Unique Variation Research Articles

A novel Cr3+-doped stannate far red phosphor for plant lighting: structure evolution, broad-narrow spectrum tuning and application prospect

Chemical unit cosubstitution is an effective strategy to regulate the luminescence properties of phosphors, and it has attracted huge attention in the last few years. Following the design principles of the match of effective ion radius, atomic valence equilibrium and stoichiometric substitution, the local structure of crystal can be well customized, which is beneficial to develop high-performance luminescent materials. In this work, Mg2+-Sn4+ sites were cosubstituted by Zn2+-Ti4+ ion pairs in Mg2SnO4: Cr3+, respectively, and the emission spectra was successfully serially tuned from broad-band to narrow-band along with a unique variation trend of blue shift first and then slightly red shift. The photoluminescence excitation (PLE), photoluminescence (PL) spectra, lifetime decay, Raman spectra and electron paramagnetic resonance (EPR) were used to analyze the mechanism of luminescence tuning. Based on the manipulation of local structure, the as-observed distinct luminescence tuning can be well understood by the crystal field theory, nephelauxetic effect and changed Cr3+ capacity in this phosphor. Moreover, the adjusted narrow-band far-red emission spectra peak at 732 nm, matching the characteristic absorption of plant phytochrome PFR, has broad application prospects in the field of plant growth lighting. In addition, light-regulated dwarf potted tomato experiments were carried out to verify the application of far-red light in plant growth.

Temporal Moment Localization via Natural Language by Utilizing Video Question Answers as a Special Variant and Bypassing NLP for Corpora

Temporal moment localization using natural language (TMLNL) is an emerging issue in computer vision for localizing a specific moment inside a long, untrimmed video. The goal of TMLNL is to obtain the video’s output moment, which is related to the input query in a substantial way. Previous research focused on the visual portion of TMLNL, such as objects, backdrops, and other visual attributes, but natural language processing (NLP) techniques were largely used for the textual portion. A long query requires sufficient context to properly localize moments within a long untrimmed video. Thus, as a consequence of not completely understanding how to handle queries, performances deteriorated, especially when the query was longer. In this paper, we treat the TMLNL challenge as a unique variation of VQA, which equally considers the visual elements by using our proposed VQA joint visual-textual framework (JVTF). However, we also manage complex and long input queries without employing natural language processing (NLP) by improving poorly graded to finely graded distinct granularity representations. Our suggested BCPN searches for insufficient context for long input queries using an approach called query handler (QH) and helps the JVTF find the most relevant moment. Previously, a recurrence of words was caused by increasing the number of encoding layers in transformers, LSTMs, and other NLP techniques; however, our QH ensured that repetition of word locations was reduced. The output of BCPN is combined with JVTF’s guided attention to further improve the end outcome. Therefore, we propose a novel bidirectional context predictor network (BCPN), in addition to a VQA joint visual-textual framework (JVTF), to address the equal importance of videos and queries. Through extensive experiments on three benchmark datasets, we show that the proposed BCPN outperforms the state-of-the-art methods by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$IoU = 0.3 (2.65 \%) $ </tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$IoU = 0.5 (2.49 \%)$ </tex-math></inline-formula> , and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$IoU = 0.7 (2.06 \%) $ </tex-math></inline-formula> .

Swimming in density-stratified fluid: study on a flapping foil

It is of interest to investigate how a swimming animal performs in a density-stratified fluid. This paper studies a simplified swimmer, a pitching NACA0015 airfoil, considering its locomotion in both homogeneous, or unstratified, and stratified fluid flows. A direct comparison is made between these two conditions through two-dimensional numerical simulations. Our numerical results show that the stratification modifies the dynamics of the pitching foil in both its wake structures and the drag force, or thrust, as well as its propulsive performance. We suggest that the effects of stratification on flapping performance or propulsive efficiency can be categorized according to the Froude number, or the level of stratification. First, in the range of high Froude numbers, notable modification of the flow structure can be observed, which however does not greatly affect the propulsive performance. Second, at a very low Froude number, i.e., Fr = 1, the propulsive efficiency drops markedly compared to its homogeneous counterpart, attributed to the pronounced internal waves induced by the strong stratification. Moreover, at a moderate Froude number Fr = 2, we find an increase in the propulsive efficiency, which can be explained by the unique variation in the wake structure. At A D = 2.50, the propulsive efficiency peaks at Fr = 2, with its efficiency 18.3% higher than its homogeneous counterpart, exhibiting a favourable influence of the stratification on a swimmer.

Phonon-mode-specific lattice dynamical coupling of carriers in semiconductors using Raman and optical spectroscopic techniques

We demonstrate a methodology for quantitative estimation of electron-phonon coupling (EPC) for each phonon mode taking base from second-order correction in polaron-energy resulting bandgap renormalization of the semiconductor by treating EPC as perturbation. This gives coupling constant (${\ensuremath{\alpha}}_{p}$) for the $p\mathrm{th}$ phonon mode in terms of phonon energy and renormalized bandgap due to EPC. These theoretical inferences are experimentally explored using combination of optical absorption and Raman spectroscopies for $\mathrm{\ensuremath{\Gamma}}$ phonons of temperature-varied GaN and ${\mathrm{TiO}}_{2}$; results reveal a systematic enhancement in ${\ensuremath{\alpha}}_{p}$ with temperature that exhibits unique percent variation of ${\ensuremath{\alpha}}_{p}$ for each mode. A higher percent change is observed for the mode known to exhibit greater coupling strength, thereby supporting the theoretical discussions. In this paper, we provide a simpler method to directly probe quantum level phonon-specific interactions with electrons, otherwise probed with much advanced techniques.

Combination of structural and functional connectivity explains unique variation in specific domains of cognitive function

The relationship between structural and functional brain networks has been characterised as complex: the two networks mirror each other and show mutual influence but they also diverge in their organisation. This work explored whether a combination of structural and functional connectivity can improve the fit of regression models of cognitive performance. Principal Component Analysis (PCA) was first applied to cognitive data from the Human Connectome Project to identify latent cognitive components: Executive Function, Self-regulation, Language, Encoding and Sequence Processing. A Principal Component Regression approach with embedded Step-Wise Regression (SWR-PCR) was then used to fit regression models of each cognitive domain based on structural (SC), functional (FC) or combined structural-functional (CC) connectivity. Executive Function was best explained by the CC model. Self-regulation was equally well explained by SC and FC. Language was equally well explained by CC and FC models. Encoding and Sequence Processing were best explained by SC. Evaluation of out-of-sample models’ skill via cross-validation showed that SC, FC and CC produced generalisable models of Language performance. SC models performed most effectively at predicting Language performance in unseen sample. Executive Function was most effectively predicted by SC models, followed only by CC models. Self-regulation was only effectively predicted by CC models and Sequence Processing was only effectively predicted by FC models. The present study demonstrates that integrating structural and functional connectivity can help explaining cognitive performance, but that the added explanatory value (in-sample) may be domain-specific and can come at the expense of reduced generalisation performance (out-of-sample).

Analysis of core asymmetries in inertial confinement fusion implosions using three-dimensional hot-spot reconstruction

Three-dimensional effects play a crucial role during the hot-spot formation in inertial confinement fusion (ICF) implosions. A data analysis technique for 3D hot-spot reconstruction from experimental observables has been developed to characterize the effects of low modes on 3D hot-spot formations. In nuclear measurements, the effective flow direction, governed by the maximum eigenvalue in the velocity variance of apparent ion temperatures, has been found to agree with the measured hot-spot flows for implosions dominated by mode ℓ=1. Asymmetries in areal-density (ρR) measurements were found to be characterized by a unique cosine variation along the hot-spot flow axis. In x-ray images, a 3D hot-spot x-ray emission tomography method was developed to reconstruct the 3D hot-spot plasma emissivity using a generalized spherical-harmonic Gaussian function. The gradient-descent algorithm was used to optimize the mapping between the projections from the 3D hot-spot emission model and the measured x-ray images along multiple views. This work establishes a platform to analyze 3D low-mode core asymmetries in ICF.

The impact of an additional year in high school on academic performance at university: Evidence from a policy experiment in Ghana

SummaryMotivationWhile education plays a fundamental role in economic development, the design of an appropriate educational structure, including duration of study at various levels, remains an issue of major policy debate in many low‐income countries. In Ghana, the issue of the length of high school education is an issue of ongoing policy debate.PurposeThis study estimates the effects of an additional year in senior high school (SHS) on academic performance at university level.Methods and approachUsing data from the two largest public universities in Ghana, the article exploits a unique natural experimental variation in the years of secondary education created by policy changes in pre‐university education in Ghana to estimate the impact of an additional year in SHS on a number of academic outcomes at university level.FindingsWe find that an additional year of SHS education has no impact on academic performance. We did not find any statistically significant difference in the likelihood of completing undergraduate studies in four years, or of graduating with a first‐class degree, or the final grade point average (GPA) of students who attended SHS for four years versus their counterparts who attended SHS for only three years. However, our descriptive analyses show that an additional year in SHS improves chances of students from less‐endowed SHS gaining admission to university, especially to health sciences programmes.Policy implicationsThe nuanced nature of the results suggests the need to further interrogate the policy on SHS duration in Ghana. This may help ensure that the implementation of the policy does not end up making some segment of the student population worse off.

Non-metallic inclusions and quality of pipe joints obtained by high-frequency electric resistance welding

An incisive analysis of studies of the most frequent defects of pipe joints obtained by high-frequency electric resistance welding (HFW) is included herein with particular focus on nonmetallic inclusions (NMIs), which are the cause of defects in such welded joints. Their composition, origin and methods of elimination under industrial conditions are discussed. In order to validate the nature of defects the interpretation procedure of the composition of NMIs detected in the discontinuities of welded joints has been developed. Examples of its application on the low-carbon line pipe steels of different grades X52&ndash;X56 are presented. The compositions of NMIs found in 64 defects of welded joints of A 516-55 (09G2S) steel pipes are summarized. These compositions significantly differ from each other and correspond to the different nature of NMIs: indigenous deoxidation products based on spinel MgO∙Al2O3 (8 %), products of steel modification by calcium (62 %), exo-indigenous NMIs with residuals of mould flux (4 %) or MgO (8 %) and indi-exogenous NMIs based on MgO (18 %). The unique variation ranges of the main elements included in these groups of NMIs are used for automated determination of their origin when carrying out metallographic examination of defects by means of the Thixomet image analyzer in the conditions of factory practice. The detailed origin of NMIs makes it possible to indicate the exact location in the technology of ladle treatment and steel casting for their improvement and to enhance on this basis the quality of line pipe joints obtained by HFW.

Mr. and Mrs. Crab: How Can We Tell Them Apart?

Male and female mud crabs may look alike at first glance, but clear differences in physical characteristics exist. These variations between sexes are known as sexual dimorphism. Sexual dimorphism may help species to survive in their environments. We found that three mud crab species (orange, green, and purple mud crabs) showed similar patterns of sexual dimorphism. Males generally have larger body and claw sizes, whereas females have larger abdomens. Orange mud crabs also have a unique body shape variation compared to green and purple mud crabs. All mud crabs have spines along the top edge of their shells, and scientists have numbered these spines to identify them. Unlike the green and purple species, orange mud crabs are wider at spine 8 than spine 9. Sexual dimorphism in crabs might be linked to how they reproduce and where they live.

Loss of anthocyanidin synthase gene is associated with white flowers of Salvia miltiorrhiza Bge. f. alba, a natural variant of S. miltiorrhiza.

SmANS deletion leads to white flower mutation in Salvia miltiorrhiza. SmANS deletion leads to white flower mutation in Salvia miltiorrhiza. Abstract Salvia miltiorrhiza is an essential traditional Chinese medicine (TCM) with purple flowers, and S. miltiorrhiza Bge. f. alba is a unique intraspecific variation with white flowers. The molecular mechanism of flower color formation in S. miltiorrhiza will provide vital information for the variation and evolution. Here, we performed HPLC, transcriptomic, and re-sequencing analyses of purple-flowered S. miltiorrhiza line 'Zihua105' (ZH105) and white-flowered S. miltiorrhiza Bge. f. alba line 'Baihua18' (BH18). Delphinidin was the most anthocyanidin in ZH105, which become the main different between ZH105 vs. BH18 flowers. Transcriptome analysis revealed 299 differentially expressed genes (DEGs). SmANS, the anthocyanidin synthase gene in the down-stream anthocyanin biosynthesis pathway, was significantly expressed in ZH105 corollas, suggesting it might play a key role in white petal formation. Whole-genome re-sequencing revealed that a 6.75kb segment located on chromosome 5, which contains the complete sequence of the SmANS genes, was lost in BH18 and another S. miltiorrhiza Bge. f. alba line. In contrast, the other five purple-flowered S. miltiorrhiza lines both possessed this segment. Further molecular marker identification also confirmed that wild S. miltiorrhiza Bge. f. alba lines lost regions that contained a complete or important part of SmANS sequences. Subsequently, the research showed that the deletion mutant of SmANS genes resulted in the natural white flower color variant of S. miltiorrhiza.

Know Time to Die – Integrity Checking for Zero Trust Chiplet-based Systems Using Between-Die Delay PUFs

Industry trends are moving toward increasing use of chiplets as a replacement for monolithic fabrication in many modern chips. Each chiplet is a separately-produced silicon die, and a system-on-chip (SoC) is created by packaging the chiplets together on a silicon interposer or bridge. Chiplets enable IP reuse, heterogeneousintegration, and better ability to leverage cost-appropriate process nodes. Yet, creating systems from separately produced components also brings security risks to consider, such as the possibility of die swapping, or susceptibility to interposer probing or tampering. In a zero-trust security posture, a chiplet should not blindly assume it is operating in a friendly environment.In this paper we propose a delay-based PUF for chiplets to verify system integrity. Our technique allows a single chiplet to initiate a protocol with its neighbors to measure unique variations in the propagation delays of incoming signals as part of an integrity check. We prototype our design on Xilinx Ultrascale+ FPGAs, which are constructed as multi-die systems on a silicon interposer, and which also emulate the general features of other industrial chiplet interfaces. We perform experiments on, and compare data from, dozens of Ultrascale+ FPGAs by making use of Amazon’s Elastic Compute Cloud (EC2) F1 instances as a testing platform. The PUF cells are shown to reject clock and temperature variation as common mode, and each cell produces approximately 5 ps of unique delay variation. For a design with 144 PUF cells, we measure the mean within-class and between-class distances to be 68.3 ps and 847.7 ps, respectively. The smallest between-class distance of 686.0 ps exceeds the largest within-class distance of 124.0 ps by more than 5x under nominal conditions, and the PUF is shown to be resilient to environmental changes. Our findings indicate the PUF can be used for authentication, and is potentially sensitive enough to detect picosecond-scale timing changes due to tampering.

We get by with a little help from our friends: shared adaptive variation provides a bridge to novel ecological specialists during adaptive radiation.

Adaptive radiations involve astounding bursts of phenotypic, ecological and species diversity. However, the microevolutionary processes that underlie the origins of these bursts are still poorly understood. We report the discovery of an intermediate C. sp. ‘wide-mouth’ scale-eating ecomorph in a sympatric radiation of Cyprinodon pupfishes, illuminating the transition from a widespread algae-eating generalist to a novel microendemic scale-eating specialist. We first show that this ecomorph occurs in sympatry with generalist C. variegatus and scale-eating specialist C. desquamator on San Salvador Island, Bahamas, but is genetically differentiated, morphologically distinct and often consumes scales. We then compared the timing of selective sweeps on shared and unique adaptive variants in trophic specialists to characterize their adaptive walk. Shared adaptive regions swept first in both the specialist desquamator and the intermediate ‘wide-mouth’ ecomorph, followed by unique sweeps of introgressed variation in ‘wide-mouth’ and de novo variation in desquamator. The two scale-eating populations additionally shared 9% of their hard selective sweeps with the molluscivore C. brontotheroides, despite no single common ancestor among specialists. Our work provides a new microevolutionary framework for investigating how major ecological transitions occur and illustrates how both shared and unique genetic variation can provide a bridge for multiple species to access novel ecological niches.

Multifunctional Textile Electronic with Sensing, Energy Storing, and Electrothermal Heating Capabilities.

The development of wearable devices has stimulated significant engineering and technologies of textile electronics (TEs). Improving sensing, energy-storing, and electro-heating capabilities of TEs is still challenging but crucial for their practical applications. Herein, a drip-coating method that constructs a dense β-FeOOH scaffold on a nylon strip for enhancing polypyrrole loading is proposed, which facilitates the fabrication of highly conductive and hydrophobic PFCNS (polypyrrole/β-FeOOH/nylon strip). The space provided by the β-FeOOH scaffold increases the mass of polypyrrole on fibers from 1.1 (polypyrrole/nylon strip) to 3.0 mg cm-2 (polypyrrole/β-FeOOH/nylon strip), which decreases the resistance from 104.96 to 34.29 Ω cm-1. The PFCNS exhibits a linear elastic modulus of 0.758 MPa within 150% strain, performs a unique resistance variation mechanism, and enables great sensing capability with rapid response time (140 ms), long durability (10,000 stretching-recovering), and effective movement monitoring (e.g., breathing, back bending, jumping). The sensing signals for knee bending have been analyzed in detail by combining with both stretching and pressing response mechanisms. The PFCNS electrode attains a diffusion-controlled capacitance of 574 mF cm-2 and discharging-capacitance of 916 mF cm-2. Furthermore, an interdigitally parallel connection is proposed, which assists the PFCNS heater in achieving high temperature (84 °C) at a low voltage (4 V). This work provides a simple route for nylon-based TEs and promises satisfactory application in wearable sensors, power sources, and heaters.

Soft maximin estimation for heterogeneous data

AbstractExtracting a common robust signal from data divided into heterogeneous groups is challenging when each group—in addition to the signal—contains large, unique variation components. Previously, maximin estimation was proposed as a robust method in the presence of heterogeneous noise. We propose soft maximin estimation as a computationally attractive alternative aimed at striking a balance between pooled estimation and (hard) maximin estimation. The soft maximin method provides a range of estimators, controlled by a parameter , that interpolates pooled least squares estimation and maximin estimation. By establishing relevant theoretical properties we argue that the soft maximin method is statistically sensible and computationally attractive. We demonstrate, on real and simulated data, that soft maximin estimation can offer improvements over both pooled OLS and hard maximin in terms of predictive performance and computational complexity. A time and memory efficient implementation is provided in the R package SMME available on CRAN.

Drag force on a circular cylinder in stratified flow: A two-dimensional numerical study

Using two-dimensional numerical simulations, we investigate a circular cylinder in a stratified flow with a pycnocline of a smooth density profile. We are particularly concerned about the difference between stratified flows and their homogeneous, or unstratified, counterparts in drag coefficients. It is well known that the characteristics of a stratified flow depend on the Reynolds number Re and the internal Froude number Fr. First, we change the incoming flow velocity, with the Reynolds number and the internal Froude number varying simultaneously, in the ranges of 76≤Re≤579 and 0.14≤Fr≤1.046, respectively. We find that the flow experiences a sequence of flow patterns, namely “multiple centerline structures,” “isolated mixed regions,” and “vortex shedding,” as we increase this combination, agreeing well with the previous experiments in the low Re and Fr ranges. Meanwhile, the mean drag coefficient decreases, and it drops below the value for a homogeneous state as an empirical stability parameter, k, drops below unity, indicating the transition from a lee-wave dominant wake to an unsteady, vortex shedding wake. This unique variation of drag coefficient is more clearly shown in another situation, when we fix the Reynolds number at Re = 234 while varying the Froude number within 0.094≤Fr≤4.192. In such a situation, we observe a stable “double eddy” pattern at Fr = 1.87, around which a minimum of mean drag coefficient is reached. At this critical point, we understand that the stratification in the flow inhibits lee-side separation, while the internal waves have not yet played a significant role. Although we observe turbulence-like, strong mixing regions in the far downstream wake for some specific cases, it is argued that the current two-dimensional simulations might not be able to resolve the high Reynolds number or high Froude number cases.

Association of mast-cell-related conditions with hypermobile syndromes: a review of the literature.

Ehlers–Danlos syndrome (EDS) is a group of related connective tissue disorders consisting of 13 subtypes, each with its own unique phenotypic and genetic variation. The overlap of symptoms and multitude of EDS variations makes it difficult for patients to achieve a diagnosis early in the course of their disease. The most common form, hypermobile type EDS (hEDS) and its variant, hypermobile spectrum disorder (HSD), are correlated with rheumatologic and inflammatory conditions. Evidence is still needed to determine the pathophysiology of hEDS; however, the association among these conditions and their prevalence in hEDS/HSD may be explained through consideration of persistent chronic inflammation contributing to a disruption of the connective tissue. Aberrant mast cell activation has been shown to play a role in disruption of connective tissue integrity through activity of its mediators including histamine and tryptase which affects multiple organ systems resulting in mast cell activation disorders (MCAD). The overlap of findings associated with MCAD and the immune-mediated and rheumatologic conditions in patients with hEDS/HSD may provide an explanation for the relationship among these conditions and the presence of chronic inflammatory processes in these patients. It is clear that a multidisciplinary approach is required for the treatment of patients with EDS. However, it is also important for clinicians to consider the summarized symptoms and MCAD-associated characteristics in patients with multiple complaints as possible manifestations of connective tissue disorders, in order to potentially aid in establishing an early diagnosis of EDS.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12026-022-09280-1.

Tracking Changes in the Spring Barley Gene Pool in Poland during 120 Years of Breeding.

This study was undertaken to investigate the diversity and population structure of 83 spring barley (Hordeum vulgare L.) cultivars, which corresponded to 120 years of this crop’s breeding in Poland. The analysis was based on 11,655 DArTseq-derived SNPs evenly distributed across seven barley chromosomes. Five groups were assigned in the studied cultivars according to the period of their breeding. A decrease in observed heterozygosity within the groups was noted along with the progress in breeding, with a simultaneous increase in the inbreeding coefficient value. As a result of breeding, some of the unique allelic variation present in old cultivars was lost, but crosses with foreign materials also provided new alleles to the barley gene pool. It is important to mention that the above changes affected different chromosomes to varying degrees. The internal variability of the cultivars ranged from 0.011 to 0.236. Internal uniformity was lowest among the oldest cultivars, although some highly homogeneous ones were found among them. This is probably an effect of genetic drift or selection during their multiplications and regenerations in the period from breeding to the time of analysis. The population genetic structure of the studied group of cultivars appears to be quite complex. It was shown that their genetic makeup consists of as many as eleven distinct gene pools. The analysis also showed traces of directed selection on chromosomes 3H and 5H. Detailed data analysis confirmed the presence of duplicates for 11 cultivars. The performed research will allow both improvement of the management of barley genetic resources in the gene bank and the reuse of this rich and forgotten variability in breeding programs and research.

Comparative Genomics of Disease and Carriage Serotype 1 Pneumococci.

The isolation of Streptococcus pneumoniae serotypes in systemic tissues of patients with invasive disease versus the nasopharynx of healthy individuals with asymptomatic carriage varies widely. Some serotypes are hyper-invasive, particularly serotype 1, but the underlying genetics remain poorly understood due to the rarity of carriage isolates, reducing the power of comparison with invasive isolates. Here, we use a well-controlled genome-wide association study to search for genetic variation associated with invasiveness of serotype 1 pneumococci from a serotype 1 endemic setting in Africa. We found no consensus evidence that certain genomic variation is overrepresented among isolates from patients with invasive disease than asymptomatic carriage. Overall, the genomic variation explained negligible phenotypic variability, suggesting a minimal effect on the disease status. Furthermore, changes in lineage distribution were seen with lineages replacing each other over time, highlighting the importance of continued pathogen surveillance. Our findings suggest that the hyper-invasiveness is an intrinsic property of the serotype 1 strains, not specific for a “disease-associated” subpopulation disproportionately harboring unique genomic variation.

Safety Squat Bar Squat Technique and Biomechanics-Driven Programming

ABSTRACT The safety squat bar squat (SSBS) is a unique squat variation performed with its namesake barbell. In addition to describing proper SSBS technique, this column reviews SSBS biomechanics, criteria for exercise performance, programming opportunities for special populations, and descriptions of 3 additional exercise variations with suggestions for use.

A genomic perspective on the conservation status of the endangered Nashville crayfish (Faxonius shoupi)

The Nashville crayfish (Faxonius shoupi, Hobbs 1948) was federally listed as an endangered species in 1986 due to its limited distribution in the Mill Creek watershed; this waterway lies in the rapidly developing Nashville basin and has experienced habitat degradation due to agricultural run-off, contamination, and urban development. Recovery efforts, including dam removal and restoration of riparian zones, have improved conditions in Mill Creek and F. shoupi has increased in numbers and recolonized extirpated stream segments. However, a history of demographic bottlenecks and restricted gene flow may have negatively impacted the long-term recovery of this species. A recently discovered population of F. shoupi in a disjunct segment of the Lower Tennessee River at the Pickwick Tailwater may provide an additional source of genetic variation. Uncertainty surrounding the origins of the Pickwick population and its taxonomic relationship to F. shoupi in Mill Creek raises questions about the conservation and management implications of this population. We used mitochondrial sequencing and SNP genotyping to assess genetic variation and connectivity of F. shoupi in the Mill Creek drainage and to investigate the taxonomy and demographic history of the newly discovered population at Pickwick. We found substantial genetic variation and evidence of connectivity for samples throughout Mill Creek for both mitochondrial and genome-wide SNPs. Our results also suggest a recently severed connection between crayfish in Pickwick and Mill Creek. Unique mitochondrial haplotypes and SNP variation in the Pickwick population highlight the need for prioritizing this population in future conservation and management plans for this species.