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Next-generation X-ray satellite telescopes such as XRISM, NewAthena and Lynx will enable observations of exotic astrophysical sources at unprecedented spectral and spatial resolution. Proper interpretation of these data demands that the accuracy of the models is at least within the uncertainty of the observations. One set of quantities that might not currently meet this requirement is transition energies of various astrophysically relevant ions. Current databases are populated with many untested theoretical calculations. Accurate laboratory benchmarks are required to better understand the coming data. We obtained laboratory spectra of X-ray lines from a silicon plasma at an average spectral resolving power of $\sim$7500 with a spherically bent crystal spectrometer on the Z facility at Sandia National Laboratories. Many of the lines in the data are measured here for the first time. We report measurements of 53 transitions originating from the K-shells of He-like to B-like silicon in the energy range between $\sim$1795 and 1880 eV (6.6–6.9 Å). The lines were identified by qualitative comparison against a full synthetic spectrum calculated with ATOMIC. The average fractional uncertainty (uncertainty/energy) for all reported lines is ${\sim}5.4 \times 10^{-5}$. We compare the measured quantities against transition energies calculated with RATS and FAC as well as those reported in the NIST ASD and XSTAR’s uaDB. Average absolute differences relative to experimentally measured values are 0.20, 0.32, 0.17 and 0.38 eV, respectively. All calculations/databases show good agreement with the experimental values; NIST ASD shows the closest match overall.
A model is proposed for the one-dimensional spectrum and streamwise Reynolds stress in pipe flow for arbitrarily large Reynolds numbers. Constructed in wavenumber space, the model comprises four principal contributions to the spectrum: streaks, large-scale motions, very-large-scale motions and incoherent turbulence. It accounts for the broad and overlapping spectral content of these contributions from different eddy types. The model reproduces well the broad structure of the premultiplied one-dimensional spectrum of the streamwise velocity, although the bimodal shape that has been observed at certain wall-normal locations, and the $-5/3$ slope of the inertial subrange, are not captured effectively because of the simplifications made within the model. Regardless, the Reynolds stress distribution is well reproduced, even within the near-wall region, including key features of wall-bounded flows such as the Reynolds number dependence of the inner peak, the formation of a logarithmic region, and the formation of an outer peak. These findings suggest that many of these features arise from the overlap of energy content produced by both inner- and outer-scaled eddy structures combined with the viscous-scaled influence of the wall. The model is also used to compare with canonical turbulent boundary layer and channel flows, and despite some differences being apparent, we speculate that with only minor modifications to its coefficients, the model can be adapted to these flows as well.
This study examined whether supplementation with collagen peptides (CP) affects appetite and post-exercise energy intake in healthy active females.
In this randomised, double-blind crossover study, 15 healthy females (23 ± 3 y) consumed 15 g/day of CP or a taste matched non-energy control (CON) for 7 days. On day 7, participants cycled for 45 min at ∼55% Wmax, before consuming the final supplement. Sixty min post supplementation an ad libitum meal was provided, and energy intake recorded. Subjective appetite sensations were measured daily for 6 days (pre- and 30 min post-supplement), and pre (0 min) to 280 min post-exercise on day 7. Blood glucose and hormone concentrations (total ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY), cholecystokinin (CCK), dipeptidyl peptidase-4 (sDPP4), leptin, and insulin, were measured fasted at baseline (day 0), then pre-breakfast (0 min), post-exercise (100 min), post-supplement (115, 130, 145, 160 min) and post-meal (220, 280 min) on day 7.
Ad-libitum energy intake was ∼10% (∼41kcal) lower in the CP trial (P=0.037). There was no difference in gastrointestinal symptoms or subjective appetite sensations throughout the trial (P≥0.412). Total plasma GLP-1 (area under the curve, CON: 6369±2330; CP: 9064±3021 pmol/L; P<0.001) and insulin (+80% at peak) were higher after CP (P<0.001). Plasma ghrelin and leptin were lower in CP (condition effect; P≤0.032). PYY, CCK, sDPP4 and glucose were not different between CP and placebo (P≥0.100).
CP supplementation following exercise increased GLP-1 and insulin concentrations and reduced ad libitum energy intake at a subsequent meal in physically active females.
The stars of the Milky Way carry the chemical history of our Galaxy in their atmospheres as they journey through its vast expanse. Like barcodes, we can extract the chemical fingerprints of stars from high-resolution spectroscopy. The fourth data release (DR4) of the Galactic Archaeology with HERMES (GALAH) Survey, based on a decade of observations, provides the chemical abundances of up to 32 elements for 917 588 stars that also have exquisite astrometric data from the Gaia satellite. For the first time, these elements include life-essential nitrogen to complement carbon, and oxygen as well as more measurements of rare-earth elements critical to modern-life electronics, offering unparalleled insights into the chemical composition of the Milky Way. For this release, we use neural networks to simultaneously fit stellar parameters and abundances across the whole wavelength range, leveraging synthetic grids computed with Spectroscopy Made Easy. These grids account for atomic line formation in non-local thermodynamic equilibrium for 14 elements. In a two-iteration process, we first fit stellar labels to all 1 085 520 spectra, then co-add repeated observations and refine these labels using astrometric data from Gaia and 2MASS photometry, improving the accuracy and precision of stellar parameters and abundances. Our validation thoroughly assesses the reliability of spectroscopic measurements and highlights key caveats. GALAH DR4 represents yet another milestone in Galactic archaeology, combining detailed chemical compositions from multiple nucleosynthetic channels with kinematic information and age estimates. The resulting dataset, covering nearly a million stars, opens new avenues for understanding not only the chemical and dynamical history of the Milky Way but also the broader questions of the origin of elements and the evolution of planets, stars, and galaxies.
This article investigates personal and public facets of the life and work of Hannah Whitall Smith (1832–1911) as a lens through which to explore the complexities of marginalization and belonging within the late nineteenth-century Holiness movement. Despite her significant contributions as a lay Christian leader, prolific author and social activist, Smith’s legacy remains largely understudied. Examining selections from her extensive collected works, including correspondence and Smith’s file of ‘fanaticisms’, this article investigates how supposed margins and peripheries are not places of obscurity or insignificance, but fertile contexts of religious dialogue and innovation.
Community-engaged partnerships (community/academia/government) can play a role in developing effective protocols that address public health crises. Systemic racism, prioritization of money over humanity, and the repression of the local democratic processes through the State of Michigan Emergency Manager Law (Order of Act 439) all played a role in the Flint Water Crisis. Despite decades of collaboration between Flint-based community organizations and academic institutions, ways to navigate such crises and conduct relevant research were ineffective.
Methods:
The Michigan Institute for Clinical and Health Research Community Engagement program at the University of Michigan and Flint’s Community Based Organization Partners co-developed the Research Readiness and Partnership Protocol (R2P2) to provide community-engaged recommendations that inform a rapid research response to public health emergencies. The R2P2 Workgroup conducted an extensive literature review and key interviews to inform protocol development.
Results:
This manuscript provides an overview of the Workgroup’s methods, key interview findings, and the main principles identified. Detailed recommendations and key elements to address prior to and during a crisis will be presented including methods for: establishing and maintaining trust, ensuring transparency, supporting clear communication, establishing a “front door” to academic institutions including a means to “sound the alarm,” addressing academic incentives, achieving equitable resource sharing, and addressing systemic racism.
Conclusion:
This manuscript of community perspectives provides essential elements to develop meaningful community-academic research partnerships to address public health crises impacting communities, particularly communities of color. Furthermore, this work highlights an opportunity for greater acknowledgment and utilization of community-based participatory research (CBPR) by academic institutions.
We examine the least squares approximation C to a symmetric matrix B, when all diagonal elements get weight w relative to all nondiagonal elements. WhenB has positivity p and C is constrained to be positive semi-definite, our main result states that, when w ≥1/2, then the rank of C is never greater than p, and when w ≤1/2 then the rank of C is at least p. For the problem of approximating a given n × n matrix with a zero diagonal by a squared-distance matrix, it is shown that the sstress criterion leads to a similar weighted least squares solution with w =(n+2)/4; the main result remains true. Other related problems and algorithmic consequences are briefly discussed.
Edited by
R. A. Bailey, University of St Andrews, Scotland,Peter J. Cameron, University of St Andrews, Scotland,Yaokun Wu, Shanghai Jiao Tong University, China
Edited by
R. A. Bailey, University of St Andrews, Scotland,Peter J. Cameron, University of St Andrews, Scotland,Yaokun Wu, Shanghai Jiao Tong University, China
Eigenvalues of the Laplacian matrix of a graph have been widely used in studying connectivity and expansion properties of networks, and also in analyzing random walks on a graph. Independently, statisticians introduced various optimality criteria in experimental design, the goal being to obtain more accurate estimates of quantities of interest in an experiment. It turns out that the most popular of these optimality criteria for block designs are determined by the Laplacian eigenvalues of the concurrence graph, or of the Levi graph, of the design. The most important optimality criteria, called A (average), D (determinant) and E (extreme), are related to the conductance of the graph as an electrical network, the number of spanning trees, and the isoperimetric properties of the graphs, respectively. The number of spanning trees is also an evaluation of the Tutte polynomial of the graph, and is the subject of the Merino–Welsh conjecture relating it to acyclic and totally cyclic orientations, of interest in their own right. This chapter ties these ideas together, building on the work in [4] and [5].
Edited by
R. A. Bailey, University of St Andrews, Scotland,Peter J. Cameron, University of St Andrews, Scotland,Yaokun Wu, Shanghai Jiao Tong University, China
Edited by
R. A. Bailey, University of St Andrews, Scotland,Peter J. Cameron, University of St Andrews, Scotland,Yaokun Wu, Shanghai Jiao Tong University, China
Edited by
R. A. Bailey, University of St Andrews, Scotland,Peter J. Cameron, University of St Andrews, Scotland,Yaokun Wu, Shanghai Jiao Tong University, China
Edited by
R. A. Bailey, University of St Andrews, Scotland,Peter J. Cameron, University of St Andrews, Scotland,Yaokun Wu, Shanghai Jiao Tong University, China
Edited by
R. A. Bailey, University of St Andrews, Scotland,Peter J. Cameron, University of St Andrews, Scotland,Yaokun Wu, Shanghai Jiao Tong University, China
This collection of four short courses looks at group representations, graph spectra, statistical optimality, and symbolic dynamics, highlighting their common roots in linear algebra. It leads students from the very beginnings in linear algebra to high-level applications: representations of finite groups, leading to probability models and harmonic analysis; eigenvalues of growing graphs from quantum probability techniques; statistical optimality of designs from Laplacian eigenvalues of graphs; and symbolic dynamics, applying matrix stability and K-theory. An invaluable resource for researchers and beginning Ph.D. students, this book includes copious exercises, notes, and references.
The escalating threat of antimicrobial resistance (AMR) necessitates impactful, reproducible, and scalable antimicrobial stewardship strategies. This review addresses the critical need to enhance the quality of antimicrobial stewardship intervention research. We propose five considerations for authors planning and evaluating antimicrobial stewardship initiatives. Antimicrobial stewards should consider the following mnemonic ABCDE: (A) plan Ahead using implementation science; (B) Be clear and thoroughly describe the intervention by using the TidIER checklist; (C) Use a Checklist to comprehensively report study components; (D) Select a study Design carefully; and (E) Assess Effectiveness and implementation by selecting meaningful outcomes. Incorporating these recommendations will help strengthen the evidence base of antimicrobial stewardship literature and support optimal implementation of strategies to mitigate AMR.
A new nematode genus and species, Paraspiralatus sakeri , is described from the stomach of a wild-caught, female saker falcon in Saudi Arabia. This spirurid differs from the nearest genus and species Spiralatus baeri Chabaud, Brygoo & Durette, 1963 in the shape of the pseudolabia, shape of the buccal capsule and absence of a large cephalic vesicle. In addition, third stage spirurid larvae were recovered for the first time from subcutaneous tissues of two houbara bustards. These had died in the Rahim Yar Khan Rehabilitation Center (Houbara Foundation International, Lahore, Pakistan) in Pakistan and were examined at the National Avian Research Center in the United Arab Emirates. The morphology of the larvae and host pathology are described. Comparative studies with the adult spirurids from the saker falcon showed each to have similar cephalic and pharyngeal morphological features to the adults described indicating they are probably the same species. Spirurid nematodes of the suborder Spirurina normally have an arthropod intermediate host. In view of the host, the site from which the larvae were recovered and the fact that this is a rare occurrence, the houbara bustard is considered to be a paratenic host.
OBJECTIVES/GOALS: Communities of color often report that their concerns are ignored and desire a means to facilitate effective community-academic engagement, especially during a crisis. The objective is to share lessons learned and challenges faced in the development of an online portal designed to meet this need. METHODS/STUDY POPULATION: The Michigan Institute for Clinical & Health Research (MICHR) worked with community and academics to develop an online tool, the Michigan Research Engaging the Academy and Community in Health (M-REACH) platform. The community-engaged research (CEnR) project involved conducting qualitative interviews exploring connectivity to community and academic organizations and pilot testing of the novel platform. Following development, efforts were made to implement the statewide use of M-REACH. We will report on the challenges encountered and lessons learned from development and optimization of the platform. RESULTS/ANTICIPATED RESULTS: Authors will review the timeline of the launch of M-REACH. Steps to promote engagement of the locally developed platform to statewide utilization will be shared. Challenges encountered with scaling, matching the needs of differing communities both rural and urban, and navigating connections between remote geographies will be presented. Lessons learned and potential solutions will be discussed. DISCUSSION/SIGNIFICANCE: M-REACH can connect partners by increasing understanding of the CEnR process, enhancing alignment, and building a foundation for well-functioning research partnerships. Further work is required to address the challenges encountered in development and implementation.
OBJECTIVES/GOALS: Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by dysregulated collagen accumulation in the lung parenchyma. Our goal is to investigate the role of O-linked N-Acetylglucosamine (O-GlcNAc) transferase (OGT) in pulmonary fibrosis to ultimately discover novel therapies for fibrosis resolution. METHODS/STUDY POPULATION: Lung tissue from IPF and non-IPF donors was subjected to immunohistochemistry (IHC) to assess O-GlcNAc levels. Primary human lung fibroblasts were treated with OGT or O-GlcNAcase (OGA) inhibitors followed by transforming growth factor-beta 1 (TGF-β1) stimulation to assess O-GlcNAc regulation of fibroblast-to-myofibroblast transition (FMT) markers [alpha smooth muscle actin (α-SMA) and type 1 and type 3 collagen (COL1α1, COL3α1)] In Drosophila melanogaster, OGT knockdown (KD)/overexpression (OE) was conditionally induced to assess pericardin, a type IV collagen-like protein, regulation by immunofluorescence. Lastly, a mouse model of bleomycin-induced pulmonary fibrosis was examined following OGT KD and assessed for fibrosis resolution via histology, hydroxyproline assay, and western blotting. RESULTS/ANTICIPATED RESULTS: O-GlcNAc staining was increased in IPF lung tissue compared to non-IPF control lungs. In primary human lung fibroblasts, TGF-α1 administration resulted in increased FMT markers (α-SMA, COL1α1, and COL3α1), which were reduced or increased by OGT or OGA inhibition, respectively. Genetic manipulation in the Drosophila models showed decreased pericardin expression with OGT KD compared to the wild-type, whereas OGT OE increased pericardin compared to control. Additionally, OGT KD in bleomycin treated aged mice resulted in reduced collagen levels at the transcript and protein level and concurrent fibrosis resolution as assessed by Masson’s trichrome staining and total hydroxyproline analysis. Collectively, showing OGT/O-GlcNAc regulating collagen in fibrosis resolution. DISCUSSION/SIGNIFICANCE: These data suggest that the OGT/O-GlcNAc axis regulates collagen deposition in pulmonary fibrosis, and we show that O-GlcNAc is implicated in the pathogenesis of IPF. We identified OGT as a therapeutic target to overcome current drug limitations, opening new horizons for biomedical treatment.