University of Oregon
  • Eugene, Oregon, United States
Recent publications
The accurate simulation of additional interactions at the ATLAS experiment for the analysis of proton–proton collisions delivered by the Large Hadron Collider presents a significant challenge to the computing resources. During the LHC Run 2 (2015–2018), there were up to 70 inelastic interactions per bunch crossing, which need to be accounted for in Monte Carlo (MC) production. In this document, a new method to account for these additional interactions in the simulation chain is described. Instead of sampling the inelastic interactions and adding their energy deposits to a hard-scatter interaction one-by-one, the inelastic interactions are presampled, independent of the hard scatter, and stored as combined events. Consequently, for each hard-scatter interaction, only one such presampled event needs to be added as part of the simulation chain. For the Run 2 simulation chain, with an average of 35 interactions per bunch crossing, this new method provides a substantial reduction in MC production CPU needs of around 20%, while reproducing the properties of the reconstructed quantities relevant for physics analyses with good accuracy.
The ATLAS experiment at the Large Hadron Collider has a broad physics programme ranging from precision measurements to direct searches for new particles and new interactions, requiring ever larger and ever more accurate datasets of simulated Monte Carlo events. Detector simulation with Geant4 is accurate but requires significant CPU resources. Over the past decade, ATLAS has developed and utilized tools that replace the most CPU-intensive component of the simulation—the calorimeter shower simulation—with faster simulation methods. Here, AtlFast3, the next generation of high-accuracy fast simulation in ATLAS, is introduced. AtlFast3 combines parameterized approaches with machine-learning techniques and is deployed to meet current and future computing challenges, and simulation needs of the ATLAS experiment. With highly accurate performance and significantly improved modelling of substructure within jets, AtlFast3 can simulate large numbers of events for a wide range of physics processes.
The gleno-acetabular distance D GA , a conventional proxy for the size of a quadrupedal trackmaker, is often estimated as the distance GA between the midpoint between a left and right pair of pes tracks and the midpoint between a selected pair of left and right manus tracks. While frequently used to estimate trackmaker size from fossil trackways, the relationship between GA and D GA depends upon the gait (which is unknown for extinct trackmakers), and is subject to multiple additional sources of uncertainty including which specific pair of manus tracks to associate with a given pair of pes tracks. Here a generalization is introduced, termed coupling length, which does not require any presumption about trackmaker gait of the degree of overstepping. On the contrary, a systematic analysis of a trackway in terms of coupling length can permit estimation of both the size and the gait with which the trackmaker progressed. Coupling length can be computed at successive points along a trackway, allowing exploration of a range of hypothetical gaits and body sizes for the trackmaker responsible. A fitness function quantifying persistent variation in coupling length along a trackway is used to indicate whether a given trackway could have been created by a fairly consistent gait, and if so, a range of high-fitness solution gaits and their associated D GA . The method was applied to selected quasi-regular sauropod trackways and a solution found for a narrow range of gaits with limb phase of about 0.3 and D GA = 1.6 ± 0.2 m. This is the first estimation of sauropod trackmaker gait, and introduces a novel method by which irregularity along a trackway is used as a source of information to constrain inferences of trackmaker behavior. The computed D GA for this sauropod suggests significantly smaller trackmakers than conventional estimations based on track dimensions and hip height estimates. Size estimation by this approach offers greatly reduced uncertainty compared to conventional estimates.
The brain undergoes profound development across childhood and adolescence, including continuous changes in brain morphology, connectivity, and functioning that are, in part, dependent on one’s experiences. These neurobiological changes are accompanied by significant changes in children’s and adolescents’ cognitive learning. By drawing from studies in the domains of reading, reinforcement learning, and learning difficulties, we present a brief overview of methodological approaches and research designs that bridge brain- and behavioral research on learning. We argue that ultimately these methods and designs may help to unravel questions such as why learning interventions work, what learning computations change across development, and how learning difficulties are distinct between individuals.
Background Over the past several years, cannabis has become legal for recreational use in many US states and jurisdictions around the world. The opening of these markets has led to the establishment of hundreds of cannabis production and retail firms with accompanying demand for labor, leading to concerns about spillover effects on wages from incumbents. Methods We study the markets for agricultural and retail labor in Washington and Colorado from 2000 to 2019 using differences-in-differences with synthetic controls. We employ employment data from the Quarterly Census of Employment and Wages, state-level demographic data from the US Census Bureau, and agricultural data from the National Agricultural Statistics Service. We use the least absolute shrinkage and selection operator (LASSO) for variable selection and classification and regression trees (CART) for chained imputation of missing values. Results We find little-to-no evidence of a significant difference in weekly wages per worker generated by cannabis legalization: the log of the weekly wage per worker decreases by 0.013 in Washington’s agricultural sector ( p value 0.091) and increases by 0.059 in Washington’s retail sector ( p value 0.606). Results in Colorado are qualitatively similar. These results are limited in part by the short post-legalization period of the data. Conclusions Cannabis legalization is unlikely to negatively impact incumbent agriculture or retail firms through the labor market channel.
The recent paper “Reward is Enough” by Silver, Singh, Precup and Sutton posits that the concept of reward maximisation is sufficient to underpin all intelligence, both natural and artificial, and provides a suitable basis for the creation of artificial general intelligence. We contest the underlying assumption of Silver et al. that such reward can be scalar-valued. In this paper we explain why scalar rewards are insufficient to account for some aspects of both biological and computational intelligence, and argue in favour of explicitly multi-objective models of reward maximisation. Furthermore, we contend that even if scalar reward functions can trigger intelligent behaviour in specific cases, this type of reward is insufficient for the development of human-aligned artificial general intelligence due to unacceptable risks of unsafe or unethical behaviour.
For centuries, glass money beads (udoud) have played a critical role in cultural and economic exchanges in the Palauan archipelago (western Micronesia) since their first appearance ca. AD 600-950 from East Java and mainland Southeast Asia. Later, as part of their stone money (rai) quarrying activities, visiting Yapese islanders negotiated access to quarry sites and purchased provisions using glass beads, corvée labor, and other exchange valuables. Here, we present morphological and chemical composition analysis of 38 glass beads recovered from Chelechol ra Orrak, the only quarry site where udoud have been recovered. Analysis reveals that most of the beads were manufactured in Europe, with many originating in Bohemia (present-day Czech Republic) ca. AD 1830-1850. Many of these beads would have been regarded as cheldoech, a category of udoud that largely went out of circulation in the 1920s due to the ease of counterfeiting. Although this category of udoud could be easily counterfeited and beads from Yap lacked the requisite life histories associated with traditional udoud, Palauans accepted them as authentic. However, our research suggests that cheldoech may have depreciated in value well before the 1920s, with Palauans valuing and exchanging this category of udoud in new ways, including interment with burials.
The capital of Angkor remained the powerbase of the Khmer polity for more than 600 years, indicating its resilience. Recent work at Angkor investigates the evolution of this massive agro-urban center, but most of that research has focused on large-scale landscape developments rather than occupational sequences at urban localities. Our paper blends remotely-sensed ground survey, excavation, art historic, and epigraphic data in the Pre Rup area (and specifically around the Kok Phnov settlement) to provide a fine-grained perspective on the development of Angkor's urban configuration through time. We write against the assumption that successive state temples defined neighborhoods and temple communities across Angkor urban space and illustrate their interconnectivity as “districts” that sustained the urban core. Districts, as administrative units, included civic-ceremonial, craft production, and residential neighborhoods. Drawing on field-based investigations of mound clusters at Kok Phnov we offer evidence for continuous habitation and craft production from the 9th–16th centuries. We use this patterning in the larger Eastern District to argue that Angkorian urbanism developed unevenly through time and space, and that bottom-up social forces – as well as state design and topography – crafted its form. Such neighborhoods and districts were foundational elements to Angkorian urbanism, and studying their occupational sequences sheds light on Angkor's dynamic and resilient 600-year urban history.
Extreme heat events are becoming more frequent and more severe in the Pacific Northwest and in comparable dry-summer climates worldwide, increasing the occurrence of heat-related illness and death. Much of this risk is attributed to overheating in multifamily dwellings, particularly in neighborhoods with abundant asphalt, few trees, and limited financial resources. Air-conditioning expansion is problematic, however, because it creates vulnerability to operational costs and power outages, while expelled hot air intensifies urban heat island effects. In contrast, passive cooling strategies that deflect solar radiation and recruit the cool night air typical of Mediterranean, semi-arid, and arid climates are quite promising, but their abilities to improve residential survivability during extreme heat have not yet been explored. To understand this potential, here we investigate the extent to which well-controlled shading and natural ventilation, in some cases with fan assistance, could have diminished the hours in which indoor heat index levels exceeded ‘caution’, ‘extreme caution’, ‘danger’, and ‘extreme danger’ thresholds during the June 2021 heat wave in the Pacific Northwest; building thermal performance was simulated in EnergyPlus under conditions experienced by Vancouver BC, Seattle WA, Spokane WA, Portland OR, and Eugene OR. Strikingly, we find that in Portland, where the highest temperatures occurred, integrated shading and natural ventilation eliminated all hours above the danger threshold during the 3-day event, lowering peak indoor air temperatures by approximately 14 °C (25 °F); without cooling, all 72h exceeded this threshold. During the encompassing 10-day period, these passive measures provided 130–150h of thermal relief; baseline conditions without cooling provided none. Additionally, passive cooling reduced active cooling loads by up to 80%. Together, these results show the immediate, substantial value of requiring effective operable shading and secure operable windows in apartments in mild dry-summer climates with rising heatwave intensity, as well as public health messaging to support the productive operation of these elements.
Forest treatments reduce wildfire risk and can promote the vigor and production of remaining trees, but they are also a disturbance. Understanding the type, timing, and longevity of tree response to treatment, as well as the potential for interactive effects of treatments and drought, could help managers plan and evaluate forest management practices. Environmental drivers, biological modifiers, and tree capacity to respond to prior disturbances were concurrently tested to predict ponderosa pine basal area increment (BAI) in a lowland and upland dry pine forest in south central Oregon, USA. Environmental drivers included current year and lags or running averages of a drought index, SPEI, and the sum or count of growing degree days >0°C or 10°C. Biological modifiers of environmental drivers considered pre-treatment response to disturbance, tree vigor, and tree-to-tree competition. A model was developed to predict BAI in both topographic positions for applicability to the landscape level, and then was used to test for specific differences in BAI between paired forest treatments differing by one treatment. Forest treatments tested included no management (NM), undercut and even spacing harvest (HE), prescribed fire (Rx), and their combinations. HE significantly increased BAI shortly after treatment. Post-harvest, one or two Rx did not provide additional BAI benefits, nor in the absence of HE, did 2Rx vs. 1Rx treatment. The 1Rx treatment was imposed between multi-year droughts; BAI significantly increased after the treatment and was resistant to droughts. Upland trees were affected by a single year of drought; lowland trees responded only after sequential drought years. A single treatment, HE or 1Rx appeared to be as effective as multiple or mixed treatments in improving BAI in dry pine forest stands. HE appeared to generate the largest effect. Timing of forest treatments relative to site water balance may affect short term (decadal) wood production.
We propose a novel model to explain the mechanisms underlying dominance hierarchical structures. Guided by a predetermined social convention, agents with limited cognitive abilities optimize their strategies in a Hawk-Dove game. We find that several commonly observed hierarchical structures in nature such as linear hierarchy and despotism, emerge as the total fitness-maximizing social structures given different levels of cognitive abilities.
We provide the first estimates of the impacts of prenatal exposure to extreme temperatures on infant health at birth using the latest national birth data from 2009 to 2018 from all U.S. states. We consistently find that an additional day with mean temperature greater than 80°F or less than 10°F increases preterm births and low birthweight. Strikingly, the adverse effects are borne disproportionately by Black and Hispanic mothers, suggesting that the projected increase in extreme temperatures may further exacerbate the existing birth health disparities across different race/ethnicity groups. We also contribute by investigating the impact of deviations from the normal weather pattern, to identify the extreme weather events after accounting for the adaptation response. We find that prenatal exposure to extreme heat two standard deviations above county's historic average induces preterm births and NICU admissions, particularly for mothers whose pregnancies overlap with summer months. These results are timely and policy relevant, considering the recent weather trends with rising temperatures and frequent extreme weather events.
Paleosols are useful evidence of paleoclimates and paleoenvironments independent of fossils. Zhangye Danxia National Geopark of Gansu Province (northwestern China) has been protected for its stunning varicolored badlands of Early Cretaceous (Aptian-Albian) claystones. However, the paleoclimates and paleoenvironments forming such unique succession are currently not well understood. The widespread pedogenic features, for example root traces and soil horizons, indicate different paleosols, which provides clues of associated paleoclimates and paleoenvironments. In the present study, combining field work and soil micromorphology, we recognized, classified, and interpreted 155 sequential paleosol profiles of 14 different pedotypes (soil types) in the 755-m-thick section. These pedotypes have modern analogues in South Asia, indicating hotter and more humid paleoclimate than at present in Zhangye. Systematic analysis of soil units based on comparison to their modern analogues allows reconstruction of paleoenvironments in eleven humidity stages. Variation in waterlogging of the paleosols based on the ratio of Hm / Gt agreed well with regional and global paleoclimatic records, confirming its utility in paleoclimate reconstruction during Aptian and Albian. The identification and characterization of the paleosol succession provides a significant base for detailed paleoclimatic reconstruction during this period.
We study generalized Deligne categories and related tensor envelopes for the universal two-dimensional cobordism theories described by rational functions, recently defined by Sazdanovic and one of the authors.
We introduce a notion of mean cohomological independence dimension for actions of discrete amenable groups on compact metrizable spaces, as a variant of mean dimension, and use it to obtain lower bounds for the radius of comparison of the associated crossed product C⁎-algebras. Our general theory, gives the following for the minimal subshifts constructed by Dou in 2017. For any countable amenable group G and any polyhedron Z, Dou's subshift T of ZG with density parameter ρ satisfiesrc(C(X)⋊TG)>12mdim(T)(1−1−ρρ)−2. If k=dim⁡(Z) is even and Hˇk(Z;Q)≠0, thenrc(C(X)⋊TG)>12mdim(T)−1, regardless of what ρ is.
Icelandic basalts have low oxygen isotope (δ18O) values compared to other ocean island localities. While this observation is often ascribed to the assimilation of low-δ18O crust, a low-δ18O mantle beneath Iceland has also been suggested. To discern crustal from mantle-derived signals, high-quality in-situ and bulk crystal δ18O measurements have been obtained from olivine crystals covering 16 Ma of activity at the Iceland hotspot. The results are combined with olivine (ol) major, minor and trace element chemistry. Relationships between δ18Ool and indicators of melt evolution do not support a singular process responsible for lowering of δ18O values. However, correlations are observed between δ18Ool values and indicators of crustal processes. Such patterns are used to filter out data that are likely to reflect effects from crustal assimilation to highlight δ18Ool values indicative of source-derived variability only. Although filtered, the dataset reveals, that δ18Ool values, significantly lower than the canonical depleted upper mantle value, are derived from the Iceland mantle. Coupled δ18Ool and ³He/⁴Heol measurements done on olivine crystals from the same samples demonstrate that low-δ18O components (down to δ18Oolivine = 4.2‰) are a trait of the modern Iceland plume and that low-δ18O and low-³He/⁴He components have become more apparent in the hotspot products since 60 Ma. Olivine chemistry characteristics suggest that this low-δ18O component is best sampled in melts that reflect contributions from pyroxenitic mantle lithologies, likely related to the recycling of oceanic lithosphere within the plume. An increase in plume flux, as traced by increasing plume temperatures and plume buoyancy after 35 Ma, led to enhanced entrainment of lower mantle material carrying recycled low-δ18O oceanic lithosphere. Such material has become more apparent with time as is reflected in source-derived low-δ18O and high ³He/⁴He values in olivine from the modern Iceland plume. Moreover, the coincidence of the Iceland plume-head and the North Atlantic Rift at from ∼25 Ma likely assisted and further promoted enhanced plume-melting. Thus, the combination of changes in mantle upwelling and tectonic reorganisation of the North Atlantic led to the introduction of recycled oceanic lithosphere into the Iceland plume and the formation of the Iceland Plateau ∼25 Ma.
Nitric oxide (NO) is an ancestral key signalling molecule essential for life and has enormous versatility in biological systems, including cardiovascular homeostasis, neurotransmission and immunity. Although our knowledge of NO synthases (Nos), the enzymes that synthesize NO in vivo , is substantial, the origin of a large and diversified repertoire of nos gene orthologues in fishes with respect to tetrapods remains a puzzle. The recent identification of nos3 in the ray-finned fish spotted gar, which was considered lost in this lineage, changed this perspective. This finding prompted us to explore nos gene evolution, surveying vertebrate species representing key evolutionary nodes. This study provides noteworthy findings: first, nos2 experienced several lineage-specific gene duplications and losses. Second, nos3 was found to be lost independently in two different teleost lineages, Elopomorpha and Clupeocephala. Third, the expression of at least one nos paralogue in the gills of developing shark, bichir, sturgeon, and gar, but not in lamprey, suggests that nos expression in this organ may have arisen in the last common ancestor of gnathostomes. These results provide a framework for continuing research on nos genes’ roles, highlighting subfunctionalization and reciprocal loss of function that occurred in different lineages during vertebrate genome duplications.
This paper presents a method that uses observed data from an age-period table to set bounds on the age, period, and cohort effects in an age-period-cohort multiple classification (APCMC) model. The rationale is that with enough periods over a long time span the age distributions within periods on the dependent variable will be affected by different sets of cohorts for each of the periods. This is likely to result in different trends in these separate period age distributions such that the trends in the age distributions will encompass the trend in the age effects that generated the dependent variable values. This approach can help to identify bounds that likely encompass the age, period, cohort parameters that generated the data. The data used in this papers are estimated homicide arrests by single years for those aged 15–64 for the periods 1964 to 2019 in the United States. I utilize the observed trends in the age-distributions for each of the 56 periods as different constraints on the trends for the age effects in the APCMC fixed effects model. These estimates are used to form bounds on the age effects, period effects, and cohort effects.
Parenting skills are important protective factors in the prevention of bullying and cyberbullying, yet few parent-based interventions have been developed and evaluated in this area. This pilot study examined participant responsiveness to and acceptability of an evidence-based parenting curriculum enhanced to address bullying and cyberbullying. Enhancements included intensive role playing, social emotional coaching, and media parenting. The pilot was delivered online via video conferencing during the unique circumstances of the coronavirus disease pandemic 2019 (COVID-19) shelter-at-home orders. Parents (N = 32; 88% female) participated in weekly online sessions; 30 completed all eight sessions. Using a sequential exploratory mixed method approach, we first conducted quantitative analyses to examine participant responsiveness and qualitative analyses to further explain outcomes and explore participant acceptability. Satisfaction with individual sessions was high. In a few sessions, satisfaction and home practice completion was lower among those with free- and reduced-price lunch eligibility. Qualitative data reinforced and explained quantitative findings. Participants were appreciative of the program and delivery, particularly during the shelter-at-home conditions. They voiced satisfaction with the online format and with home practice assignments. They also made suggestions to strengthen the emphasis on bullying and cyberbullying in the program. Results suggest that the program and enhancements to the program were acceptable to participants, and high rates of satisfaction suggest that video conferencing is a feasible delivery format. Further, parental programming during the stressful context of the COVID-19 pandemic was well received. Although few differences in satisfaction by free- and reduced-priced lunch were observed, technology support for low-income families may be warranted.
District leadership teams perform key roles in building the systems to support schools in the implementation of Positive Behavioral Interventions and Supports (PBIS). However, there is a lack of measures for assessment and progress monitoring specific to district PBIS systems. To address this gap, we evaluated the validity of a measure of implementation of district PBIS systems, the District Systems Fidelity Inventory (DSFI). Using 183 school districts and 760 schools implementing PBIS, we found the DSFI to have good evidence of structural validity for measuring nine aspects of district systems (Leadership Teaming, Stakeholder Engagement, Funding and Alignment, Policy, Workforce Capacity, Training, Coaching, Evaluation, and Local Implementation Demonstrations). We also found DSFI subscales to be moderately related to school-level PBIS implementation fidelity, providing evidence of convergent validity. We describe how leadership teams can use the DSFI to improve PBIS implementation and student outcomes.
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6,558 members
Cassandra Moseley
  • Institute for a Sustainable Environment
Melynda Casement
  • Department of Psychology
Debra Merskin
  • School of Journalism and Communication
Amy Elizabeth Mahady
  • Institute of Molecular Biology
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