetic processes that fashion our perception of scientific evidence when it comes to identifying somebody based on voice analysis. These processes converge to exaggerate the reliability of forensic voice analysis. We complement our examination with plausibility ratings of a subset of excerpts. We claim that these biased representations have led to a situation where, even today, one of the main challenges faced by forensic voice specialists is to convince trial jurors, judges, lawyers, and police officers that forensic voice comparison can by no means give the sort of straightforward answers that fingerprints or DNA permit.

Exploring the relation between fundamental frequency and spectral envelope in the perception of musical instrument sounds

Pitch and timbre perception centrally depend on fundamental frequency (F0) and spectral envelopes (SE), respectively. However, timbre perception as a function of F0 is less explored in the literature. An analysis-synthesis approach was used to compare sounds with congruent and incongruent F0 and SE parameters via sound pleasantness, brightness, and plausibility ratings. Analyzing 1900 musical instruments and voice sounds, a two-dimensional synthesis space was derived. The space was sampled in its inner and outer regions, reflecting high and low similarity to existing acoustical instrument sounds. Sounds with congruent and incongruent F0-SE relations were synthesized, defining congruency as the co-occurrence of F0 and SE in the analyzed set of sounds. In Experiment 1, inner regions of the space were rated as more pleasant compared to outer regions. Further, sounds with incongruent F0-SE relation were rated as less pleasant only for F0 discrepancies above two octaves. Finally, the first dimension of the space strongly reflected differences in brightness when F0 was controlled for. In Experiment 2, a spectrally more fine-grained resynthesis approach revealed effects of congruency on pleasantness and plausibility for smaller F0 separations. These results provide evidence for a co-dependence of F0 and SE properties in the perception of harmonic sounds.

High-resolution (1 km) Köppen-Geiger maps for 1901–2099 based on constrained CMIP6 projections

We introduce Version 2 of our widely used 1-km Köppen-Geiger climate classification maps for historical and future climate conditions. The historical maps (encompassing 1901–1930, 1931–1960, 1961–1990, and 1991–2020) are based on high-resolution, observation-based climatologies, while the future maps (encompassing 2041–2070 and 2071–2099) are based on downscaled and bias-corrected climate projections for seven shared socio-economic pathways (SSPs). We evaluated 67 climate models from the Coupled Model Intercomparison Project phase 6 (CMIP6) and kept a subset of 42 with the most plausible CO2-induced warming rates. We estimate that from 1901–1930 to 1991–2020, approximately 5% of the global land surface (excluding Antarctica) transitioned to a different major Köppen-Geiger class. Furthermore, we project that from 1991–2020 to 2071–2099, 5% of the land surface will transition to a different major class under the low-emissions SSP1-2.6 scenario, 8% under the middle-of-the-road SSP2-4.5 scenario, and 13% under the high-emissions SSP5-8.5 scenario. The Köppen-Geiger maps, along with associated confidence estimates, underlying monthly air temperature and precipitation data, and sensitivity metrics for the CMIP6 models, can be accessed at www.gloh2o.org/koppen.

Hasty decision making and belief inflexibility in the more delusion prone? A modified disambiguating-scenarios paradigm assessing cognitive biases implicated in delusions.

Contemporary models of psychosis imply that cognitive biases such as the jumping to conclusions (JTC), the bias against disconfirmatory evidence (BADE), and the liberal acceptance (LA) bias play a role in the pathogenesis of delusions. Most of the studies investigating the role of cognitive biases, however, have been conducted with socially neutral or abstract stimuli and have assessed patients with established psychoses. For the present study, we aimed to concurrently investigate multiple biases (i.e., the JTC, BADE, and LA biases) in a community sample with a new paradigm using more socially engaging stimuli. A large sample of participants (N=874) recruited via Amazon Mechanical Turk was subdivided into two groups based on the frequency of their psychotic-like experiences (PLEs) according to the positive subscale score of the Community Assessment of Psychic Experiences (CAPE) and matched based on major demographics variables, resulting in two equally sized groups called High-PLE (at least 2 SD above the mean) and Low-PLE (maximum 0.5 above the mean; n=46 for each group). Using a modified version of the written-scenarios BADE task, which emphasized social interactions between agents embedded in the scenario, participants rated the plausibility of response options in the face of new information. In line with previous findings, the High-PLE group demonstrated the JTC, BADE, and LA biases. That is, the members of this group made more decisions after the initial piece of information, were less likely to revise their beliefs in light of new information, and provided higher plausibility ratings for implausible response options compared to the Low-PLE group. Results corroborate prior findings suggesting that the JTC, BADE, and LA biases may be contributing factors in delusional ideation and that metacognitive biases extend to social situations.

What is wrong with conspiracy beliefs?

The majority of psychological research highlights the role of lapses in rational thinking as a significant contributing factor to conspiracy beliefs (CBs). However, historical examples demonstrate that not all CBs are inherently incorrect. In this paper, we propose a more nuanced approach, suggesting that instead of universally labelling CBs as false or adopting an agnostic stance towards their veracity, it is beneficial to assess the plausibility of each CB individually along a continuum. To achieve this, we recommend utilizing two key indicators: (1) the prior probability of a specific conspiracy theory being true, considered independently of any supporting or contradicting evidence, and (2) the extent to which proponents of a CB demonstrate actively open-minded thinking. We delve into the rationale behind employing such a nuanced approach to evaluating CB plausibility and present several strategies for calculating and integrating plausibility ratings within conspiracy research. Consistent with our proposed framework, we argue that conspiracy researchers possess both the capability and responsibility to differentiate certain CBs as comparatively more irrational than others, provided that such differentiation is based on principled and probabilistic grounds.

Cross cultural verbal cues to deception: truth and lies in first and second language forensic interview contexts.

The verbal deception literature is largely based upon North American and Western European monolingual English speaker interactions. This paper extends this literature by comparing the verbal behaviors of 88 south Asian bilinguals, conversing in either first (Hindi) or second (English) languages, and 48 British monolinguals conversing in English. All participated in a live event following which they were interviewed having been incentivized to be either deceptive or truthful. Event details, complications, verifiable sources, and plausibility ratings were analyzed as a function of veracity, language and culture. Main effects revealed cross cultural similarities in both first and second language interviews whereby all liar's verbal responses were impoverished and rated as less plausible than truthtellers. However, a series of cross-cultural interactions emerged whereby bi-lingual South Asian truthtellers and liars interviewed in first and second languages exhibited varying patterns of verbal behaviors, differences that have the potential to trigger erroneous assessments in practice. Despite limitations, including concerns centered on the reductionary nature of deception research, our results highlight that while cultural context is important, impoverished, simple verbal accounts should trigger a 'red flag' for further attention irrespective of culture or interview language, since the cognitive load typically associated with formulating a deceptive account apparently emerges in a broadly similar manner.

Exploring Plausibility and Presence in Mixed Reality Experiences.

Mixed Reality (MR) applications along Milgram's Reality-Virtuality (RV) continuum motivated a number of recent theories on potential constructs and factors describing MR experiences. This paper investigates the impact of incongruencies that are processed on different information processing layers (i.e., sensation/perception and cognition layer) to provoke breaks in plausibility. It examines the effects on spatial and overall presence as prominent constructs of Virtual Reality (VR). We developed a simulated maintenance application to test virtual electrical devices. Participants performed test operations on these devices in a counterbalanced, randomized 2x2 between-subject design in either VR as congruent or Augmented Reality (AR) as incongruent on the sensation/perception layer. Cognitive incongruence was induced by the absence of traceable power outages, decoupling perceived cause and effect after activating potentially defective devices. Our results indicate that the effects of the power outages differ significantly in the perceived plausibility and spatial presence ratings between VR and AR. Both ratings decreased for the AR condition (incongruent sensation/perception) compared to VR (congruent sensation/perception) for the congruent cognitive case but increased for the incongruent cognitive case. The results are discussed and put into perspective in the scope of recent theories of MR experiences.

Fish damage due to tubular turbine: Experiments and CFD simulations

Fishes passing through a tubular turbine could eventually be damaged by mechanisms such as impact (s), pressure change (A), pressure gradient (B), and shear stress (C). In the study, the damage of the test fish under different pressure conditions is investigated by pressure tests, and the damage thresholds derived from the tests are combined with CFD simulations to further quantify the fish damage mechanisms caused by the tubular turbine under plausible flow rate and head conditions. Pressure tests show the anatomy of the fish (>94%) remains normal if the induced pressure is between −0.015 and 0.68 MPa. However, the induction of larger negative pressures significantly hampered fish health, with 90% of fish dying at −0.075 MPa 1.5 days after the test and 100% 6 days after the test. Additionally, CFD simulation results show that fish are more vulnerable to blade impact than other mechanisms, with the highest injury probability of 11.02%, and this trend decreases with the increase of turbine head, flow rate and guide vane opening. Negative pressure and pressure gradient are the secondary factors, with the highest probability of 6.45% and 4.61%, respectively. Shear stress is the most insignificant factor, with the highest damage probability of only 0.00699%.

Southern Hemisphere Breeding Stock D humpback whale population estimates from North West Cape, Western Australia

Estimates of the abundance of Breeding Stock D humpback whales (Megaptera novaeangliae) are key to the conservation and management of what is thought to be one of the largest populations of the species. Five years (2000, 2001, 2006, 2007 and 2008) of aerial surveys carried out over an eight-year period at North West Cape (Western Australia) using line transect methodology allowed trends in whale numbers to be investigated, and provided a base for comparison with estimates made approximately 400km south at Shark Bay (Western Australia). A total of 3,127 whale detections were made during 74 surveys of the 7,043km2 study area west of NWC. Pod abundance for each flight was computed using a HorvitzThompson like estimator and converted to an absolute measure of abundance after corrections were made for estimated mean cluster size, unsurveyed time, swimming speed and animal availability. Resulting estimates from the migration model of best fit with the most credible assumptions were 7,276 (CI = 4,993–10,167) for 2000, 12,280 (CI = 6,830–49,434) for 2001, 18,692 (CI = 12,980–24,477) for 2006, 20,044 (CI = 13,815–31,646) for 2007, and 26,100 (CI = 20,152–33,272) for 2008. Based on these data, the trend model with the greatest r2 was exponential with an annual increase rate of 13% (CI = 5.6%–18.1%). While this value is above the species’ estimated maximum plausible growth rate of 11.8%, it is reasonably close to previous reports of between 10–12%. The coefficient of variation, however, was too large for a reliable trend estimate. Perception bias was also not accounted for in these calculations. Based on a crude appraisal which yielded an estimated p(0) of 0.783 (from independent observer effort, CV = 0.973), the 2008 humpback population size may be as large as 33,300. In conclusion, the work here provides evidence of an increasing Breeding Stock D population, but further surveys are necessary to confirm whether the population is indeed increasing at its maximum rate.

Predicted Specified STEAM Student Majors Depending On Many Factors Using Generative Adversarial Networks

The traditional educational systems in certain nations, such as those in the Arab world, use the previous year's scores to forecast academic achievement. Meanwhile, the science, technology, engineering, arts and mathematics (STEAM) educational system also considers the student's talents and interests, in addition to their test results, for each of the years of study used to forecast academic achievement. However, despite the numerous variables that could potentially impact a student's future profession, the STEAM educational system accurately predicts the academic achievement of students in five to seven broad majors. A smart model, data, generative, factors (DGF), has been proposed to assign a specific major for each student based on their academic background, interests, skills, and main influencing factors. The DGF model uses the supervised deep neural network and is trained by the generative adversarial network (GAN) algorithm. The DGF model has the capability to predict a specific major among 17 different majors for every student, with a high learning performance (1.4133), a plausible error rate (0.0046), a rational number of learning epochs (206), and an optimal accuracy of 99.99%.

Photochemical Runaway in Exoplanet Atmospheres: Implications for Biosignatures

About 2.5 billion years ago, microbes learned to harness plentiful solar energy to reduce CO2 with H2O, extracting energy and producing O2 as waste. O2 production from this metabolic process was so vigorous that it saturated its photochemical sinks, permitting it to reach “runaway” conditions and rapidly accumulate in the atmosphere despite its reactivity. Here we argue that O2 may not be unique: diverse gases produced by life may experience a “runaway” effect similar to O2. This runaway occurs because the ability of an atmosphere to photochemically cleanse itself of trace gases is generally finite. If produced at rates exceeding this finite limit, even reactive gases can rapidly accumulate to high concentrations and become potentially detectable. Planets orbiting smaller, cooler stars, such as the M dwarfs that are the prime targets for the James Webb Space Telescope (JWST), are especially favorable for runaway, due to their lower UV emission compared to higher-mass stars. As an illustrative case study, we show that on a habitable exoplanet with an H2–N2 atmosphere and net surface production of NH3 orbiting an M dwarf (the “Cold Haber World” scenario), the reactive biogenic gas NH3 can enter runaway, whereupon an increase in the surface production flux of one order of magnitude can increase NH3 concentrations by three orders of magnitude and render it detectable by JWST in just two transits. Our work on this and other gases suggests that diverse signs of life on exoplanets may be readily detectable at biochemically plausible production rates.

The role of hydrogen in decarbonizing a coupled energy system

This paper examines the decarbonization of three coupled energy sectors: electricity, transport and heating/industry. The sector coupling includes the production of hydrogen from each of electricity via electrolysis, the gasification of coal and the reforming of natural gas; the displacement of gasoline/diesel and natural gas by any of these forms of hydrogen; the generation of electricity by gas turbines and reciprocating engines fuelled by either natural gas or any of these forms of hydrogen; and the electrification of the transport fleet. Plausible sensitivities to technological learning, energy efficiency measures, natural gas prices and subsidies for renewables are examined systematically as the coupled system’s total greenhouse gas emissions are reduced to zero.The observed transition to zero emissions finds significant uses for hydrogen from both electrolysis and fossil fuels with carbon capture and storage (CCS). Plausible rates of technological learning from today to 2050 dramatically reduce the total costs and the land area required for achieving deep abatement mainly due to the projected fall in the costs of wind, solar PV and electrolysis. The combination of hydrogen fuelled reciprocating engines, electrolysis and hydrogen gas storage is also observed to provide lower cost, long term electricity storage than batteries and pumped hydropower. Nonetheless, the marginal costs of reducing emissions beyond approximately 90% abatement relative to today are always more than 100 $/tCO2e and land use can increase dramatically. This suggests that negative emission technologies will likely have a role in achieving net-zero emissions in combination with widespread renewable deployment, technological learning and some continued fossil fuel use with CCS.

Philosophers\u2019 linguistic expertise: a psycholinguistic approach to the expertise objection against experimental philosophy

Philosophers are often credited with particularly well-developed conceptual skills. The ‘expertise objection’ to experimental philosophy builds on this assumption to challenge inferences from findings about laypeople to conclusions about philosophers. We draw on psycholinguistics to develop and assess this objection. We examine whether philosophers are less or differently susceptible than laypersons to cognitive biases that affect how people understand verbal case descriptions and judge the cases described. We examine two possible sources of difference: Philosophers could be better at deploying concepts, and this could make them less susceptible to comprehension biases (‘linguistic expertise objection’). Alternatively, exposure to different patterns of linguistic usage could render philosophers vulnerable to a fundamental comprehension bias, the linguistic salience bias, at different points (‘linguistic usage objection’). Together, these objections mount a novel ‘master argument’ against experimental philosophy. To develop and empirically assess this argument, we employ corpus analysis and distributional semantic analysis and elicit plausibility ratings from academic philosophers and psychology undergraduates. Our findings suggest philosophers are better at deploying concepts than laypeople but are susceptible to the linguistic salience bias to a similar extent and at similar points. We identify methodological consequences for experimental philosophy and for philosophical thought experiments.

Assessing the impact of SARS-CoV-2 prevention measures in Austrian schools using agent-based simulations and cluster tracing data

We aim to identify those measures that effectively control the spread of SARS-CoV-2 in Austrian schools. Using cluster tracing data we calibrate an agent-based epidemiological model and consider situations where the B1.617.2 (delta) virus strain is dominant and parts of the population are vaccinated to quantify the impact of non-pharmaceutical interventions (NPIs) such as room ventilation, reduction of class size, wearing of masks during lessons, vaccinations, and school entry testing by SARS-CoV2-antigen tests. In the data we find that 40% of all clusters involved no more than two cases, and 3% of the clusters only had more than 20 cases. The model shows that combinations of NPIs together with vaccinations are necessary to allow for a controlled opening of schools under sustained community transmission of the SARS-CoV-2 delta variant. For plausible vaccination rates, primary (secondary) schools require a combination of at least two (three) of the above NPIs.

Astrochronology of a middle Eocene lacustrine sequence and sedimentary noise modeling of lake-level changes in Dongying Depression, Bohai Bay Basin

It has been demonstrated that the sedimentary deposits of Eocene succession in Bohai Bay Basin in China responded to astronomically forced climate changes. Several sections have been evaluated for cyclostratigraphy and many astronomical time scales (ATSs) have been constructed in Paleogene Bohai Bay Basin. However, the calibrations of age model and the constructed ATSs failed to reach an agreement and many of them relied on totally different orbital interpretations within the same section/borehole. In this work, we generated a new ATS for the middle Eocene lacustrine strata of middle to lower Member 3 (Es3m-l) and upper Member 4 (Es4u) of Shahejie Formation in Bohai Bay Basin. In this research, high resolution natural gamma-ray (GR) data were used for the cyclostratigraphy analysis of Es3m-l and Es4u Members of Well Fanye-1. We filtered ~11.11 m cycles of t Es3m-l and ~9.26 m cycles of Es4u which were directly correlated to the short eccentricity cycles (~100-kyr) of La2004 solution. The geomagnetic polarity ages of C18r/C19n, C19n/C19r and C19r/C20n in Geological Time Scale 2020 were adopted as age markers for the tuning in this study. This astrochronology provided astronomical time scale (ATS) in the range of 39.268 ± 0.050 Ma to 43.621 ± 0.050 Ma in Es3m-l and Es4u Member. The astrochronology of Well Fanye-1 of the same interval had been studied before. However, the ATS built in this paper used correlation coefficient (COCO) analysis and average spectral misfit (ASM) approach to provide quantitative measurement for fitting the observed sedimentary cycles to astronomical periods and given a range of plausible sedimentation rate. In this research, a sedimentary noise model was applied for the detection of high-resolution lake-level variations controlled by orbital forcing. The lake-level variations generated from the sedimentary noise model were supported by previous sequence stratigraphic interpretations. Variable sedimentation could be affected by lake-level changes which have been demonstrated by the evolutionary correlation coefficient analysis of GR series. In addition, from the ATS and thin section observations, it was concluded that carbonate-clay laminae in lacustrine shale were generated annually. Seasonal carbonate-clay laminated shale formations are controlled by orbital scale variability of monsoon and are always developed in a relatively high eccentricity amplitude under deep water environment conditions. Finally, the lake-level rise at ~40.500 Ma to ~40.050 Ma was demonstrated to be the response to Middle Eocene Climate Optimal (MECO) event in lacustrine records.

The Use of Drop-Structures to Increase the Dissolved Oxygen Level along the Cibarani Channel

The Cikapundung river basin community uses the Cibarani channel as a drainage system and water source for fishing. However, the test result released on 9th November 2020 revealed that the channel’s water quality failed to reach the class II raw water standards due to various domestic waste discharges. This led to the performance of various studies to identify pollution control techniques by limiting the wastewater discharge and quality, controlling the intake discharge, and using baffles. The Cibarani channel has a drop-structure that can improve the water quality, though the effect has not been previously detailed. Therefore, this study was intended to comprehensively examine the effect of the drop-structure along the Cibarani channel to improve water quality conditions, specifically the Dissolved Oxygen (DO) parameter. This study employed the one-dimensional HEC-RAS software to simulate the hydrodynamic and water quality conditions along the Cibarani channel, and the drop-structure was modelled using two alternatives consisting of a vertical wall and a steep riverbed. Subsequently, the drop-structure fitted with a vertical wall gave a more plausible reaeration rate of 125 day-1 and Root Mean Square Error (RMSE) value of 0.50. The placement of a similar configuration before the first housing of the channel increased the DO concentrations by an average of 4.37 mg/L. This was followed by the modelling of another drop-structure after the first housing to increase the DO levels at the downstream part. Eventually, the combination of the two new drop-structures succeeded in increasing the DO concentrations along the Cibarani channel to 3.3 - 6.9 mg/L.

The structure and volume of large geysers in Yellowstone National Park, USA and the mineralogy and chemistry of their silica sinter deposits

Siliceous sinter is formed by biogenic and abiogenic opal deposition around hot springs and geysers. Using Structure-from-Motion photogrammetry we generated three-dimensional models of Giant and Castle Geysers from the Upper Geyser Basin of Yellowstone National Park. We use these models to calculate an approximate mass of sinter for each (~2 and ~ 5 kton, respectively) and estimate a range of plausible long-term deposition rates for Castle Geyser (470 to 940 kg·yr−1). We estimate ~2% of the silica discharged from Castle Geyser is deposited as sinter in the cone and proximal terraces. We collected 15 sinter samples following the stratigraphy of each geyser from the older terrace to the younger cone and examined them using a variety of analytical methods. We find that young opaline sinter with high water content (<12 wt% from loss on ignition) contains higher concentrations of major and trace elements, notably As, Sb, Rb, Ga and Cs, relative to older dehydrated sinter. Rare earth element (REE) concentrations in sinter are 2–3 orders of magnitude higher than in the thermal water from which they are deposited. Sinter deposits are enriched in light REE, Gd and Yb when normalized to concentrations in thermal water and enriched in Eu, Tm, and Yb when normalized to the underlying rhyolite. Sinter samples with the highest REE concentrations are also enriched in organic material, implying either microbial uptake of REE, or that organic molecules are efficient ligands that form metal complexes.