University of Oregon
  • Eugene, Oregon, United States
Recent publications
Hierarchical control is often thought to dissect a complex task space into isolated subspaces in order to eliminate interference. Yet, there is also evidence from serial-order control tasks that our cognitive system can make use of abstract relationships between different parts (chunks) of a sequence. Past evidence in this regard was limited to situations with ordered stimuli (e.g., numbers or positions) that may have aided the detection of relationships and allowed gradual learning and hypothesis testing. Therefore, we used a modified task-span paradigm (with no ordered elements between tasks) in which participants performed memorized sequences of tasks that were encoded in terms of separate chunks of three tasks each. To allow examination of learning effects, each sequence was "cycled" through repeatedly. Importantly, we compared sequences whose chunks were governed by a common, abstract grammar with sequences whose chunks were governed by different grammars. Experiment 1 examined the effect of relationships between shared-element chunks (e.g., ABB-BAA vs. ABB-BAB), Experiment 2 and 3 between different-element chunks (e.g., ABA-CDC vs. ABA-CCD), and Experiment 4 examined second-order relationships (e.g., ABA-ABB--CDC-CDD vs. ABA-ABB--CDC-CCD). Robust evidence in favor of beneficial effects of abstract inter-chunk relationships was obtained across all four experiments. Importantly, these effects were at least as strong in initial cycles of performing a given sequence as during later cycles, suggesting that the cognitive system operates with an "expectation of abstract relationships," rather than benefitting from them through gradual learning. We discuss the implications of these results for models of hierarchical control.
Background Providing students with worked out problem solutions is a beneficial instructional technique in STEM disciplines, and studying examples that have been worked out incorrectly may be especially helpful for reducing misconceptions in students with low prior content knowledge. However, past results are inconclusive and the effects of incorrect worked examples alone or in combination with correct examples remains unclear. Objectives We aim to address whether studying incorrect examples alone or in combination with correct examples can support the reduction of students' fraction misconceptions, operationalized as errors made with high confidence. Methods After incorrectly solving a sampling problem, 130 students in 4th through 11th grade in the U.S. were randomly assigned to a condition in an online problem set focused on fraction equivalence. Students studied either single‐type worked examples (i.e., correct or incorrect; n = 49) or combination‐type worked examples (correct and incorrect; n = 41) or engaged in a problem‐solving control (n = 50). Results Studying a combination of correct and incorrect worked examples was as effective as the problem‐solving control with feedback at improving fraction equivalence knowledge and reducing the rate of high‐confidence errors. Students in both the combination condition and the problem‐solving with feedback condition outperformed those who studied either correct or incorrect worked examples alone. Conclusions Results support the inclusion of a combination of correct and incorrect worked examples when teaching students with low prior content knowledge. Studying a combination of example types within an online tutor helps to reduce misconceptions about fractions, a topic students commonly struggle with. A problem‐solving task with corrective feedback worked equally well.
Parenting stress and child psychopathology are closely linked in parent-child dyads, but how the bidirectional association varies across childhood and adolescence, and shifts depending on maternal affection are not well understood. Guided by the transactional model of development, this longitudinal, prospective study examined the bidirectional relations between parenting stress and child internalizing and externalizing problems and investigated the moderating role of maternal affection from childhood to adolescence. Participants were from the Future of Families and Child Wellbeing Study, a diverse, nationally representative sample of 2,143 caregiving mothers who completed assessments at children ages 5, 9, and 15. Using cross-lagged panel modeling, we found bidirectional effects between parenting stress and child internalizing and externalizing problems. However, additional multigroup analyses showed that bidirectional associations depend on the levels of maternal affection. In the high maternal affection group, parenting stress at age 5 predicted higher internalizing and externalizing problems at age 9, and reverse child-to-parent paths were found from age 9 to age 15. In contrast, only one cross-lagged path was found in the low maternal affection group. Findings suggest that maternal affection can heighten the transactional associations between parenting stress and child psychopathology.
The paper uses the Neo-Kantian distinction between Natural and Human sciences and its methodological implications to navigate W. E. B. Du Bois’s and Alain L. Locke’s theories of race. In tracing a continuity between these two figures, the paper also shows how their respective reliance on Neo-Kantian categories leads them to different results. The goal is to show how, while Du Bois’s Neo-Kantianism is best understood as a Diltheyan Neo-Kantianism of the psycho-physical unity of human nature influenced by an anti-metaphysical orientation, Locke’s Neo-Kantianism can be seen as a Neo-Kantianism whose focus is the rejection of causality and of the causal nexus between biological and non-biological traits.
We investigate when a Legendrian knot in the standard contact ${{\mathbb{R}}}^3$ has a non-orientable exact Lagrangian filling. We prove analogs of several results in the orientable setting, develop new combinatorial obstructions to fillability, and determine when several families of knots have such fillings. In particular, we completely determine when an alternating knot (and more generally a plus-adequate knot) is decomposably non-orientably fillable and classify the fillability of most torus and 3-strand pretzel knots. We also describe rigidity phenomena of decomposable non-orientable fillings, including finiteness of the possible normal Euler numbers of fillings and the minimisation of crosscap numbers of fillings, obtaining results which contrast in interesting ways with the smooth setting.
The Pilbara craton of northwestern Australia is known for what were, when reported, the oldest known microfossils and paleosols on Earth. Both interpretations are mired in controversy, and neither remain the oldest known. Both the microfossils and the paleosols have been considered hydrothermal artefacts: carbon films of vents and a large hydrothermal cupola, respectively. This study resampled and analyzed putative paleosols within and below the Strelley Pool Formation (3.3 Ga), at four classic locations: Strelley Pool, Steer Ridge, Trendall Ridge, and Streckfuss, and also at newly discovered outcrops near Marble Bar. The same sequence of sedimentary facies and paleosols was newly recognized unconformably above the locality for microfossils in chert of the Apex Basalt (3.5 Ga) near Marble Bar. The fossiliferous Apex chert was not a hydrothermal vein but a thick (15 m) sedimentary interbed within a sequence of pillow basalts, which form an angular unconformity capped by the same pre-Strelley paleosol and Strelley Pool Formation facies found elsewhere in the Pilbara region. Baritic alluvial paleosols within the Strelley Pool Formation include common microfossil spindles (cf. Eopoikilofusa ) distinct from marine microfossil communities with septate filaments ( Primaevifilum ) of cherts in the Apex and Mt Ada Basalts. Phosphorus and iron depletion in paleosols within and below the Strelley Pool Formation are evidence of soil communities of stable landscapes living under an atmosphere of high CO 2 (2473 ± 134 ppmv or 8.8 ± 0.5 times preindustrial atmospheric level of 280 ppm) and low O 2 (2181 ± 3018 ppmv or 0.01 ± 0.014 times modern).
This article illustrates the multi-generational influence of Baldwin’s The Evidence of Things Not Seen on my path as a Black scholar and draws connections between representation, identity, kinship, and the interdependence of Black writers in the fight for social justice. Through tracing Baldwin’s working relationship with my father, former editor of Playboy magazine Walter Lowe Jr., I hope to illuminate the relational underpinnings of Baldwin’s work on the Atlanta child murders, thereby foregrounding the complexities of Black life. This article recognizes Baldwin’s work in Evidence as more than just a new-wave logistical, strategic, textual model of resistance but also as a mode of artistic production arising from a tradition that is deeply felt, collaborative, improvisational, and ancestrally rooted.
This study sought to understand how state-level policies inform and promote the implementation of restorative justice in education (RJE). A content analysis of 60 laws revealed that definitions, structures, and supports varied greatly, causing us to question whether policies support a systematic implementation of RJE and how policies can prevent the misuse of RJE as an alternative system of punishment. We recommend that laws clearly define the paradigm shift underlying RJE, and provide sustained support to promote a realignment of policies and practices with attention to incorporating measures of accountability to larger values surrounding equity and justice.
The use of language is frequently cited as a metric for moral consideration. This metric is typically a tool to exclude animal being from the realm of ethics or to promote human exceptionalism. Maurice Merleau-Ponty claims language is a gesture with varying degrees of complexity. Many animal beings use gesture to convey meaning complex and abstract enough to qualify as language according to Merleau-Ponty’s parameters. Rats, despite being thought of as vermin and of a lower order, are some of the beings that convey abstract and complex meaning through gesture. Rats play, work, socialize, communicate meaning, and even laugh. Rats, along with human and many other animal beings use language and should be usured into the realm of moral consideration with any and all language using beings. If not, some other metric for exclusion would have to be adopted.
Recently reported major element, trace element, and volatile compositions of dacites erupted from Hekla Volcano, Iceland are inconsistent with an anatectic origin. In contrast, all of the data are consistent with dacitic melts being derived by modest amounts of crystallization of an anhydrous assemblage from an andesitic melt. Models that apply straightforward Gd, Yb, Th, and U concentrations, instead of ratios, to the problem show that the crystallization hypothesis remains valid, especially when uncertainties are propagated.
Tertiary chirality describes the handedness of supramolecular assemblies and relies not only on the primary and secondary structures of the building blocks, but also on topological driving forces that have been sparsely characterized. Helical biopolymers, especially DNA, have been extensively investigated as they possess intrinsic chirality that determines the optical, mechanical, and physical properties of the ensuing material. Here we employ the DNA tensegrity triangle as a model system to locate the tipping points in chirality inversion at the tertiary level by X-ray diffraction. We engineer tensegrity triangle crystals with incremental rotational steps between immobile junctions from 3 to 28 base pairs (bp). We construct a mathematical model that accurately predicts and explains the molecular configurations in both this work and previous studies. Our design framework is extendable to other supramolecular assemblies of helical biopolymers and can be used in the design of chiral nanomaterials, optically-active molecules, and mesoporous frameworks.
A key process in central sensory circuit development involves activity-dependent pruning of exuberant terminals. Here, we studied gustatory terminal field maturation in the postnatal mouse nucleus of the solitary tract (NST) during normal development and in mice where their mothers were fed a low NaCl diet for a limited period soon after conception. Pruning of terminal fields of gustatory nerves in controls involved the complement system and is likely driven by NaCl-elicited taste activity. In contrast, offspring of mothers with an early dietary manipulation failed to prune gustatory terminal fields even though peripheral taste activity developed normally. The ability to prune in these mice was rescued by activating myeloid cells postnatally, and conversely, pruning was arrested in controls with the loss of myeloid cell function. The altered pruning and myeloid cell function appear to be programmed before the peripheral gustatory system is assembled and corresponds to the embryonic period when microglia progenitors derived from the yolk sac migrate to and colonize the brain.
Adolescent girls report low physical activity levels and poor body image and self-esteem. This study evaluated the impact of a girls’ health intervention on body image, self-esteem, and physical activity enjoyment. The intervention was grounded in self-determination theory, resulting in lessons designed to promote autonomy, competence, and relatedness. The two primary components of the intervention included opportunities for girls to learn about resistance training as well as ways to improve their psychosocial health (i.e., body image, self-esteem, and physical activity enjoyment). Girls (n = 590), in the intervention (Mage = 12.79, SD = 0.69) and control group (Mage = 12.92, SD = 0.73), completed pre and post measures. A repeated measures MANOVA was conducted to assess changes in body image, self-esteem, and physical activity enjoyment. The intervention resulted in a significant increase in body esteem-appearance, F = 9.23, p = 0.003, and body esteem-weight, F = 4.77, p = 0.029, and a greater, non-significant, increase in self-esteem (3.22%), and physical activity enjoyment (4.01%) compared to the control group. This highlighted the use of the intervention for significant improvements in appearance and weight-related body image. The results support implementing psychosocial lessons, as well as physical activity, in health programming for girls.
The sporadic occurrence of unusually enhanced mental clarity before death has been documented over time and cultures, and reported in patients with and without neurodegenerative diseases, psychiatric disorders, and other neurocognitive deficits, as well as those with nonterminal and terminal conditions. Using a purposive sampling method via existing professional networks, clinical presentations of terminal lucidity in pediatric populations, as witnessed by pediatric oncologists and medical personnel, were solicited. We document clinical presentations suggestive of terminal lucidity in children, which were compiled by their attending physician at two large tertiary pediatric hospitals. Unanticipated and unexplained changes in mental clarity, verbal communication, and/or physical capability in the days and hours before the death of the pediatric patients were observed. Each patient's medical condition should not have allowed for such changes. The phenomenon known as terminal lucidity provides a conceptual framework for these deviations, although more systematic documentation and clinical research is required before definitive conclusions can be drawn.
Collective behavioural plasticity allows ant colonies to adjust to changing conditions. The red harvester ant (Pogonomyrmex barbatus), a desert seed-eating species, regulates foraging activity in response to water stress. Foraging ants lose water to evaporation. Reducing foraging activity in dry conditions sacrifices food intake but conserves water. Within a year, some colonies tend to reduce foraging on dry days while others do not. We examined whether these differences among colonies in collective behavioural plasticity persist from year to year. Colonies live 20–30 years with a single queen who produces successive cohorts of workers which live only a year. The humidity level at which all colonies tend to reduce foraging varies from year to year. Longitudinal observations of 95 colonies over 5 years between 2016 and 2021 showed that differences among colonies, in how they regulate foraging activity in response to day-to-day changes in humidity, persist across years. Approximately 40% of colonies consistently reduced foraging activity, year after year, on days with low daily maximum relative humidity; approximately 20% of colonies never did, foraging as much or more on dry days as on humid days. This variation among colonies may allow evolutionary rescue from drought due to climate change.
Transition metal-catalyzed alkene isomerization is an enabling technology used to install an alkene distal to its original site. Due to their well-defined structure, homogeneous catalysts can be fine-tuned to optimize reactivity, stereoselectivity, and positional selectivity, but they often suffer from instability and non-recyclability. Heterogeneous catalysts are generally highly robust, but they continue to lack active-site specificity and are challenging to rationally improve through structural modification, therefore exhibiting lower catalytic performance. Known single-site heterogeneous catalysts for alkene isomerization utilize precious metals and bespoke, expensive, and synthetically intense supports. Additionally, they generally have mediocre reactivity, inspiring us to develop a heterogeneous catalyst with an active site made from readily available compounds made of Earth-abundant elements. Previous work demonstrated that a very active homoge-neous catalyst is formed upon protonation of Ni[P(OEt)3]4 by H2SO4, generating a [Ni–H]+ active site. This catalyst is in-credibly active, but also decomposes readily, which severely limits its utility. Herein we show that by using a solid acid (sulfated zirconia, SZO300), not only is this decomposition prevented, but high activity is maintained, improved selectivity is achieved, and a broader scope of functional groups is tolerated. Preliminary mechanistic experiments suggest that the catalyst likely goes through an intermolecular, two-electron pathway. A detailed kinetic study comparing the state-of-the-art Ni and Pd isomerization catalysts reveals that the highest activity and selectivity is seen with the Ni/SZO300 system. The reactivity of Ni/SZO300, is not limited to alkene isomerization; it is also a competent catalyst for hydroalkenylation, hydroboration, and hydrosilylation, demonstrating the broad application of this heterogeneous catalyst.
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7,051 members
Cassandra Moseley
  • Institute for a Sustainable Environment
Melynda Casement
  • Department of Psychology
Debra Merskin
  • School of Journalism and Communication
97403, Eugene, Oregon, United States