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San Fernando Valley spineflower (Chorizanthe parryi var. fernandina [S. Watson] Jeps.) (Polygonaceae) is an herbaceous annual plant, endemic to California, and until rediscovered in 1999 had been thought to be extinct for almost seven decades. Historically documented at 10 locations, it currently persists at 2, separated by approximately 27 km. State listed as endangered, a description of its genetic diversity and structure is of conservation interest. After determining a lack of variation in ploidy, we examined genetic variation from samples within both populations: a common garden study for potentially adaptive genetic variation in selected growth and phenological traits and analysis of single nucleotide polymorphisms identified through restriction-site associated DNA sequencing. Both measures indicated that this highly restricted taxon nevertheless harbors substantial levels of genetic diversity and has significant between- and within-population genetic structure. Combining approaches from population genomics and common garden studies provided more insight into the patterns and basis of genetic diversity than is typical for studies of non-model species. Although local adaptation was not specifically studied (i.e., via reciprocal transplant studies), the differences determined from these two independent lines of evidence indicate that mixing gene pools between populations is not recommended at this time. Further, with significant differences revealed among subpopulations, we caution against mixing genotypes across subpopulations for the most part, and without much more evidence that this would not pose a risk of outbreeding depression. The importance of supporting pollinator health and diversity is highlighted. With genetic diversity—particularly with an annual species—being dynamic, fluctuating with the usual processes and with contributions from the soil seedbank, we recommend periodic resampling to monitor genetic diversity and structure. Climate change is anticipated to contribute to this variability.

Accurate taxonomic identification is foundational for effective species monitoring and management. When visual identifications are infeasible or inaccurate, genetic approaches provide a reliable alternative. However, these approaches are sometimes less viable (e.g., need for near real-time results, remote locations, funding concerns, molecular inexperience). In these situations, CRISPR-based genetic tools can fill an unoccupied niche between real-time, inexpensive, but error-prone visual identification and more expensive or time-consuming, but accurate genetic identification for taxonomic units that are difficult or impossible to visually identify. Herein, we use genomic data to develop CRISPR-based SHERLOCK assays capable of rapidly (

Objective: Speckled Dace Rhinichthys osculus is small cyprinoid fish that is widespread in western North America. In California and elsewhere it is currently treated as a single species with multiple subspecies, many undescribed. However, these subspecies may represent evolutionary lineages that are cryptic species because they cannot be distinguished using standard morphometric techniques. In this study, we attempt to determine evolutionary lineages within California populations of Speckled Dace using the population genetic and genomic information. Methods: We used restriction site-associated DNA sequencing to extract thousands of single-nucleotide polymorphisms across the genome to identify genetic differences among all the samples from 38 locations in the western USA, with a focus on California. We performed principal component analysis, admixture analysis, estimated pairwise values of the genetic differentiation index FST, and constructed molecular phylogenies to characterize population genetic and phylogenetic relationships among sampled Speckled Dace populations. Result: Our analyses detected three major lineages of Speckled Dace in California that align with geography: (1) Sacramento River, central California coast, Klamath River, and Warner Basin; (2) Death Valley and Lahontan Basin; and (3) Santa Ana River basin, in southern California. These lineages fit well with the geologic history of California, which has promoted long isolation of populations of Speckled Dace and other fishes. Conclusion: The presence of distinct evolutionary lineages indicates that Speckled Dace in California should be managed with distinct population segments to preserve within-species diversity. This study highlights the importance of genetic analyses for conservation and management of freshwater fishes.

Purpose: Schools across the predominately rural state of West Virginia are experiencing widespread teacher shortages, though recruitment and retention difficulties are unevenly distributed across place. Using spatial in/justice as our framework, we explore how principals define place, how place influences principal perceptions of teacher recruitment and retention, and how principals respond to these staffing challenges given their leadership experiences, relationship to school community, and understandings of place affordances and disadvantages. Research Methods/Approach: This research utilized interviews with eight principals across six school districts in West Virginia over a four-month time frame. We inductively coded interview transcripts in iterative cycles using our research framework as a guide for emic and etic codes. Findings: We find principals' understanding of place influences on staffing to be specific to the unique attributes of each community and the placement of their leadership experiences -- as community returners, seasoned though not originally from the community, and new-to-place. Their understandings of spatial in/justice as it relates to teacher staffing shape ideas of place affordances and disadvantages and recruitment and retention practices. These findings complexify the teacher staffing picture across geographically diverse rural places and the responses available to leaders given their leadership experience and relationship to place. Implications for Research and Practice: The place-specific influences on teacher staffing problematize statewide policy mechanisms for ameliorating teacher shortages. The findings also suggest the need for further in-depth qualitative research within districts and across states, with an emphasis on racially diverse rural places.

Responding to student errors is a complex practice that connects teachers' vision and goals around students, mathematics, and teaching. We explore teacher candidates' (TCs) reflections on responding to errors during rehearsals of whole-class discussion to gain insight into the vision and goals that might influence their thinking. We discuss five TCs' assessment of their practice based on video-elicitation interviews to infer their vision around responding to errors and their associated goals for practice. In particular, we attend to how their vision and goals interact in shaping TCs' reflections on practice. This work offers implications for considering TC development and support.

There is a growing interest in understanding and evidencing quality WIL practice across higher education institutions. Despite this increasing focus there is limited evidence of shared institutional wide approaches to defining attributes of quality, establishing benchmarks of WIL in practice (i.e. the enacted WIL curriculum), and implementing a shared evidence-based approach to assuring quality in WIL. This paper presents the underpinning rationale for a quality assurance framework for WIL practice developed through a research project which engaged participants from across the Australian higher education context. The project had three phases: review, exploration and benchmarking; to develop a comprehensive framework representing the dynamic and complex practice space of WIL within higher education institutions. This paper highlights key outcomes from each phase and how these have informed the content and usability of the proposed quality assurance framework, thus providing a robust, evidence-based and comprehensive instrument for the quality assurance of WIL across an institution.

Approximations of practice in teacher education provide learning opportunities for teacher candidates (TCs) in a space that is less authentic than classroom teaching, yet still maintains the complexity and interactive nature of core teaching practices. There exists a need for more research focused on documenting TCs' learning through such pedagogies. In this paper, we highlight two cases of secondary mathematics TC learning around the practice of responding to errors in whole-class discussion. We consider multiple components of resources TCs brought to the work of teaching that were supported by and made visible through two types of approximations--coached rehearsals and scripting tasks--at multiple moments in time over a semester-long methods course. This work contributes to the research on practice-based pedagogies in teacher education by offering detailed images that illustrate the nature of two TCs' learning over time and by offering approaches for understanding TCs' practice and development through multiple data sources.

We have characterized soot particles measured in situ in a laminar co-flow ethylene-air diffusion flame using small-angle X-ray scattering (SAXS). The analysis includes temperature measurements made with coherent anti-Stokes Raman spectroscopy (CARS) and complements soot volume-fraction and maturity measurements made with laser-induced incandescence (LII). We compared the results of fits to the SAXS measurements using a unified model and a fractal core-shell model. Power-law parameters yielded by the unified model indicate that aggregates of primary particles are in the mass-fractal regime, whereas the primary particles are in the surface-fractal regime in the middle of the flame. Higher and lower in the flame, the primary-particle power-law parameter approaches 4, suggesting smooth primary particles. These trends are consistent with fits using the fractal core-shell model, which indicate that particles have an established core-shell structure in the middle of the flame and are internally homogeneous at higher and lower heights in the flame. Primary-particle size distributions derived using the fractal core-shell model demonstrate excellent agreement with distributions inferred from transmission electron microscopy (TEM) images in the middle of the flame. Higher in the flame, a second small mode appears in the size distributions, suggesting particle fragmentation during oxidation. Surface oxidation would explain (1) aggregate fragmentation and (2) loss of core-shell structure leading to smoother primary-particle surfaces by removal of carbon overlayers. SAXS measurements are much more sensitive to incipient and young soot particles than LII and demonstrate significant volume fraction from particles low in the flame where the LII signal is negligible.

Migration is a complex phenotypic trait with some species containing migratory and nonmigratory individuals. Such life history variation may be attributed in part to plasticity, epigenetics, or genetics. Although considered semianadromous, recent studies using otolith geochemistry have revealed life history variation within the critically endangered Delta Smelt. Broadly categorizable as migratory or freshwater residents, we examined Restriction site Associated DNA sequencing data to test for a relationship between genetic variation and migratory behaviors. As previously shown, we found no evidence for neutral population genetic structure within Delta Smelt; however, we found significant evidence for associations between genetic variants and life history phenotypes. Furthermore, discriminant analysis of principal components, hierarchical clustering, and machine learning resulted in accurate assignment of fish into the freshwater resident or migratory classes based on their genotypes. These results suggest the presence of adaptive genetic variants relating to life history variation within a panmictic population. Mechanisms that may lead to this observation are genotype dependent habitat choice and spatially variable selection, both of which could operate each generation and are not exclusive. Given that the population of cultured Delta Smelt are being used as a refugial population for conservation, as a supply for wild population supplementation, and currently represent the majority of all living individuals of this species, we recommend that the hatchery management strategy consider the frequencies of life history-associated alleles and how to maintain this important aspect of Delta Smelt biological variation while under captive propagation.

The mechanisms underlying the complications of mild traumatic brain injury, including post-concussion syndrome, post-impact catastrophic death, and delayed neurodegeneration remain poorly understood. This limited pathophysiological understanding has hindered the development of diagnostic and prognostic biomarkers and has prevented the advancement of treatments for the sequelae of mild traumatic brain injury. We aimed to characterize the early electrophysiological and neurovascular alterations following repetitive mild traumatic brain injury and sought to identify new targets for the diagnosis and treatment of individuals at risk of severe post-impact complications. We combined behavioural, electrophysiological, molecular, and neuroimaging techniques in a rodent model of repetitive mild traumatic brain injury. In humans, we used dynamic contrast-enhanced MRI to quantify blood-brain barrier dysfunction after exposure to sport-related concussive mild traumatic brain injury. Rats could clearly be classified based on their susceptibility to neurological complications, including life-threatening outcomes, following repetitive injury. Susceptible animals showed greater neurological complications and had higher levels of blood-brain barrier dysfunction, transforming growth factor β (TGFβ) signalling, and neuroinflammation compared to resilient animals. Cortical spreading depolarizations were the most common electrophysiological events immediately following mild traumatic brain injury and were associated with longer recovery from impact. Triggering cortical spreading depolarizations in mild traumatic brain injured rats (but not in controls) induced blood-brain barrier dysfunction. Treatment with a selective TGFβ receptor inhibitor prevented blood-brain barrier opening and reduced injury complications. Consistent with the rodent model, blood-brain barrier dysfunction was found in a subset of human athletes following concussive mild traumatic brain injury. We provide evidence that cortical spreading depolarization, blood-brain barrier dysfunction, and pro-inflammatory TGFβ signalling are associated with severe, potentially life-threatening outcomes following repetitive mild traumatic brain injury. Diagnostic-coupled targeting of TGFβ signalling may be a novel strategy in treating mild traumatic brain injury.

The Relict Dace is a small cyprinid and the only species in its genus, Relictus. It is naturally distributed in four drainage basins of central Nevada - Butte Valley, Ruby Valley, Steptoe Valley, and Goshute Valley. The species has experienced periods of isolation and connection within these four basins since the late Pliocene, with the last 100 years characterized by anthropogenic disturbance. To better inform conservation actions, we investigated range-wide and intra-basin genetic structure and diversity and conducted Fst outlier tests using RAD-sequencing. We found high levels of genetic structure and four main lineages on a broad scale corresponding primarily to geography, and on a very fine scale (

We have developed a strategy for distinguishing between small-angle X-ray scattering (SAXS) from gas-phase species and newly formed nanoparticles in mixed gas- and particle-phase reacting flows. This methodology explicitly accounts for temperature-dependent scattering from gases. We measured SAXS in situ in a sooting linear laminar partially premixed co-flow ethylene/air diffusion flame. The scattering signal demonstrates a downward curvature as a function of the momentum transfer (q) at q values of 0.2-0.57 Å-1. The q-dependent curvature is consistent with the Debye equation and the independent-atom model for gas-phase scattering. This behavior can also be modeled using the Guinier approximation and could be characterized as a Guinier knee for gas-phase scattering. The Guinier functional form can be fit to the scattering signal in this q range without a priori knowledge of the gas-phase composition, enabling estimation of the gas-phase contribution to the scattering signal while accounting for changes in the gas-phase composition and temperature. We coupled the SAXS measurements with in situ temperature measurements using coherent anti-Stokes Raman spectroscopy. This approach to characterizing the gas-phase SAXS signal provides a physical basis for distinguishing among the contributions to the scattering signal from the instrument function, flame gases, and nanoparticles. The results are particularly important for the analysis of the SAXS signal in the q range associated with particles in the size range of 1-6 nm.

The disruption caused by COVID-19 has accelerated many changes already emerging within work and higher education sectors. With the rapid move to online and distance learning models, the value of alternative forms of work-integrated learning (WIL), in spaces other than physical workplaces, has been realized. After the state of 'panic-gogy' where experimentation was rife, purposeful design of WIL in non-workplace settings now requires greater attention. Recent practice has shown that different models and approaches can still harness the authenticity of work tasks and therefore challenge dominant understandings and practices of designing and facilitating WIL. This paper advances the argument that the nature of work, itself, is morphing and, therefore, realizations of WIL also need to change including current conceptions of quality in WIL.

Practice-based pedagogies, such as representations of practice and approximations of practice, are increasingly common in mathematics teacher education. More needs to be known about how teacher candidates' (TCs') productions through such activities make visible the resources they bring to the work of teaching. In this paper, we highlight our use of "scripting tasks," through which secondary mathematics TCs produced dialogues of classroom interactions and rationales for those scripts in response to a provided classroom scenario. We share how analyses of TCs' scripts and rationales can make visible a range of resources that TCs bring to the work of teaching--tools and practices, vision and dispositions of teaching, and understandings of students and content (Hammerness et al., 2005)--that inform how they respond to student contributions in whole-class discussions as a focal teaching practice. We illustrate a rich example and framework for analyzing TCs' responses to scripting tasks and offer implications for how such analyses can support teacher educators and researchers to make claims about TCs' learning and inform decisions about supports for TCs' development.