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Students learn many concepts in the introductory statistics course, but even our most successful students end up with rigid, ritualized knowledge that does not transfer easily to new situations. In this article we describe our attempt to apply theories and findings from learning science to the design of a statistics course that aims to help students build a coherent and interconnected representation of the domain. The resulting "practicing connections" approach provides students with repeated opportunities to practice connections between core concepts (especially the concepts of statistical model, distribution, and randomness), key representations (R programming language and computational techniques such as simulation and bootstrapping), and real-world situations statisticians face as they explore variation, model variation, and evaluate and compare statistical models. We provide a guided tour through our curriculum implemented in an interactive online textbook (CourseKata.org) and then provide some evidence that students who complete the course are able to transfer what they have learned to the learning of new statistical techniques.

High rates of anxiety and depression are reported among youth with autism spectrum disorders. These conditions are generally assessed using measures validated for typically developing youth. Few studies have investigated their validity for autism spectrum disorders, which is crucial for accurate assessment and the provision of proper treatment. The Revised Children's Anxiety and Depression Scale was evaluated with 67 youth with autism spectrum disorders to examine its utility in measuring anxiety and depression in this population. Parents and children (aged 11-15 years) referred to a multisite intervention study completed the Pediatric Anxiety Rating Scale, Multidimensional Anxiety Scale for Children, Anxiety Disorders Interview Schedule, Child Behavior Checklist, and Revised Children's Anxiety and Depression Scale. Results suggest acceptable internal consistency of the Revised Children's Anxiety and Depression Scale. Modest convergent validity was found among the Revised Children's Anxiety and Depression Scale and other standardized measures of anxiety and depression. There were stronger correlations between Revised Children's Anxiety and Depression Scale Total scores and subscales of measures expected to correlate significantly than those not expected to correlate. One exception was a significant association between the Revised Children's Anxiety and Depression Scale and Child Behavior Checklist Attention subscale, calling into question the divergent validity in separating anxiety from attention problems. Overall, results suggest preliminary support for the Revised Children's Anxiety and Depression Scale in youth with high-functioning autism spectrum disorders.

Well‐dated lacustrine records are essential to establish the timing and drivers of regional hydroclimate change. Searles Basin, California, records the depositional history of a fluctuating saline‐alkaline lake in the terminal basin of the Owens River system draining the eastern Sierra Nevada. Here, we establish a U‐Th chronology for the ∼76‐m‐long SLAPP‐SLRS17 core collected in 2017 based on dating of evaporite minerals. Ninety‐eight dated samples comprising nine different minerals were evaluated based on stratigraphic, mineralogic, textural, chemical, and reproducibility criteria. After the application of these criteria, a total of 37 dated samples remained as constraints for the age model. A lack of dateable minerals between 145 and 110 ka left the age model unconstrained over the penultimate glacial termination (Termination II). We thus established a tie point between plant wax δD values in the core and a nearby speleothem δ18O record at the beginning of the Last Interglacial. We construct a Bayesian age model allowing stratigraphy to inform sedimentation rate inflections. We find that the >210 ka SLAPP‐SRLS17 record contains five major units that correspond with prior work. The new dating is broadly consistent with previous efforts but provides more precise age estimates and enables a detailed evaluation of evaporite depositional history. We also offer a substantial revision of the age of the Bottom Mud‐Mixed Layer contact, shifting it from ∼130 ka to 178 ± 3 ka. The new U‐Th chronology documents the timing of mud and salt layers and lays the foundation for climate reconstructions. Plain Language Summary: Searles Lake, California, is currently a dry saltpan; however, in the past, it was a large and deep lake (>200 m). Lake levels have varied with changes in climate. These changes influenced the sediments deposited. Thus, changes in the lake sediments can be applied to understand the past environments of the region. Here, we developed a chronology for a 76‐m‐long sediment core using isotopic dating methods. The lake sediments contain many different minerals which can be dated. However, some of these minerals formed after the lake sediments were deposited and others have been chemically altered in the time since their formation. We developed criteria for the selection of samples that are the most likely to reflect the age of sediment deposition. We used the selected ages along with statistical modeling to determine the ages of the sediments with depth. We find that the core contains a record that spans over 200,000 years, including the last two glacial cycles. The age model presented here lays the foundation for the exploration of how past climate changes impacted water availability and vegetation in southeastern California. Key Points: >200 ka‐long sediment record of southwestern North American paleoenvironmentEstablishes general criteria for selection of evaporite minerals for U‐Th datingExplores a wide range of parameters for Bayesian age‐depth modeling [ABSTRACT FROM AUTHOR]

For most angiosperms, flowers are critical to reproduction because they increase rates of outcrossing. Flowers are highly variable in numerous traits, including size, shape, and color. Most of this variation is thought to have arisen because of selection by pollinators. Yet nonpollinator selection is increasingly being recognized as contributing to floral trait evolution. Nonpollinator agents of selection that often oppose pollinator selection include the physiological and resource costs of producing and maintaining flowers. Here, I (1) summarize recent studies on the macroevolution of floral physiological traits and (2) apply an energy balance model to examine how two pollination traits (flower color and flower size) can interact with hydraulic traits to influence flower physiology. These modeling results show that under certain conditions flower color variation can overwhelm the effects of floral transpiration and flower size variation on flower temperature. Using a novel data set of flower size from the California flora, I show that the range of flower size most common in the California flora is the range in which complex, nonlinear dynamics in flower energy balance occur. These results suggest that floral traits under selection by biotic agents can have large implications for flower physiology, and only some of these potentially deleterious effects can be offset by flower hydraulic traits. These complex interactions between pollination traits (flower size and color) and physiological traits (surface conductance to water vapor) suggest that a more unified framework for understanding the evolution of floral form and function would simultaneously consider the interaction between physiological traits and traits under biotic selection. [ABSTRACT FROM AUTHOR]

High rates of anxiety and depression are reported among youth with autism spectrum disorders. These conditions are generally assessed using measures validated for typically developing youth. Few studies have investigated their validity for autism spectrum disorders, which is crucial for accurate assessment and the provision of proper treatment. The Revised Children’s Anxiety and Depression Scale was evaluated with 67 youth with autism spectrum disorders to examine its utility in measuring anxiety and depression in this population. Parents and children (aged 11–15 years) referred to a multisite intervention study completed the Pediatric Anxiety Rating Scale, Multidimensional Anxiety Scale for Children, Anxiety Disorders Interview Schedule, Child Behavior Checklist, and Revised Children’s Anxiety and Depression Scale. Results suggest acceptable internal consistency of the Revised Children’s Anxiety and Depression Scale. Modest convergent validity was found among the Revised Children’s Anxiety and Depression Scale and other standardized measures of anxiety and depression. There were stronger correlations between Revised Children’s Anxiety and Depression Scale Total scores and subscales of measures expected to correlate significantly than those not expected to correlate. One exception was a significant association between the Revised Children’s Anxiety and Depression Scale and Child Behavior Checklist Attention subscale, calling into question the divergent validity in separating anxiety from attention problems. Overall, results suggest preliminary support for the Revised Children’s Anxiety and Depression Scale in youth with high-functioning autism spectrum disorders. [ABSTRACT FROM PUBLISHER]