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Streamwise turbulence modulation in non-uniform open-channel clay suspension flows
Get PDFCohesive sediment particles are ubiquitous in environmental flows. The cohesive properties of clay promote the formation of clay flocs and gels and relatively small suspended clay concentrations can enhance or suppress turbulence in a flow. Furthermore, flows are naturally non‐uniform, varying in space and time, yet the dynamics of non‐uniform open‐channel clay suspension flows is poorly understood. For the first time, the adaptation time and length scales of non‐uniform clay suspension flows were quantified using novel experiments with spatially varying but temporally uniform flow. Different levels of turbulence enhancement and attenuation were identified as the flow decelerates or accelerates. Results highlight that decelerating clay suspension flows crucially have a longer adaptation time than accelerating clay suspension flows. This is explained by the longer timescale required for the formation of bonds between cohesive particles in turbulence attenuated flows after deceleration than the rapid breakdown of bonds in turbulent flows after acceleration of clay suspension flows. This hysteresis is more pronounced for higher concentration decelerating flows that pass through a larger variety of clay flow types of turbulence enhancement and attenuation. These different adaptation time scales and associated clay flow type transitions are likely to affect clay flow dynamics in a variety of fluvial and submarine settings
In the heat of the moment: An emotion regulation approach for managing anger after brain injury
Get PDFA new chromosome-assigned Mongolian gerbil genome allows characterization of complete centromeres and a fully heterochromatic chromosome
Get PDFChromosome-scale genome assemblies based on ultralong-read sequencing technologies are able to illuminate previously intractable aspects of genome biology such as fine-scale centromere structure and large-scale variation in genome features such as heterochromatin, GC content, recombination rate, and gene content. We present here a new chromosome-scale genome of the Mongolian gerbil (Meriones unguiculatus), which includes the complete sequence of all centromeres. Gerbils are thus the one of the first vertebrates to have their centromeres completely sequenced. Gerbil centromeres are composed of four different repeats of length 6, 37, 127, or 1,747 bp, which occur in simple alternating arrays and span 1-6 Mb. Gerbil genomes have both an extensive set of GC-rich genes and chromosomes strikingly enriched for constitutive heterochromatin. We sought to determine if there was a link between these two phenomena and found that the two heterochromatic chromosomes of the Mongolian gerbil have distinct underpinnings: Chromosome 5 has a large block of intraarm heterochromatin as the result of a massive expansion of centromeric repeats, while chromosome 13 is comprised of extremely large (>150 kb) repeated sequences. In addition to characterizing centromeres, our results demonstrate the importance of including karyotypic features such as chromosome number and the locations of centromeres in the interpretation of genome sequence data and highlight novel patterns involved in the evolution of chromosomes.</p
Attachment, behavior problems and interventions
Get PDFThis paper puts forward an explanation for the frequent co-occurrence of attachment and behavior problems in children and the implications of this for interventions; presents preliminary evidence that some behaviorally based parenting programs reduce child behavior problems through two separate, but mutually reinforcing, processes—improved attachment relationships and increased parental use of behavior management techniques; and suggests next steps for the field to improve outcomes for those children who, without interventions that addresses both relationship building and behavior management, are at risk of significant long-term difficulties
Every story has two sides: evaluating information processing and ecological dynamics perspectives of focus of attention in skill acquisition.
Get PDFDirecting our focus of attention appropriately during task execution can benefitoutcome performance, cognitive efficiency, and physiological efficiency. Forinstance, individuals may benefit from adopting an external focus of attention (i.e.,by focusing attention on the effects of one’s movements on the environment)over an internal focus of attention (e.g., focusing on one’s body movements).However, accounts concerning the theoretical functioning of such effects haveprimarily relied on hierarchical information processing perspectives; far lessconsideration has been given to potentially alternative explanations based onecological dynamics, instances where an internal focus may be desirable over anexternal focus, and the associated applied implications. Within the present review,we: (a) outline the most recent developments in attentional focus research;(b) evaluate similarities and differences between information processing andecological dynamics explanations of the focus of attention effect; (c) providepractical recommendations; and (d) discuss future research avenues. In doing so,a case is made for an “Ecological Dynamics Account of Attentional Focus” to actas an alternative to information processing-based hypotheses
