Publications by authors named "Bower D"

Cephalopods produce dynamic colors and skin patterns for communication and camouflage via stratified networks of neuronally actuated yellow, red, and brown chromatophore organs, each filled with thousands of pigment granules. While compositional analysis of chromatophore granules in Doryteuthis pealeii reveals the pigments as ommochromes, the ultrastructural features of the granules and their effects on bulk coloration have not been explored. To investigate this, we isolated granules from specific colored chromatophores and imaged them using multiple modalities.

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Interactions between magma oceans and overlying atmospheres on young rocky planets leads to an evolving feedback of outgassing, greenhouse forcing, and mantle melt fraction. Previous studies have predominantly focused on the solidification of oxidized Earth-similar planets, but the diversity in mean density and irradiation observed in the low-mass exoplanet census motivate exploration of strongly varying geochemical scenarios. We aim to explore how variable redox properties alter the duration of magma ocean solidification, the equilibrium thermodynamic state, melt fraction of the mantle, and atmospheric composition.

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If ocean-derived materials are present at Europa's surface, they would represent accessible records of ocean chemistry and habitability, but such materials would be further processed by Europa's harsh radiation environment. In this study, saturated fatty acids were precipitated onto a Europa-relevant hydrated magnesium sulfate and exposed to gamma radiation doses up to 2 MGy at -196°C. Alkane chains, with carbon numbers one less than those of the starting fatty acids, were the most abundant radiolysis products in solvent and thermal extracts analyzed by gas chromatography mass spectrometry.

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Data-driven approaches have achieved great success in various medical image analysis tasks. However, fully-supervised data-driven approaches require unprecedentedly large amounts of labeled data and often suffer from poor generalization to unseen new data due to domain shifts. Various unsupervised domain adaptation (UDA) methods have been actively explored to solve these problems.

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A major objective of the Mars 2020 mission is to sample rocks in Jezero crater that may preserve organic matter for later return to Earth. Using an ultraviolet Raman and luminescence spectrometer, the Perseverance rover detected luminescence signals with maximal intensities at 330 to 350 nanometers and 270 to 290 nanometers that were initially reported as consistent with organics. Here, we test the alternative hypothesis that the 330- to 350-nanometer and 270- to 290-nanometer luminescence signals trace Ce in phosphate and silicate defects, respectively.

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Frozen water bodies provide a physiological challenge to fauna by physically limiting access to atmospheric oxygen. To tolerate low temperatures, reptiles use brumation as a physiological strategy in winter. Cryptodira vary in their tolerance to freezing conditions but the extent of tolerance in pleurodirans is largely unknown.

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Mars has been exposed to ionizing radiation for several billion years, and as part of the search for life on the Red Planet, it is crucial to understand the impact of radiation on biosignature preservation. Several NASA and ESA missions are looking for evidence of ancient life in samples collected at depths shallow enough that they have been impacted by galactic cosmic rays (GCRs). In this study, we exposed a diverse set of Mars analog samples to 0.

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Article Synopsis
  • The study aimed to assess the severity of COVID-19 using a new AI model called AssessNet-19, comparing it to traditional single-class models and expert radiologists' assessments in chest CT scans.
  • The model was developed through a two-stage process involving manual segmentation of lung lesions and the extraction of radiomic features, ultimately classifying disease severity using a machine learning approach.
  • AssessNet-19 outperformed radiologists and single-class models in accuracy, achieving a high F1-score and demonstrating strong consistency in quantifying disease extent.
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While blood gene signatures have shown promise in tuberculosis (TB) diagnosis and treatment monitoring, most signatures derived from a single cohort may be insufficient to capture TB heterogeneity in populations and individuals. Here we report a new generalized approach combining a network-based meta-analysis with machine-learning modeling to leverage the power of heterogeneity among studies. The transcriptome datasets from 57 studies (37 TB and 20 viral infections) across demographics and TB disease states were used for gene signature discovery and model training and validation.

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Ectotherm body temperatures fluctuate with environmental variability and host behavior, which may influence host-pathogen interactions. Fungal pathogens are a major threat to ectotherms and may be highly responsive to the fluctuating thermal profiles of individual hosts, especially cool-loving fungi exposed to high host temperatures. However, most studies estimate pathogen thermal performance based on averages of host or surrogate environmental temperatures, potentially missing effects of short-term host temperature shifts such as daily or hourly heat spikes.

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Identifying hotspots of biological diversity is a key step in conservation prioritisation. Melanesia-centred on the vast island of New Guinea-is increasingly recognised for its exceptionally species-rich and endemic biota. Here we show that Melanesia has the world's most diverse insular amphibian fauna, with over 7% of recognised global frog species in less than 0.

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Understanding the reliability and relevance of a toxicological assessment is important for gauging the overall confidence and communicating the degree of uncertainty related to it. The process involved in assessing reliability and relevance is well defined for experimental data. Similar criteria need to be established for predictions, as they become increasingly more important to fill data gaps and need to be reasonably integrated as additional lines of evidence.

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Laser Induced Breakdown Spectroscopy (LIBS) in the Ultra Violet/Visible/Near-IR (UVN) spectral range is a powerful analytical tool that facilitates the interpretation of Raman spectroscopic data by providing additional details in elemental chemistry. To acquire the complete information of molecular vibrations for more accurate and precise chemical bonding and structural analysis, an ideal optical sensing facility should be able to rapidly probe the broad vibrational dipole and polarizability responses of molecules by acquiring both Raman scattering and mid-IR emission spectroscopic signatures. Recently, the research team at Brimrose has developed a novel optical technology, Long-Wave IR (LWIR) LIBS.

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Ultra-low velocity zones (ULVZs) are localized small-scale patches with extreme physical properties at the core-mantle boundary that often gather at the margins of Large Low Velocity Provinces (LLVPs). Recent studies have discovered several mega-sized ULVZs with a lateral dimension of ~900 km. However, the detailed structures and physical properties of these ULVZs and their relationship to LLVP edges are not well constrained and their formation mechanisms are poorly understood.

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The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes the disease chytridiomycosis, which is a primary driver for amphibian population declines and extinctions worldwide. For highly susceptible species, such as the green and golden bell frog Litoria aurea, large numbers of Bd-related mortalities are thought to occur during the colder season (winter), when low temperatures favour the growth of the pathogen. However, extant L.

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Mechanistically-driven alternative approaches to hazard assessment invariably require a battery of tests, including both models and experimental data. The decision-making process, from selection of the methods to combining the information based on the weight-of-evidence, is ideally described in published guidelines or protocols. This ensures that the application of such approaches is defendable to reviewers within regulatory agencies and across the industry.

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Raman spectroscopy and laser induced breakdown spectroscopy (LIBS) are complementary techniques that together can provide a comprehensive characterization of geologic environments. For landed missions with constrained access to target materials on other planetary bodies, discerning signatures of life and habitability can be daunting, particularly where the preservation of organic compounds that contain the building blocks of life is limited. The main challenge facing any spectroscopy measurements of natural samples is the complicated spectra that often contain signatures for multiple components, particularly in rocks that are composed of several minerals with surfaces colonized by microbes.

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Anti-PD-L1 antibodies benefit many cancer patients, even those with "non-inflamed tumor". Determining which patients will benefit remains an important clinical goal. In a non-inflamed tumor mouse model, we found that PD-L1 was highly expressed on antigen-presenting cells (APCs) especially on CD103 CD11c dendritic cells in tumor-draining lymph nodes (dLNs), suppressing T-cell priming by APCs.

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Immune checkpoint inhibitors targeting the PD-1/PD-L1 axis lead to durable clinical responses in subsets of cancer patients across multiple indications, including non-small cell lung cancer (NSCLC), urothelial carcinoma (UC) and renal cell carcinoma (RCC). Herein, we complement PD-L1 immunohistochemistry (IHC) and tumor mutation burden (TMB) with RNA-seq in 366 patients to identify unifying and indication-specific molecular profiles that can predict response to checkpoint blockade across these tumor types. Multiple machine learning approaches failed to identify a baseline transcriptional signature highly predictive of response across these indications.

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Article Synopsis
  • Elevated ATP levels in cystic fibrosis (CF) patients may provide health benefits, particularly in fighting advanced solid tumors.
  • Research indicates that intravenous ATP can restore ATP levels in cancer patients, leading to improvements in their health and quality of life.
  • The authors propose that the high ATP levels in CF patients could also enhance their survival rates after contracting COVID-19, and they explore the potential clinical applications of this hypothesis.
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The earliest atmospheres of rocky planets originate from extensive volatile release during magma ocean epochs that occur during assembly of the planet. These establish the initial distribution of the major volatile elements between different chemical reservoirs that subsequently evolve via geological cycles. Current theoretical techniques are limited in exploring the anticipated range of compositional and thermal scenarios of early planetary evolution, even though these are of prime importance to aid astronomical inferences on the environmental context and geological history of extrasolar planets.

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Our purpose was to compare the mechanical properties of the protective outer shells of various athletic helmets in their final, fully manufactured form. Sections were taken from 3 different helmet shells (Bauer RE-AKT hockey helmet, Cascade R lacrosse helmet, and Riddell Speedflex football helmet) at 4 different locations (front, side, top, and rear) for a total of 12 test specimens. The 4 specimens from each helmet shell were potted together in epoxy resin moulds and mechanically polished.

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The assessment of skin sensitization has evolved over the past few years to include in vitro assessments of key events along the adverse outcome pathway and opportunistically capitalize on the strengths of in silico methods to support a weight of evidence assessment without conducting a test in animals. While in silico methods vary greatly in their purpose and format; there is a need to standardize the underlying principles on which such models are developed and to make transparent the implications for the uncertainty in the overall assessment. In this contribution, the relationship between skin sensitization relevant effects, mechanisms, and endpoints are built into a hazard assessment framework.

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Article Synopsis
  • Emerging infectious diseases can significantly reduce wildlife populations, and while some may recover, others do not, making it crucial to understand these recovery differences for better management.
  • A chytridiomycosis outbreak in the late 1980s in Australia led to declines in frog species, with some like Litoria nannotis recovering and others like Litoria dayi failing to do so.
  • Research on L. dayi showed sufficient gene flow and diversity, indicating dispersal and genetic variation aren't the issues; however, ongoing chytridiomycosis impacts its ability to thrive, with evidence of current genetic adaptation to the disease.
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Monitoring mechanical systems operating in uncertain environments contaminated with both environmental disturbances and noise lead directly to low signal-to-noise-ratios, creating an extremely challenging processing problem, especially in real-time. In order to estimate the performance of a particular system from uncertain vibrational data, it is necessary to identify its unique resonant (modal) frequency signature. The monitoring of structural modes to determine the condition of a device under investigation is essential, especially if it is a critical entity of an operational system.

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