252,730 results on '"Knight, A."'
Search Results
2. A Faculty Personal Tutor Model to Support Student Transition into Higher Education during a Global Pandemic
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Rebecca Broadbent and Gillian Knight
- Abstract
In 2020, Science, Technology, Engineering and Math (STEM) faculty within a United Kingdom university implemented an online personal tutoring model. This model aimed to deliver a consistent experience to ~1000 students, supporting learning and fostering a sense of belonging during a global pandemic. Here we describe and evaluate a Curriculum Integrated personal tutor model, designed to provide a structured and dialogic student experience. We provide details on the timetabled activities, aligned to student development needs, and reflect on the model's effectiveness in supporting student learning, building belonging, and providing accessible delivery. We highlight strengths and explore weaknesses, providing recommendations for implementation of this type of model at other institutions.
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- 2024
3. Demonstration of Beyond Terabit/s/lambda Nonlinearity-free Transmission over the Hollow-core Fibre
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Hong, Yang, Almonacil, Sylvain, Mardoyan, Haik, Carrero, Carina Castineiras, Osuna, Sergio, Gomez, Javier R., Knight, David R., and Renaudier, Jeremie
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Electrical Engineering and Systems Science - Signal Processing ,Electrical Engineering and Systems Science - Systems and Control ,Physics - Optics - Abstract
We demonstrate nonlinearity-free transmission of Terabit/s/lambda PCS-64QAM signals through an HCF-based optical recirculating loop, which yields ~17.4% higher capacity than SMF-based loop under 23-dBm launch power (~13.5 dBm/channel) after 25 loops. Both lab experiment and field trial show HCF exhibits ~1.6-us/km lower latency than SMF., Comment: ECOC 2024 - 50th European Conference and Exhibition on Optical Communication Th1B.4 at 09:45am SC05: Optical transmission systems
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- 2024
4. Capture Rates of Highly Degenerate Neutrons
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Knight, B., Caballero, O. L., and Schatz, H.
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Nuclear Theory ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
At the low temperature and high density conditions of a neutron star crust neutrons are degenerate. In this work, we study the effect of this degeneracy on the capture rates of neutrons on neutron rich nuclei in accreted crusts. We use a statistical Hauser-Feshbach model to calculate neutron capture rates and find that neutron degeneracy can increase rates significantly. Changes increase from a factor of a few to many orders of magnitude near the neutron drip line. We also quantify uncertainties due to model inputs for masses, $\gamma$-strength functions, and level densities. We find that uncertainties increase dramatically away from stability and that degeneracy tends to increase these uncertainties further, except for cases near the neutron drip line where degeneracy leads to more robustness. As in the case of capture of classically distributed neutrons, variations in the mass model have the strongest impact. Corresponding variations in the reaction rates can be as high as 3 to 4 orders of magnitude, and be more than 5 times larger than under classical conditions. To ease the incorporation of neutron degeneracy in nucleosynthesis networks, we provide tabulated results of capture rates as well as analytical expressions as function of temperature and neutron chemical potential, for proton numbers between $3 \le Z \le 85$, derived from fits to our numerical results. Fits are based on a new parametrization that complements previously employed power law approximations with additional Lorentzian terms that account for low energy resonances, significantly improving accuracy., Comment: 16 pages, 11 figures. Tabulated reaction rates can be found at https://github.com/Nyrb1001/Degenerate-Neutron-Captures
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- 2024
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5. EFT Workshop at Notre Dame
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Smith, Nick, Spitzbart, Daniel, Dickinson, Jennet, Wilson, Jon, Gray, Lindsey, Mohrman, Kelci, Bhattacharya, Saptaparna, Piccinelli, Andrea, Roy, Titas, Paspalaki, Garyfallia, Fontes, Duarte, Martin, Adam, Shepherd, William, Cruz, Sergio Sánchez, Goncalves, Dorival, Gritsan, Andrei, Prosper, Harrison, Junk, Tom, Cranmer, Kyle, Peskin, Michael, Gilbert, Andrew, Langford, Jonathon, Petriello, Frank, Mantani, Luca, Wightman, Andrew, Knight, Charlotte, Shyamsundar, Prasanth, Basnet, Aashwin, Boldrini, Giacomo, and Lannon, Kevin
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High Energy Physics - Experiment - Abstract
The LPC EFT workshop was held April 25-26, 2024 at the University of Notre Dame. The workshop was organized into five thematic sessions: "how far beyond linear" discusses issues of truncation and validity in interpretation of results with an eye towards practicality; "reconstruction-level results" visits the question of how best to design analyses directly targeting inference of EFT parameters; "logistics of combining likelihoods" addresses the challenges of bringing a diverse array of measurements into a cohesive whole; "unfolded results" tackles the question of designing fiducial measurements for later use in EFT interpretations, and the benefits and limitations of unfolding; and "building a sample library" addresses how best to generate simulation samples for use in data analysis. This document serves as a summary of presentations, subsequent discussions, and actionable items identified over the course of the workshop.
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- 2024
6. Identifying influential node groups in networks with core-periphery structure
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Bae, Gyuho, Knight, Philip A., and Eom, Young-Ho
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Physics - Physics and Society ,Physics - Data Analysis, Statistics and Probability - Abstract
Identifying influential spreaders is a crucial problem for practical applications in network science. The core-periphery(C-P) structure, common in many real-world networks, comprises a densely interconnected group of nodes(core) and the rest of the sparsely connected nodes subordinated to the core(periphery). Core nodes are expected to be more influential than periphery nodes generally, but recent studies suggest that this is not the case in some networks. In this work, we look for mesostructural conditions that arise when core nodes are significantly more influential than periphery nodes. In particular, we investigate the roles of the internal and external connectivity of cores in their relative influence. We observe that the internal and external connectivity of cores are broadly distributed, and the relative influence of the cores is also broadly distributed in real-world networks. Our key finding is that the internal connectivity of cores is positively correlated with their relative influence, whereas the relative influence increases up to a certain value of the external connectivity and decreases thereafter. Finally, results from the model-generated networks clarify the observations from the real-world networks. Our findings provide a structural condition for influential cores in networks and shed light on why some cores are influential and others are not.
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- 2024
7. Domain Shift Analysis in Chest Radiographs Classification in a Veterans Healthcare Administration Population
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Chandrashekar, Mayanka, Goethert, Ian, Haque, Md Inzamam Ul, McMahon, Benjamin, Dhaubhadel, Sayera, Knight, Kathryn, Erdos, Joseph, Reagan, Donna, Taylor, Caroline, Kuzmak, Peter, Gaziano, John Michael, McAllister, Eileen, Costa, Lauren, Ho, Yuk-Lam, Cho, Kelly, Tamang, Suzanne, Fodeh-Jarad, Samah, Ovchinnikova, Olga S., Justice, Amy C., Hinkle, Jacob, and Danciu, Ioana
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Electrical Engineering and Systems Science - Image and Video Processing ,Computer Science - Artificial Intelligence ,Computer Science - Computer Vision and Pattern Recognition - Abstract
Objectives: This study aims to assess the impact of domain shift on chest X-ray classification accuracy and to analyze the influence of ground truth label quality and demographic factors such as age group, sex, and study year. Materials and Methods: We used a DenseNet121 model pretrained MIMIC-CXR dataset for deep learning-based multilabel classification using ground truth labels from radiology reports extracted using the CheXpert and CheXbert Labeler. We compared the performance of the 14 chest X-ray labels on the MIMIC-CXR and Veterans Healthcare Administration chest X-ray dataset (VA-CXR). The VA-CXR dataset comprises over 259k chest X-ray images spanning between the years 2010 and 2022. Results: The validation of ground truth and the assessment of multi-label classification performance across various NLP extraction tools revealed that the VA-CXR dataset exhibited lower disagreement rates than the MIMIC-CXR datasets. Additionally, there were notable differences in AUC scores between models utilizing CheXpert and CheXbert. When evaluating multi-label classification performance across different datasets, minimal domain shift was observed in unseen datasets, except for the label "Enlarged Cardiomediastinum." The study year's subgroup analyses exhibited the most significant variations in multi-label classification model performance. These findings underscore the importance of considering domain shifts in chest X-ray classification tasks, particularly concerning study years. Conclusion: Our study reveals the significant impact of domain shift and demographic factors on chest X-ray classification, emphasizing the need for improved transfer learning and equitable model development. Addressing these challenges is crucial for advancing medical imaging and enhancing patient care.
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- 2024
8. The GLEAMing of the first supermassive black holes: III. Radio sources with ultra-faint host galaxies
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Broderick, J. W., Seymour, N., Drouart, G., Knight, D., Afonso, J. M., De Breuck, C., Galvin, T. J., Hedge, A. J., Lehnert, M. D., Noirot, G., Shabala, S. S., Turner, R. J., and Vernet, J.
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Astrophysics - Astrophysics of Galaxies - Abstract
We present deep near-infrared $K_{\rm s}$-band imaging for 35 of the 53 sources from the high-redshift ($z > 2$) radio galaxy candidate sample defined in Broderick et al. (2022). These images were obtained using the High-Acuity Widefield $K$-band Imager (HAWK-I) on the Very Large Telescope. Host galaxies are detected for 27 of the sources, with $K_{\rm s} \approx 21.6$$-$$23.0$ mag (2$''$ diameter apertures; AB). The remaining eight targets are not detected to a median $3\sigma$ depth of $K_{\rm s} \approx 23.3$ mag ($2''$ diameter apertures). We examine the radio and near-infrared flux densities of the 35 sources, comparing them to the known $z > 3$ powerful radio galaxies with 500-MHz radio luminosities $L_{500\,{\rm MHz}} > 10^{27}$ W Hz$^{-1}$. By plotting 150-MHz flux density versus $K_{\rm s}$-band flux density, we find that, similar to the sources from the literature, these new targets have large radio to near-infrared flux density ratios, but extending the distribution to fainter flux densities. Five of the eight HAWK-I deep non-detections have a median $3\sigma$ lower limit of $K_{\rm s} \gtrsim 23.8$ mag ($1.5''$ diameter apertures); these five targets, along with a further source from Broderick et al. (2022) with a deep non-detection ($K_{\rm s} \gtrsim 23.7$ mag; $3\sigma$; $2''$ diameter aperture) in the Southern H-ATLAS Regions $K_{\rm s}$-band Survey, are considered candidates to be ultra-high-redshift ($z > 5$) radio galaxies. The extreme radio to near-infrared flux density ratios ($>10^5$) for these six sources are comparable to TN J0924$-$2201, GLEAM J0856$+$0223 and TGSS J1530$+$1049, the three known powerful radio galaxies at $z > 5$. For a selection of galaxy templates with different stellar masses, we show that $z \gtrsim 4.2$ is a plausible scenario for our ultra-high-redshift candidates if the stellar mass $M_{\rm *} \gtrsim 10^{10.5}\,{\rm M}_\odot$. [abridged], Comment: 24 pages, 5 figures (one of which is a multi-page figure with 30 separate panels), 2 tables, accepted for publication in PASA
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- 2024
9. Optical absorption spectrum reveals gaseous chlorine in anti-resonant hollow core fibres
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Harrington, Kerrianne, Mears, Robbie, Stone, James M., Wadsworth, William J., Knight, Jonathan C., and Birks, T. A.
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Physics - Optics - Abstract
We have observed unexpected spectral attenuation of ultraviolet light in freshly drawn hollow core optical fibres. When the fibre ends are left open to atmosphere, this loss feature dissipates over time. The loss matches the absorption spectrum of gaseous (molecular) chlorine and, given enough time, the transmission spectrum of the fibre recovers to that expected from the morphological structure of the fibre. Our measurements indicate an initial chlorine concentration of 0.45 $\mu$ mol/cm$^{3}$ in the hollow core, equivalent to 1.1 mol% Cl$_{2}$ at atmospheric pressure.
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- 2024
10. Spatio-temporal Structure of Excitation and Inhibition Emerges in Spiking Neural Networks with and without Biologically Plausible Constraints
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Mészáros, Balázs, Knight, James, and Nowotny, Thomas
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Computer Science - Neural and Evolutionary Computing - Abstract
We present a Spiking Neural Network (SNN) model that incorporates learnable synaptic delays using Dilated Convolution with Learnable Spacings (DCLS). We train this model on the Raw Heidelberg Digits keyword spotting benchmark using Backpropagation Through Time with surrogate gradients. Analysing the spatio-temporal structure of synaptic interactions in the network we observe that after training excitation and inhibition are grouped together both in space and time. To further enhance the efficiency and biological realism of our model, we implemented a dynamic pruning strategy that combines DEEP R for connection removal and RigL for connection reintroduction, ensuring that the network maintains optimal connectivity throughout training. Additionally, we incorporated Dale's Principle, enforcing each neuron to be exclusively excitatory or inhibitory -- aligning our model closer to biological neural networks. We observed that, after training, the spatio-temporal patterns of excitation and inhibition appeared in the more biologically plausible model as well. Our research demonstrates the potential of integrating learnable delays, dynamic pruning, and biological constraints to develop efficient SNN models for temporal data processing. Furthermore, our results enhance the understanding of spatio-temporal dynamics in SNNs -- suggesting that the spatio-temporal features which emerge from training are robust to both pruning and rewiring processes -- providing a solid foundation for future work in neuromorphic computing applications., Comment: 10 pages, 4 figures, submitted to Frontiers in Computational Neuroscience
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- 2024
11. A Review of AI and Machine Learning Contribution in Predictive Business Process Management (Process Enhancement and Process Improvement Approaches)
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Abbasi, Mostafa, Nishat, Rahnuma Islam, Bond, Corey, Graham-Knight, John Brandon, Lasserre, Patricia, Lucet, Yves, and Najjaran, Homayoun
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Computer Science - Artificial Intelligence ,Computer Science - Machine Learning - Abstract
Purpose- The significance of business processes has fostered a close collaboration between academia and industry. Moreover, the business landscape has witnessed continuous transformation, closely intertwined with technological advancements. Our main goal is to offer researchers and process analysts insights into the latest developments concerning Artificial Intelligence (AI) and Machine Learning (ML) to optimize their processes in an organization and identify research gaps and future directions in the field. Design/methodology/approach- In this study, we perform a systematic review of academic literature to investigate the integration of AI/ML in business process management (BPM). We categorize the literature according to the BPM life-cycle and employ bibliometric and objective-oriented methodology, to analyze related papers. Findings- In business process management and process map, AI/ML has made significant improvements using operational data on process metrics. These developments involve two distinct stages: (1) process enhancement, which emphasizes analyzing process information and adding descriptions to process models, and (2) process improvement, which focuses on redesigning processes based on insights derived from analysis. Research limitations/implications- While this review paper serves to provide an overview of different approaches for addressing process-related challenges, it does not delve deeply into the intricacies of fine-grained technical details of each method. This work focuses on recent papers conducted between 2010 and 2024. Originality/value- This paper adopts a pioneering approach by conducting an extensive examination of the integration of AI/ML techniques across the entire process management lifecycle. Additionally, it presents groundbreaking research and introduces AI/ML-enabled integrated tools, further enhancing the insights for future research.
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- 2024
12. Career Paths of Doctoral Recipients in Engineering and Computer Science: Trends by Sex, Race, Citizenship, and Discipline with an Emphasis on Biomedical Engineering
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Maya Denton, David B. Knight, Jessica R. Deters, Dustin M. Grote, and Maura Borrego
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We summarize national-scale data for Ph.D. earners in engineering or computer science from 2015 to 2019 whose post-graduate school employment is known, highlighting outcomes for biological/biomedical/biosystems engineering students. We use NSF's Survey of Earned Doctorates (SED), which has collected information from Ph.D. recipients in the USA since 1957. The data are collected at the time of degree completion and constitute a greater than 90% response rate. Compared to all engineering and computer science disciplines, biological/biomedical/biosystems engineering has a higher proportion going to 4yr/med/research institutions (52% vs. 33%) and non-profit (3.6% vs. 2.9%) and lower proportion going to industry (33% vs. 48%), government (4.3% vs. 8.4%), and is similar for non-US positions (6.1% vs. 5.7%). Compared to 2010--2014 biological/biomedical/biosystems engineering Ph.D. recipients, more 2015--2019 recipients are going to industry (25% to 33%) and fewer to 4yr/med/research institutions (59% to 52%) and government (5.3% to 4.3%). Across all engineering and computer science disciplines, a smaller proportion of females entered industry (43%) compared to males (49%), while a larger proportion of females entered 4yr/med/research institutions (37%) compared to males (32%). Over half of Asian doctoral recipients entered industry, as compared to 38% of Hispanic doctoral recipients. In contrast, a higher proportion of Hispanic individuals (37%) entered 4yr/med/research institutions after their doctoral programs, as compared to 31% of Asian doctoral recipients. Black doctoral recipients had the highest proportion enter positions in government (14%) and non-profit (4%) sectors. Our results are situated in the broader literature focused on postdoctoral career, training, and employment sectors and trends in STEM. We discuss implications for graduate programs, policymakers, and researchers.
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- 2024
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13. PhD Student Funding Patterns: Placing Biomedical, Biological, and Biosystems Engineering in the Context of Engineering Sub-Disciplines, Biological Sciences, and Other STEM Disciplines
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David B. Knight, Dustin M. Grote, Timothy J. Kinoshita, and Maura Borrego
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Whether doctoral students are funded primarily by fellowships, research assistantships, or teaching assistantships impacts their degree completion, time to degree, learning outcomes, and short- and long-term career outcomes. Variations in funding patterns have been studied at the broad field level but not comparing engineering sub-disciplines. We addressed two research questions: How do PhD student funding mechanisms vary across engineering sub-disciplines? And how does variation in funding mechanisms across engineering sub-disciplines map onto the larger STEM disciplinary landscape? We analyzed 103,373 engineering and computing responses to the U.S. Survey of Earned Doctorates collected between 2007 and 2016. We conducted analysis of variance with Bonferroni post hoc comparisons to examine variation in funding across sub-disciplines. Then, we conducted a k-means cluster analysis on percentage variables for fellowship, research, and teaching assistantship funding mechanism with STEM sub-discipline as the unit of analysis. A statistically significantly greater percentage of biomedical/biological engineering doctoral students were funded via a fellowship, compared to every other engineering sub-discipline. Consequently, biomedical/biological engineering had significantly lower proportions of students supported via research and teaching assistantships than nearly all other engineering sub-disciplines. We identified five clusters. The majority of engineering sub-disciplines grouped together into a cluster with high research assistantships and low teaching assistantships. Biomedical/biological engineering clustered in the high fellowships grouping with most other biological sciences but no other engineering sub-disciplines. Biomedical/biological engineering behaves much more like biological and life sciences in utilizing fellowships to fund graduate students, far more than other engineering sub-disciplines. Our study provides further evidence of the prevalence of fellowships in life sciences and how it stretches into biomedical/biological engineering. The majority of engineering sub-disciplines relied more on research assistantships to fund graduate study. The lack of uniformity provides an opportunity to diversify student experiences during their graduate programs but also necessitates an awareness to the advantages and disadvantages that different funding portfolios can bestow on students.
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- 2024
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14. Quantifying the Risk in Dynamic Thermal Line Rating
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Dawson, L., Karimi, S., and Knight, A.M.
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- 2022
15. Early biological markers of post-acute sequelae of SARS-CoV-2 infection.
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Lu, Scott, Peluso, Michael, Glidden, David, Davidson, Michelle, Lugtu, Kara, Pineda-Ramirez, Jesus, Tassetto, Michel, Garcia-Knight, Miguel, Zhang, Amethyst, Goldberg, Sarah, Chen, Jessica, Fortes-Cobby, Maya, Park, Sara, Martinez, Ana, So, Matthew, Donovan, Aidan, Viswanathan, Badri, Hoh, Rebecca, Donohue, Kevin, McIlwain, David, Gaudiliere, Brice, Anglin, Khamal, Yee, Brandon, Chenna, Ahmed, Winslow, John, Petropoulos, Christos, Deeks, Steven, Briggs-Hagen, Melissa, Andino, Raul, Midgley, Claire, Martin, Jeffrey, Saydah, Sharon, and Kelly, John
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Humans ,COVID-19 ,SARS-CoV-2 ,Male ,Female ,Adult ,Viral Load ,Biomarkers ,RNA ,Viral ,Middle Aged ,Post-Acute COVID-19 Syndrome ,Aged ,Cytokines ,Antibodies ,Viral ,Immunoglobulin G - Abstract
To understand the roles of acute-phase viral dynamics and host immune responses in post-acute sequelae of SARS-CoV-2 infection (PASC), we enrolled 136 participants within 5 days of their first positive SARS-CoV-2 real-time PCR test. Participants self-collected up to 21 nasal specimens within the first 28 days post-symptom onset; interviewer-administered questionnaires and blood samples were collected at enrollment, days 9, 14, 21, 28, and month 4 and 8 post-symptom onset. Defining PASC as the presence of any COVID-associated symptom at their 4-month visit, we compared viral markers (quantity and duration of nasal viral RNA load, infectious viral load, and plasma N-antigen level) and host immune markers (IL-6, IL-10, TNF-α, IFN-α, IFN-γ, MCP, IP-10, and Spike IgG) over the acute period. Compared to those who fully recovered, those reporting PASC demonstrated significantly higher maximum levels of SARS-CoV-2 RNA and N-antigen, burden of RNA and infectious viral shedding, and lower Spike-specific IgG levels within 9 days post-illness onset. No significant differences were identified among a panel of host immune markers. Our results suggest early viral dynamics and the associated host immune responses play a role in the pathogenesis of PASC, highlighting the importance of understanding early biological markers in the natural history of PASC.
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- 2024
16. Impact of diet change on the gut microbiome of common marmosets (Callithrix jacchus).
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Tang-Wing, Cassandra, Mohanty, Ipsita, Bryant, MacKenzie, Makowski, Katherine, Melendez, Daira, Dorrestein, Pieter, Knight, Rob, Caraballo-Rodríguez, Andrés, Allaband, Celeste, and Jenné, Keith
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marmoset ,metabolome ,metagenomics ,microbiome ,nonhuman microbiome ,nonhuman microbiota ,nutrition ,physiology ,primate ,veterinary microbiology ,Animals ,Callithrix ,Gastrointestinal Microbiome ,Diet ,Male ,Female ,Feces ,Bifidobacterium - Abstract
UNLABELLED: Gastrointestinal diseases are the most frequently reported clinical problems in captive common marmosets (Callithrix jacchus), often affecting the health and welfare of the animal and ultimately their use as a research subject. The microbiome has been shown to be intimately connected to diet and gastrointestinal health. Here, we use shotgun metagenomics and untargeted metabolomics in fecal samples of common marmosets collected before, during, and after a dietary transition from a biscuit to a gel diet. The overall health of marmosets, measured as weight recovery and reproductive outcome, improved after the diet transition. Moreover, each marmoset pair had significant shifts in the microbiome and metabolome after the diet transition. In general, we saw a decrease in Escherichia coli and Prevotella species and an increase in Bifidobacterium species. Untargeted metabolic profiles indicated that polyamine levels, specifically cadaverine and putrescine, were high after diet transition, suggesting either an increase in excretion or a decrease in intestinal reabsorption at the intestinal level. In conclusion, our data suggest that Bifidobacterium species could potentially be useful as probiotic supplements to the laboratory marmoset diet. Future studies with a larger sample size will be beneficial to show that this is consistent with the diet change. IMPORTANCE: Appropriate diet and health of the common marmoset in captivity are essential both for the welfare of the animal and to improve experimental outcomes. Our study shows that a gel diet compared to a biscuit diet improves the health of a marmoset colony, is linked to increases in Bifidobacterium species, and increases the removal of molecules associated with disease. The diet transition had an influence on the molecular changes at both the pair and time point group levels, but only at the pair level for the microbial changes. It appears to be more important which genes and functions present changed rather than specific microbes. Further studies are needed to identify specific components that should be considered when choosing an appropriate diet and additional supplementary foods, as well as to validate the benefits of providing probiotics. Probiotics containing Bifidobacterium species appear to be useful as probiotic supplements to the laboratory marmoset diet, but additional work is needed to validate these findings.
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- 2024
17. Associations between gut microbiota and incident fractures in the FINRISK cohort.
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Grahnemo, Louise, Kambur, Oleg, Lahti, Leo, Jousilahti, Pekka, Niiranen, Teemu, Knight, Rob, Salomaa, Veikko, Havulinna, Aki, and Ohlsson, Claes
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Gastrointestinal Microbiome ,Humans ,Male ,Female ,Fractures ,Bone ,Middle Aged ,Finland ,Aged ,Bacteria ,Metagenome ,Cohort Studies ,Incidence ,Metagenomics ,Proteobacteria ,Risk Factors ,Adult - Abstract
The gut microbiota (GM) can regulate bone mass, but its association with incident fractures is unknown. We used Cox regression models to determine whether the GM composition is associated with incident fractures in the large FINRISK 2002 cohort (n = 7043, 1092 incident fracture cases, median follow-up time 18 years) with information on GM composition and functionality from shotgun metagenome sequencing. Higher alpha diversity was associated with decreased fracture risk (hazard ratio [HR] 0.92 per standard deviation increase in Shannon index, 95% confidence interval 0.87-0.96). For beta diversity, the first principal component was associated with fracture risk (Aitchison distance, HR 0.90, 0.85-0.96). In predefined phyla analyses, we observed that the relative abundance of Proteobacteria was associated with increased fracture risk (HR 1.14, 1.07-1.20), while the relative abundance of Tenericutes was associated with decreased fracture risk (HR 0.90, 0.85-0.96). Explorative sub-analyses within the Proteobacteria phylum showed that higher relative abundance of Gammaproteobacteria was associated with increased fracture risk. Functionality analyses showed that pathways related to amino acid metabolism and lipopolysaccharide biosynthesis associated with fracture risk. The relative abundance of Proteobacteria correlated with pathways for amino acid metabolism, while the relative abundance of Tenericutes correlated with pathways for butyrate synthesis. In conclusion, the overall GM composition was associated with incident fractures. The relative abundance of Proteobacteria, especially Gammaproteobacteria, was associated with increased fracture risk, while the relative abundance of Tenericutes was associated with decreased fracture risk. Functionality analyses demonstrated that pathways known to regulate bone health may underlie these associations.
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- 2024
18. Pangenome comparison of Bacteroides fragilis genomospecies unveils genetic diversity and ecological insights
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Oles, Renee E, Terrazas, Marvic Carrillo, Loomis, Luke R, Hsu, Chia-Yun, Tribelhorn, Caitlin, Belda-Ferre, Pedro, C., Allison, Bryant, MacKenzie, Young, Jocelyn A, Carrow, Hannah C, Sandborn, William J, Dulai, Parambir S, Sivagnanam, Mamata, Pride, David, Knight, Rob, and Chu, Hiutung
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Microbiology ,Biological Sciences ,Biomedical and Clinical Sciences ,Microbiome ,Genetics ,Emerging Infectious Diseases ,Digestive Diseases ,Infectious Diseases ,2.2 Factors relating to the physical environment ,2.1 Biological and endogenous factors ,Infection ,Bacteroides fragilis ,Humans ,Genome ,Bacterial ,Genetic Variation ,Gastrointestinal Microbiome ,Phylogeny ,Bacteroides Infections ,Whole Genome Sequencing ,Drug Resistance ,Bacterial ,pangenome ,commensal bacteria ,genomic diversity ,niche adaptation ,Bacteroides - Abstract
Bacteroides fragilis is a Gram-negative commensal bacterium commonly found in the human colon, which differentiates into two genomospecies termed divisions I and II. Through a comprehensive collection of 694 B. fragilis whole genome sequences, we identify novel features distinguishing these divisions. Our study reveals a distinct geographic distribution with division I strains predominantly found in North America and division II strains in Asia. Additionally, division II strains are more frequently associated with bloodstream infections, suggesting a distinct pathogenic potential. We report differences between the two divisions in gene abundance related to metabolism, virulence, stress response, and colonization strategies. Notably, division II strains harbor more antimicrobial resistance (AMR) genes than division I strains. These findings offer new insights into the functional roles of division I and II strains, indicating specialized niches within the intestine and potential pathogenic roles in extraintestinal sites.ImportanceUnderstanding the distinct functions of microbial species in the gut microbiome is crucial for deciphering their impact on human health. Classifying division II strains as Bacteroides fragilis can lead to erroneous associations, as researchers may mistakenly attribute characteristics observed in division II strains to the more extensively studied division I B. fragilis. Our findings underscore the necessity of recognizing these divisions as separate species with distinct functions. We unveil new findings of differential gene prevalence between division I and II strains in genes associated with intestinal colonization and survival strategies, potentially influencing their role as gut commensals and their pathogenicity in extraintestinal sites. Despite the significant niche overlap and colonization patterns between these groups, our study highlights the complex dynamics that govern strain distribution and behavior, emphasizing the need for a nuanced understanding of these microorganisms.
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- 2024
19. House dust metagenome and pulmonary function in a US farming population.
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Lee, Mikyeong, Kaul, Abhishek, Ward, James, Zhu, Qiyun, Richards, Marie, Wang, Ziyue, González, Antonio, Parks, Christine, Beane Freeman, Laura, Umbach, David, Motsinger-Reif, Alison, Knight, Rob, and London, Stephanie
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Metagenome ,Microbiome ,Microbiota ,Respiratory function tests ,Spirometry ,Whole genome sequencing ,Dust ,Humans ,Metagenome ,Female ,Male ,United States ,Microbiota ,Middle Aged ,Lung ,Adult ,Bacteria ,Forced Expiratory Volume ,Agriculture ,Respiratory Function Tests ,Vital Capacity ,Metagenomics - Abstract
BACKGROUND: Chronic exposure to microorganisms inside homes can impact respiratory health. Few studies have used advanced sequencing methods to examine adult respiratory outcomes, especially continuous measures. We aimed to identify metagenomic profiles in house dust related to the quantitative traits of pulmonary function and airway inflammation in adults. Microbial communities, 1264 species (389 genera), in vacuumed bedroom dust from 779 homes in a US cohort were characterized by whole metagenome shotgun sequencing. We examined two overall microbial diversity measures: richness (the number of individual microbial species) and Shannon index (reflecting both richness and relative abundance). To identify specific differentially abundant genera, we applied the Lasso estimator with high-dimensional inference methods, a novel framework for analyzing microbiome data in relation to continuous traits after accounting for all taxa examined together. RESULTS: Pulmonary function measures (forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio) were not associated with overall dust microbial diversity. However, many individual microbial genera were differentially abundant (p-value < 0.05 controlling for all other microbial taxa examined) in relation to FEV1, FVC, or FEV1/FVC. Similarly, fractional exhaled nitric oxide (FeNO), a marker of airway inflammation, was unrelated to overall microbial diversity but associated with differential abundance for many individual genera. Several genera, including Limosilactobacillus, were associated with a pulmonary function measure and FeNO, while others, including Moraxella to FEV1/FVC and Stenotrophomonas to FeNO, were associated with a single trait. CONCLUSIONS: Using state-of-the-art metagenomic sequencing, we identified specific microorganisms in indoor dust related to pulmonary function and airway inflammation. Some were previously associated with respiratory conditions; others were novel, suggesting specific environmental microbial components contribute to various respiratory outcomes. The methods used are applicable to studying microbiome in relation to other continuous outcomes. Video Abstract.
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- 2024
20. The Impact of Intimate Partner Violence on Homelessness and Returns to Housing: A Qualitative Analysis From the California Statewide Study of People Experiencing Homelessness.
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Hargrave, Anita S, Knight, Kelly R, Dhatt, Zena K, Taylor, Grace, Martinez, Dez, and Kushel, Margot
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Social Work ,Criminology ,Human Society ,Homelessness ,Women's Health ,Violence Research ,Violence Against Women ,Behavioral and Social Science ,Mental Health ,Social Determinants of Health ,Peace ,Justice and Strong Institutions ,Gender Equality ,domestic violence ,anything related to domestic violence ,intervention/treatment ,domestic violence and cultural contexts ,Psychology ,Social work ,Clinical and health psychology - Abstract
Homelessness is a public health concern in California and throughout the United States. Intimate partner violence (IPV) is a risk factor for experiencing homelessness. Few studies have examined the interplay between IPV, homelessness, and housing. Qualitative methods can provide a greater understanding of the lived experience of IPV and homelessness to identify potential solutions. We purposefully sampled 104 adults who reported experiencing IPV in the California Statewide Study of People Experiencing Homelessness (CASPEH), a representative, mixed-methods study. We administered semi-structured interviews focusing on IPV and six other topic areas pertaining to homelessness from October 2021 to May 2022. We created and applied a codebook with a multidisciplinary team using a hybrid of deductive and inductive logic. Our analysis included all participants who discussed IPV and homelessness across the seven studies. We conducted a thematic analysis using an interpretivist approach and informed by grounded theory. We found that violence within a partnership was multidimensional (physical, sexual, emotional, and financial) and bidirectional. We identified six themes: (1) IPV precipitated and prolonged homelessness; (2) Need for housing, financial stability, and material resources influenced staying in abusive relationships; (3) Alcohol and illicit substance use exacerbated violence between partners; (4) Participants struggled to find resources in domestic violence (DV) shelters; (5) The healthcare system did not provide substantial support; and (6) discrimination and stigma influenced equitable access to housing and DV resources. Experiencing IPV contributed to homelessness and impeded returns to housing. Limitations in current IPV resources impede care. We propose equitable expansion of survivor-centered services that improve access to long-term subsidized housing, prevent IPV and homelessness with flexible funding options, and facilitate rapid exits from homelessness through trauma-informed, non-congregate shelter that transitions to permanent housing.
- Published
- 2024
21. Trends in volumes and survival after hematopoietic cell transplantation in racial/ethnic minorities.
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Khera, Nandita, Ailawadhi, Sikander, Brazauskas, Ruta, Patel, Jinalben, Jacobs, Benjamin, Ustun, Celalettin, Ballen, Karen, Abid, Muhammad, Diaz Perez, Miguel, Al-Homsi, A, Hashem, Hasan, Hong, Sanghee, Munker, Reinhold, Schears, Raquel, Lazarus, Hillard, Ciurea, Stefan, Badawy, Sherif, Savani, Bipin, Wirk, Baldeep, LeMaistre, C, Bhatt, Neel, Beitinjaneh, Amer, Aljurf, Mahmoud, Sharma, Akshay, Cerny, Jan, Knight, Jennifer, Kelkar, Amar, Yared, Jean, Kindwall-Keller, Tamila, Winestone, Lena, Steinberg, Amir, Arnold, Staci, Seo, Sachiko, Preussler, Jaime, Hossain, Nasheed, Fingrut, Warren, Agrawal, Vaibhav, Hashmi, Shahrukh, Lehmann, Leslie, Wood, William, Rangarajan, Hemalatha, Saber, Wael, and Hahn, Theresa
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Humans ,Hematopoietic Stem Cell Transplantation ,Male ,Female ,Adult ,Middle Aged ,Ethnic and Racial Minorities ,Adolescent ,Child ,Aged ,Young Adult ,Child ,Preschool - Abstract
There has been an increase in volume as well as an improvement in overall survival (OS) after hematopoietic cell transplantation (HCT) for hematologic disorders. It is unknown if these changes have affected racial/ethnic minorities equally. In this observational study from the Center for International Blood and Marrow Transplant Research of 79 904 autologous (auto) and 65 662 allogeneic (allo) HCTs, we examined the volume and rates of change of autoHCT and alloHCT over time and trends in OS in 4 racial/ethnic groups: non-Hispanic Whites (NHWs), non-Hispanic African Americans (NHAAs), and Hispanics across 5 2-year cohorts from 2009 to 2018. Rates of change were compared using Poisson model. Adjusted and unadjusted Cox proportional hazards models examined trends in mortality in the 4 racial/ethnic groups over 5 study time periods. The rates of increase in volume were significantly higher for Hispanics and NHAAs vs NHW for both autoHCT and alloHCT. Adjusted overall mortality after autoHCT was comparable across all racial/ethnic groups. NHAA adults (hazard ratio [HR] 1.13; 95% confidence interval [CI] 1.04-1.22; P = .004) and pediatric patients (HR 1.62; 95% CI 1.3-2.03; P < .001) had a higher risk of mortality after alloHCT than NHWs. Improvement in OS over time was seen in all 4 groups after both autoHCT and alloHCT. Our study shows the rate of change for the use of autoHCT and alloHCT is higher in NHAAs and Hispanics than in NHWs. Survival after autoHCT and alloHCT improved over time; however, NHAAs have worse OS after alloHCT, which has persisted. Continued efforts are needed to mitigate disparities for patients requiring alloHCT.
- Published
- 2024
22. Time of sample collection is critical for the replicability of microbiome analyses
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Allaband, Celeste, Lingaraju, Amulya, Flores Ramos, Stephany, Kumar, Tanya, Javaheri, Haniyeh, Tiu, Maria D, Dantas Machado, Ana Carolina, Richter, R Alexander, Elijah, Emmanuel, Haddad, Gabriel G, Leone, Vanessa A, Dorrestein, Pieter C, Knight, Rob, and Zarrinpar, Amir
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Medical Biochemistry and Metabolomics ,Medical Physiology ,Biomedical and Clinical Sciences ,Nutrition and Dietetics ,Microbiome ,Genetics ,Animals ,Mice ,Microbiota ,Male ,Specimen Handling ,RNA ,Ribosomal ,16S ,Time Factors ,Reproducibility of Results ,Circadian Rhythm ,Retrospective Studies ,Medical biochemistry and metabolomics ,Medical physiology ,Nutrition and dietetics - Abstract
As the microbiome field moves from descriptive and associative research to mechanistic and interventional studies, being able to account for all confounding variables in the experimental design, which includes the maternal effect1, cage effect2, facility differences3, as well as laboratory and sample handling protocols4, is critical for interpretability of results. Despite significant procedural and bioinformatic improvements, unexplained variability and lack of replicability still occur. One underexplored factor is that the microbiome is dynamic and exhibits diurnal oscillations that can change microbiome composition5-7. In this retrospective analysis of 16S amplicon sequencing studies in male mice, we show that sample collection time affects the conclusions drawn from microbiome studies and its effect size is larger than those of a daily experimental intervention or dietary changes. The timing of divergence of the microbiome composition between experimental and control groups is unique to each experiment. Sample collection times as short as only 4 hours apart can lead to vastly different conclusions. Lack of consistency in the time of sample collection may explain poor cross-study replicability in microbiome research. The impact of diurnal rhythms on the outcomes and study design of other fields is unknown but likely significant.
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- 2024
23. Integrating clinical research into electronic health record workflows to support a learning health system.
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Goldhaber, Nicole, Jacobs, Marni, Laurent, Louise, Knight, Rob, Zhu, Wenhong, Pham, Dean, Tran, Allen, Patel, Sandip, Hogarth, Michael, and Longhurst, Christopher
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COVID-19 antibodies ,EHR-integration ,clinical informatics ,clinical research ,interoperability - Abstract
OBJECTIVE: Integrating clinical research into routine clinical care workflows within electronic health record systems (EHRs) can be challenging, expensive, and labor-intensive. This case study presents a large-scale clinical research project conducted entirely within a commercial EHR during the COVID-19 pandemic. CASE REPORT: The UCSD and UCSDH COVID-19 NeutraliZing Antibody Project (ZAP) aimed to evaluate antibody levels to SARS-CoV-2 virus in a large population at an academic medical center and examine the association between antibody levels and subsequent infection diagnosis. RESULTS: The project rapidly and successfully enrolled and consented over 2000 participants, integrating the research trial with standing COVID-19 testing operations, staff, lab, and mobile applications. EHR-integration increased enrollment, ease of scheduling, survey distribution, and return of research results at a low cost by utilizing existing resources. CONCLUSION: The case study highlights the potential benefits of EHR-integrated clinical research, expanding their reach across multiple health systems and facilitating rapid learning during a global health crisis.
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- 2024
24. LHC EFT WG Note: SMEFT predictions, event reweighting, and simulation
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Belvedere, Alberto, Bhattacharya, Saptaparna, Boldrini, Giacomo, Chatterjee, Suman, Calandri, Alessandro, Cruz, Sergio Sánchez, Dickinson, Jennet, Glessgen, Franz J., Goldouzian, Reza, Grohsjean, Alexander, Jeppe, Laurids, Knight, Charlotte, Mattelaer, Olivier, Mohrman, Kelci, Nelson, Hannah, Perovic, Vasilije, Presilla, Matteo, Schöfbeck, Robert, and Smith, Nick
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High Energy Physics - Phenomenology ,High Energy Physics - Experiment - Abstract
This note gives an overview of the tools for predicting expectations in the Standard Model effective field theory (SMEFT) at the tree level and one loop available through event generators. Methods of event reweighting, the separate simulation of squared matrix elements, and the simulation of the full SMEFT process are compared in terms of statistical efficacy and potential biases., Comment: 40 pages, 23 figures. Authorlist fixed
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- 2024
25. Development and Validation of a Machine Learning Algorithm for Clinical Wellness Visit Classification in Cats and Dogs
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Szlosek, Donald, Coyne, Michael, Riggot, Julia, Knight, Kevin, McCrann, DJ, and Kincaid, Dave
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Computer Science - Machine Learning ,Computer Science - Computers and Society - Abstract
Early disease detection in veterinary care relies on identifying subclinical abnormalities in asymptomatic animals during wellness visits. This study introduces an algorithm designed to distinguish between wellness and other veterinary visits.The purpose of this study is to validate the use of a visit classification algorithm compared to manual classification of veterinary visits by three board-certified veterinarians. Using a dataset of 11,105 clinical visits from 2012 to 2017 involving 655 animals (85.3% canines and 14.7% felines) across 544 U.S. veterinary establishments, the model was trained using a Gradient Boosting Machine model. Three validators were tasked with classifying 400 visits, including both wellness and other types of visits, selected randomly from the same database used for initial algorithm training, aiming to maintain consistency and relevance between the training and application phases; visit classifications were subsequently categorized into "wellness" or "other" based on majority consensus among validators to assess the algorithm's performance in identifying wellness visits. The algorithm demonstrated a specificity of 0.94 (95% CI: 0.91 to 0.96), implying its accuracy in distinguishing non-wellness visits. The algorithm had a sensitivity of 0.86 (95% CI: 0.80 to 0.92), indicating its ability to correctly identify wellness visits as compared to the annotations provided by veterinary experts. The balanced accuracy, calculated as 0.90 (95% CI: 0.87 to 0.93), further confirms the algorithm's overall effectiveness. The algorithm exhibits strong specificity and sensitivity, ensuring accurate identification of a high proportion of wellness visits. Overall, this algorithm holds promise for advancing research on preventive care's role in subclinical disease identification, but prospective studies are needed for validation., Comment: 21 pages, 2 figures, 4 tables
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- 2024
26. Power Analysis for Experiments with Clustered Data, Ratio Metrics, and Regression for Covariate Adjustment
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Hesterberg, Tim and Knight, Ben
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Statistics - Methodology ,Mathematics - Statistics Theory ,Primary 62K99, Secondary 62P30 ,G.3 - Abstract
We describe how to calculate standard errors for A/B tests that include clustered data, ratio metrics, and/or covariate adjustment. We may do this for power analysis/sample size calculations prior to running an experiment using historical data, or after an experiment for hypothesis testing and confidence intervals. The different applications have a common framework, using the sample variance of certain residuals. The framework is compatible with modular software, can be plugged into standard tools, doesn't require computing covariance matrices, and is numerically stable. Using this approach we estimate that covariate adjustment gives a median 66% variance reduction for a key metric, reducing experiment run time by 66%., Comment: 17 pages, 6 figures
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- 2024
27. Skeletal Density Measurements for Adsorbent Nanomaterials
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Gillespie, Andrew K., Piskulich, Zeke A., Knight, Ernest, Prosniewski, Matthew, and Pfeifer, Peter
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Condensed Matter - Materials Science ,Physics - Applied Physics - Abstract
Due to their tunable material properties, sorptive materials have a wide range of applications in energy storage, water treatment, carbon capture, analytical chemistry, and more. One crucial factor in determining the effectiveness of such materials is their skeletal density, or "true density" because it is often used to calculate key metrics, such as storage capacities. In this paper, we present skeletal density measurements through helium pycnometry for several types of adsorbent carbon materials derived from either corncob, sawdust, coffee grounds, polyvinylidene chloride (PVDC), graphitic carbon nitride (GCN), or metal organic frameworks (MOFs). The measured skeletal density of sawdust-based activated carbon was 2.02 +/- 0.05 g/$cm^{ 3}$. The measured skeletal density of coffee-based activated carbon was 2.23 +/- 0.06 $cm^{ 3}$. We also expound upon the impact that skeletal density has upon hydrogen excess adsorption measurements and other calculated engineering quantities. If a skeletal density is underestimated by 10%, it can affect the room temperature excess adsorption by at least 5% at 100 bar and by 7% at 200 bar, depending on the material type., Comment: 12 pages, 4 figures, 2 tables
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- 2024
28. No winners: Performance of lung cancer prediction models depends on screening-detected, incidental, and biopsied pulmonary nodule use cases
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Li, Thomas Z., Xu, Kaiwen, Krishnan, Aravind, Gao, Riqiang, Kammer, Michael N., Antic, Sanja, Xiao, David, Knight, Michael, Martinez, Yency, Paez, Rafael, Lentz, Robert J., Deppen, Stephen, Grogan, Eric L., Lasko, Thomas A., Sandler, Kim L., Maldonado, Fabien, and Landman, Bennett A.
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Quantitative Biology - Quantitative Methods - Abstract
Statistical models for predicting lung cancer have the potential to facilitate earlier diagnosis of malignancy and avoid invasive workup of benign disease. Many models have been published, but comparative studies of their utility in different clinical settings in which patients would arguably most benefit are scarce. This study retrospectively evaluated promising predictive models for lung cancer prediction in three clinical settings: lung cancer screening with low-dose computed tomography, incidentally detected pulmonary nodules, and nodules deemed suspicious enough to warrant a biopsy. We leveraged 9 cohorts (n=898, 896, 882, 219, 364, 117, 131, 115, 373) from multiple institutions to assess the area under the receiver operating characteristic curve (AUC) of validated models including logistic regressions on clinical variables and radiologist nodule characterizations, artificial intelligence on chest CTs, longitudinal imaging AI, and multi-modal approaches. We implemented each model from their published literature, re-training the models if necessary, and curated each cohort from primary data sources. We observed that model performance varied greatly across clinical use cases. No single predictive model emerged as a clear winner across all cohorts, but certain models excelled in specific clinical contexts. Single timepoint chest CT AI performed well in lung screening, but struggled to generalize to other clinical settings. Longitudinal imaging and multimodal models demonstrated comparatively promising performance on incidentally-detected nodules. However, when applied to nodules that underwent biopsy, all models underperformed. These results underscore the strengths and limitations of 8 validated predictive models and highlight promising directions towards personalized, noninvasive lung cancer diagnosis., Comment: Submitted to Radiology: AI
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- 2024
29. Uncovering implementable dormant pruning decisions from three different stakeholder perspectives
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Flynn, Deanna, Jain, Abhinav, Knight, Heather, Wilson, Cristina G., and Grimm, Cindy
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Computer Science - Robotics - Abstract
Dormant pruning, or the removal of unproductive portions of a tree while a tree is not actively growing, is an important orchard task to help maintain yield, requiring years to build expertise. Because of long training periods and an increasing labor shortage in agricultural jobs, pruning could benefit from robotic automation. However, to program robots to prune branches, we first need to understand how pruning decisions are made, and what variables in the environment (e.g., branch size and thickness) we need to capture. Working directly with three pruning stakeholders -- horticulturists, growers, and pruners -- we find that each group of human experts approaches pruning decision-making differently. To capture this knowledge, we present three studies and two extracted pruning protocols from field work conducted in Prosser, Washington in January 2022 and 2023. We interviewed six stakeholders (two in each group) and observed pruning across three cultivars -- Bing Cherries, Envy Apples, and Jazz Apples -- and two tree architectures -- Upright Fruiting Offshoot and V-Trellis. Leveraging participant interviews and video data, this analysis uses grounded coding to extract pruning terminology, discover horticultural contexts that influence pruning decisions, and find implementable pruning heuristics for autonomous systems. The results include a validated terminology set, which we offer for use by both pruning stakeholders and roboticists, to communicate general pruning concepts and heuristics. The results also highlight seven pruning heuristics utilizing this terminology set that would be relevant for use by future autonomous robot pruning systems, and characterize three discovered horticultural contexts (i.e., environmental management, crop-load management, and replacement wood) across all three cultivars., Comment: 36 pages; 21 figures
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- 2024
30. The enduring relevance of the Jaynes-Cummings model: a personal perspective
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Knight, P. L., Gerry, C. C., Birrittella, R. J., and Alsing, P. M.
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Quantum Physics - Abstract
In this short perspective article we present our personal highlights on how the Jaynes-Cummings model has become a central model to describe spin-boson couplings underpinning much of modern quantum optics. To the current authors, the key contribution is a demonstration of a measurable effect that showed the discreteness of the quantized radiation field., Comment: This paper was prepared as part of a special issue to the Journal of the Optical Society to commemorate the 60th anniversary of the Jaynes-Cummings model
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- 2024
31. Engineering superpositions of N00N states using an asymmetric non-linear Mach-Zehnder interferometer
- Author
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Birrittella, R. J., Alsing, P. M., Schneeloch, J., Gerry, C. C., Mimih, J., and Knight, P. L.
- Subjects
Quantum Physics - Abstract
We revisit a method for mapping arbitrary single-mode pure states into superpositions of N00N states using an asymmetric non-linear Mach-Zehnder interferometer (ANLMZI). This method would allow for one to tailor-make superpositions of N00N states where each axis of the two-mode joint-photon number distribution is weighted by the statistics of any single-mode pure state. The non-linearity of the ANLMZI comes in the form of a $\chi^{\left(3\right)}$ self-Kerr interaction occurring on one of the intermediary modes of the interferometer. Motivated by the non-classical interference effects that occur at a beam splitter, we introduce inverse-engineering techniques aimed towards extrapolating optimal transformations for generating N00N state superpositions. These techniques are general enough so as to be employed to probe the means of generating states of any desired quantum properties., Comment: This paper was prepared for AVS Quantum as part of a commemorative issue for Jonathan Dowling
- Published
- 2024
32. VISION: Toward a Standardized Process for Radiology Image Management at the National Level
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Knight, Kathryn, Danciu, Ioana, Ovchinnikova, Olga, Hinkle, Jacob, Shekar, Mayanka Chandra, Mukherjee, Debangshu, McAllister, Eileen, Rizy, Caitlin, Cho, Kelly, Justice, Amy C., Erdos, Joseph, Kuzmak, Peter, Costa, Lauren, Ho, Yuk-Lam, Madipadga, Reddy, Tamang, Suzanne, and Goethert, Ian
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
The compilation and analysis of radiological images poses numerous challenges for researchers. The sheer volume of data as well as the computational needs of algorithms capable of operating on images are extensive. Additionally, the assembly of these images alone is difficult, as these exams may differ widely in terms of clinical context, structured annotation available for model training, modality, and patient identifiers. In this paper, we describe our experiences and challenges in establishing a trusted collection of radiology images linked to the United States Department of Veterans Affairs (VA) electronic health record database. We also discuss implications in making this repository research-ready for medical investigators. Key insights include uncovering the specific procedures required for transferring images from a clinical to a research-ready environment, as well as roadblocks and bottlenecks in this process that may hinder future efforts at automation.
- Published
- 2024
33. Opinion Update in a Subjective Logic Model for Social Networks
- Author
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Alvim, Mário S., Knight, Sophia, and Oliveira, José C.
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Computer Science - Multiagent Systems ,Computer Science - Logic in Computer Science - Abstract
Subjective Logic (SL) is a logic incorporating uncertainty and opinions for agents in dynamic systems. In this work, we investigate the use of subjective logic to model opinions and belief change in social networks. In particular, we work toward the development of a subjective logic belief/opinion update function appropriate for modeling belief change as communication occurs in social networks. We found through experiments that an update function with belief fusion from SL does not have ideal properties to represent a rational update. Even without these properties, we found that an update function with cumulative belief fusion can describe behaviors not explored by the social network model defined by Alvim, Knight, and Valencia (2019).
- Published
- 2024
34. Untangling Critical Interaction with AI in Students Written Assessment
- Author
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Shibani, Antonette, Knight, Simon, Kitto, Kirsty, Karunanayake, Ajanie, and Shum, Simon Buckingham
- Subjects
Computer Science - Human-Computer Interaction ,Computer Science - Artificial Intelligence ,I.2 ,K.3.1 - Abstract
Artificial Intelligence (AI) has become a ubiquitous part of society, but a key challenge exists in ensuring that humans are equipped with the required critical thinking and AI literacy skills to interact with machines effectively by understanding their capabilities and limitations. These skills are particularly important for learners to develop in the age of generative AI where AI tools can demonstrate complex knowledge and ability previously thought to be uniquely human. To activate effective human-AI partnerships in writing, this paper provides a first step toward conceptualizing the notion of critical learner interaction with AI. Using both theoretical models and empirical data, our preliminary findings suggest a general lack of Deep interaction with AI during the writing process. We believe that the outcomes can lead to better task and tool design in the future for learners to develop deep, critical thinking when interacting with AI.
- Published
- 2024
- Full Text
- View/download PDF
35. Conceptual models of groundwater flow in the Grand Canyon region, Arizona
- Author
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Knight, Jacob E.
- Subjects
Hydrologic models -- Arizona -- Grand Canyon. ,Groundwater flow -- Arizona -- Grand Canyon. ,Groundwater -- Quality -- Arizona -- Grand Canyon. - Published
- 2022
36. Improving knowledge of quality and safety among general and acute care medicine advanced trainees through a brief quality improvement workshop
- Author
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Aung, Ar Kar, Ryall, Mary-Ann, Davis, Sarah, Shukla, Aditi, Knight, Anne, and Lee, Jennifer I
- Published
- 2024
37. Preparing the Teachers of Our Youngest Children: The State of Early Childhood Higher Education in Indiana Revisited. Report
- Author
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University of California, Berkeley. Center for the Study of Child Care Employment, Jenna Knight, Elizabeth Pufall Jones, and Yoonjeon Kim
- Abstract
Stakeholders and advocates in Indiana are committed to advancing strategies that improve ECE services, including workforce preparation and development, to ensure that early educators can meet the complex needs of young children. Critical to these efforts is the establishment of a well-coordinated, comprehensive professional preparation and development system that can train and support a diverse generation of pre-service educators, while also strengthening the skills of the existing ECE workforce. This study looks at how Indiana early childhood higher education programs have changed since 2015. The report describes the early childhood degree programs offered in Indiana, focusing on variations in program content, age group focus, and student field-based learning.
- Published
- 2023
38. Educating African Immigrant Youth: Schooling and Civic Engagement in K-12 Schools. Language and Literacy Series
- Author
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Vaughn W. M. Watson, Michelle G. Knight-Manuel, Patriann Smith, Vaughn W. M. Watson, Michelle G. Knight-Manuel, and Patriann Smith
- Abstract
This book illuminates emerging perspectives and possibilities of the vibrant schooling and civic lives of Black African youth and communities in the United States, Canada, and globally. Chapters present key research on how to develop and enact teaching methodologies and research approaches that support Black African immigrant and refugee students. The contributors examine contours of the Framework for Educating African Immigrant Youth, which focuses on four complementary approaches for teaching and learning: emboldening tellings of diaspora narratives; navigating the complex past, present, and future of teaching and learning; enacting social civic literacies to extend complex identities; and affirming and extending cultural, heritage, and embodied knowledges, languages, and practices. The frameworks and practices will strengthen how educators address the interplay of identities presented by African and, by extension, Black immigrant populations. Disciplinary perspectives include literacy and language, social studies, civics, mathematics, and higher education; university and community partnerships; teacher education; global and comparative education; and after-school initiatives. Book Features: (1) A focus on honoring and affirming the range of youth and community's diverse, embodied, social-civic literacies and lived experiences as part of their educational journey, reframing harmful narratives of immigrant youth, families, and Africa; (2) Chapter authors that include Black African scholars, early-career, and senior scholars from a range of institutions, including in the United States and Canada; (3) Chapters that draw on and extend a range of theoretical lenses grounded in African epistemologies and ontologies, as well as postcolonial and/or decolonizing approaches, culturally relevant and sustaining frameworks, language and literacy as a social practice, transnationalism, theater as social action, transformative and asset-based processes and practices, migration, and emotional capital, and more; and (4) A cross-disciplinary approach that addresses the scope and heterogeneity of African immigrant youth racialized as Black and their schooling, education, and civic engagement experiences. Implications are considered for teachers, teacher educators, and community educators.
- Published
- 2024
39. Words Matter: Reframing Communication Sciences and Disorders Programs' Thinking about Adolescents
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Kristin Nellenbach, Carrie Knight, and Bailey Jennings
- Abstract
Purpose: The purpose of this investigation was to evaluate language development and disorders course titles across communication sciences and disorders (CSD) graduate programs in an effort to determine whether adolescents were specifically being recognized via inclusive language or dedicated courses. The findings can be used to propel important discussions about the need for inclusive course titles, inform initial directions for improvements in preprofessional education, and guide broader changes in the discipline, especially for the adolescent population. Method: A review of accredited CSD graduate programs across the United States was conducted using the American Speech-Language-Hearing Association EdFind database. A total of 298 master's-level CSD programs were used for this study. CSD course titles located in each of the university's graduate catalogs were documented, categorized, and reviewed by the research team. Results: Of the 298 CSD graduate programs reviewed, one in eight specifically included the word "adolescent(s)" or "adolescence" in the titles of their language development and disorders courses. Remarkably, only four adolescent-focused courses, two of which were listed as electives, were offered across all reviewed programs. A post hoc analysis of the language used in course titling revealed that 42 titles used inclusive terminology. Conclusions: Adolescents are developmentally distinct from children, yet a majority of CSD graduate programs used ambiguous or exclusive words in the titles of their language development and disorders courses. The unintentional failure to recognize this important difference in course titles may be contributing to the ongoing neglect of adolescents within the field. Reframing collective thinking is required for change. Reasons and suggestions for including adolescents in course titles and separate offerings are provided to assist CSD graduate programs in leading the way toward improving equity for adolescents.
- Published
- 2024
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40. A Review of Group Design Studies of Reading Comprehension Interventions for Students with ASD
- Author
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Leigh Ann Tipton-Fisler and Erin Knight
- Abstract
This review aimed to synthesize the group design literature to identify the evidence-based reading comprehension interventions for children with ASD. The primary aim was to identify which reading comprehension interventions had demonstrated positive effects for students with ASD in group design studies. This review was initiated using both PsychInfo and ERIC in October 2019 with a second review completed in April 2020. For studies to be included, they had to include pre-/post-data on a reading comprehension intervention and include students with ASD as well as to be (1) peer-reviewed, (2) written in English, and (3) published between 2000 and 2019. The decision to review articles from 2000 forward was based on the publication of the National Reading Panel report (2000) and the wealth of research on the Big Five areas of reading. Five studies were found that met criteria, with a total of 141 students and 87% of the intervention group meeting criteria for ASD. Results showed effectiveness for reading comprehension interventions using anaphoric questions, direct instruction, and comprehension training strategies. These instructional strategies are consistent with single-case design study findings showing efficacy for these strategies with individual students and are important in supporting the variability of executive functioning skills needed for integrating passage information with whole group instruction as well.
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- 2024
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41. Speaking on One's Own Terms: Oracy and Orality as Partners in Classroom Talk
- Author
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Rupert Knight
- Abstract
Spoken language in schools, now often branded as oracy, is seeing something of a resurgence of interest. This is well-founded and to be welcomed. Nevertheless, the policy-level coopting of oracy, as a concept open to various interpretations, raises questions concerning the desirable degree of prescription and conformity to be promoted in pupils' spoken language. Though often encompassing talk as pedagogy, oracy is strongly associated with developing the skills of spoken language. Such skills rest on a number of assumptions and norms around participation in talk that merit examination. This article explores common classroom orthodoxies in terms of who speaks, when they may speak and how they must speak. As a way of examining these orthodoxies, the article proposes a greater acknowledgement of "orality" alongside, and as a precursor to, oracy. Using an illustration from a real lesson, it argues that raising the profile of orality is a reminder of the importance of understanding and appreciating specific and diverse oral traditions before bringing to bear the generalities and possible standardisation of oracy.
- Published
- 2024
42. 'It's Like a Compass Which I Use to Find Direction': Findings and Learning from an Evaluation of an App Designed to Support the Teaching of Reading Comprehension in Rural and Township Schools in South Africa
- Author
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Jane Carter, Pravina Pillay, Tessa Podpadec, Jethro Gina, Nontobeko Khumalo, Ben Knight, Paul Matthews, Lindiwe Mthethwa, and Karan Vickers-Hulse
- Abstract
South Africa has low literacy levels and teachers face multiple challenges in their endeavours to elevate levels of literacy. This is especially prevalent in rural and township schools where teachers face the additional challenges of isolation, limited resources and access to professional development. This article reports on the findings and learning from a preliminary research study which piloted a handheld mobile phone App. This collaborative project, between a university in KwaZulu-Natal and one in England, aimed to support in-service and preservice teachers in rural and township settings to use the App to assess and match books to learners' (aged 9-12) stage of reading development in order to facilitate their independent reading and provide teachers with a range of strategies for teaching comprehension that could supplement other professional development available. In-service teachers (n = 120) and preservice teachers (n = 93) took part in this mixed-methods study. The main finding from the study was that whilst participants were positive about the App, many did not access the App independently. This article discusses the broader issues, including participants' foundational knowledge and literacy research participation considerations, that may have underpinned this finding in this collaborative Global North and South research.
- Published
- 2024
- Full Text
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43. What Engineering Employers Want: An Analysis of Technical and Professional Skills in Engineering Job Advertisements
- Author
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Gabriella Coloyan Fleming, Michelle Klopfer, Andrew Katz, and David Knight
- Abstract
Background: Engineering curricula are built around faculty and accreditors' perceptions of what knowledge, skills, and abilities graduates will need in engineering careers. However, the people making these decisions may not be fully aware of what industry employers require for engineering graduates. Purpose/Hypothesis: The purpose of this study is to determine how industry employer-sought professional and technical skills vary among engineering disciplines and levels of education. Design/Method: Using a large sample (n = 26,103) of mined job advertisements, we use the O*NET skills database to determine the frequencies of different professional and technical skills for biomedical, civil, chemical, electrical, environmental, and mechanical engineers with bachelor's, master's, and PhD degrees. Results: The most frequently sought professional skill is problem-solving; the most frequently sought technical skills across disciplines are Microsoft Office software and computer-aided design software. Although not the most frequently requested skills, job advertisements including the Python and MATLAB programming languages paid significantly higher salaries than those without. Conclusions: The findings of this study have important implications for engineering program leaders and curriculum designers choosing which skills to teach students so that they are best prepared to get and excel in engineering jobs. The results also show which skills students can prioritize investing their time in so that they receive the largest financial return on their investment.
- Published
- 2024
- Full Text
- View/download PDF
44. Chatbot Responses Suggest That Hypothetical Biology Questions Are Harder than Realistic Ones
- Author
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Gregory J. Crowther, Usha Sankar, Leena S. Knight, Deborah L. Myers, Kevin T. Patton, Lekelia D. Jenkins, and Thomas A. Knight
- Abstract
The biology education literature includes compelling assertions that unfamiliar problems are especially useful for revealing students' true understanding of biology. However, there is only limited evidence that such novel problems have different cognitive requirements than more familiar problems. Here, we sought additional evidence by using chatbots based on large language models as models of biology students. For human physiology and cell biology, we developed sets of realistic and hypothetical problems matched to the same lesson learning objectives (LLOs). Problems were considered hypothetical if (i) known biological entities (molecules and organs) were given atypical or counterfactual properties (redefinition) or (ii) fictitious biological entities were introduced (invention). Several chatbots scored significantly worse on hypothetical problems than on realistic problems, with scores declining by an average of 13%. Among hypothetical questions, redefinition questions appeared especially difficult, with many chatbots scoring as if guessing randomly. These results suggest that, for a given LLO, hypothetical problems may have different cognitive demands than realistic problems and may more accurately reveal students' ability to apply biology core concepts to diverse contexts. The Test Question Templates (TQT) framework, which explicitly connects LLOs with examples of assessment questions, can help educators generate problems that are challenging (due to their novelty), yet fair (due to their alignment with pre-specified LLOs). Finally, ChatGPT's rapid improvement toward expert-level answers suggests that future educators cannot reasonably expect to ignore or outwit chatbots but must do what we can to make assessments fair and equitable.
- Published
- 2023
- Full Text
- View/download PDF
45. A Prebiotic Diet Containing Galactooligosaccharides and Polydextrose Produces Dynamic and Reproducible Changes in the Gut Microbial Ecosystem in Male Rats.
- Author
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Thompson, Robert, Bowers, Samuel, Vargas, Fernando, Hopkins, Shelby, Kelley, Tel, Gonzalez, Antonio, Lowry, Christopher, Dorrestein, Pieter, Vitaterna, Martha, Turek, Fred, Knight, Rob, Wright, Kenneth, and Fleshner, Monika
- Subjects
Parabacteroides ,Ruminiclostridium 5 ,bile acid ,deoxycholic acid ,galactooligosaccharide ,metabolome ,microbiome ,polydextrose ,prebiotic ,Animals ,Prebiotics ,Male ,Gastrointestinal Microbiome ,Rats ,Sprague-Dawley ,Oligosaccharides ,Glucans ,Rats ,Bile Acids and Salts ,Feces ,Bacteria ,RNA ,Ribosomal ,16S ,Diet - Abstract
Despite substantial evidence supporting the efficacy of prebiotics for promoting host health and stress resilience, few experiments present evidence documenting the dynamic changes in microbial ecology and fecal microbially modified metabolites over time. Furthermore, the literature reports a lack of reproducible effects of prebiotics on specific bacteria and bacterial-modified metabolites. The current experiments examined whether consumption of diets enriched in prebiotics (galactooligosaccharides (GOS) and polydextrose (PDX)), compared to a control diet, would consistently impact the gut microbiome and microbially modified bile acids over time and between two research sites. Male Sprague Dawley rats were fed control or prebiotic diets for several weeks, and their gut microbiomes and metabolomes were examined using 16S rRNA gene sequencing and untargeted LC-MS/MS analysis. Dietary prebiotics altered the beta diversity, relative abundance of bacterial genera, and microbially modified bile acids over time. PICRUSt2 analyses identified four inferred functional metabolic pathways modified by the prebiotic diet. Correlational network analyses between inferred metabolic pathways and microbially modified bile acids revealed deoxycholic acid as a potential network hub. All these reported effects were consistent between the two research sites, supporting the conclusion that dietary prebiotics robustly changed the gut microbial ecosystem. Consistent with our previous work demonstrating that GOS/PDX reduces the negative impacts of stressor exposure, we propose that ingesting a diet enriched in prebiotics facilitates the development of a health-promoting gut microbial ecosystem.
- Published
- 2024
46. Scaling DEPP phylogenetic placement to ultra-large reference trees: a tree-aware ensemble approach.
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Jiang, Yueyu, McDonald, Daniel, Perry, Daniela, Knight, Rob, and Mirarab, Siavash
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Phylogeny ,Algorithms ,RNA ,Ribosomal ,16S ,Software ,Computational Biology ,Machine Learning ,Sequence Analysis ,DNA - Abstract
MOTIVATION: Phylogenetic placement of a query sequence on a backbone tree is increasingly used across biomedical sciences to identify the content of a sample from its DNA content. The accuracy of such analyses depends on the density of the backbone tree, making it crucial that placement methods scale to very large trees. Moreover, a new paradigm has been recently proposed to place sequences on the species tree using single-gene data. The goal is to better characterize the samples and to enable combined analyses of marker-gene (e.g., 16S rRNA gene amplicon) and genome-wide data. The recent method DEPP enables performing such analyses using metric learning. However, metric learning is hampered by a need to compute and save a quadratically growing matrix of pairwise distances during training. Thus, the training phase of DEPP does not scale to more than roughly 10 000 backbone species, a problem that we faced when trying to use our recently released Greengenes2 (GG2) reference tree containing 331 270 species. RESULTS: This paper explores divide-and-conquer for training ensembles of DEPP models, culminating in a method called C-DEPP. While divide-and-conquer has been extensively used in phylogenetics, applying divide-and-conquer to data-hungry machine-learning methods needs nuance. C-DEPP uses carefully crafted techniques to enable quasi-linear scaling while maintaining accuracy. C-DEPP enables placing 20 million 16S fragments on the GG2 reference tree in 41 h of computation. AVAILABILITY AND IMPLEMENTATION: The dataset and C-DEPP software are freely available at https://github.com/yueyujiang/dataset_cdepp/.
- Published
- 2024
47. Experiences of alcohol use during pregnancy: A qualitative study of pregnant women at risk of acquiring HIV in Cape Town, South Africa
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Miller, Amanda P, Court, Lara, Schoetz, Sarah, Knight, Lucia, Moopelo, Kearabetswe, Ntwasa, Chwayita, Wara, Nafisa, Essack, Zaynab, Shoptaw, Steven, Myer, Landon, and Davey, Dvora Joseph
- Subjects
Reproductive Medicine ,Biomedical and Clinical Sciences ,Human Society ,Alcoholism ,Alcohol Use and Health ,Pregnancy ,Pediatric ,Women's Health ,Behavioral and Social Science ,Infectious Diseases ,Substance Misuse ,Sexually Transmitted Infections ,Maternal Health ,Violence Against Women ,Prevention ,HIV/AIDS ,Clinical Research ,Social Determinants of Health ,Perinatal Period - Conditions Originating in Perinatal Period ,Violence Research ,Reproductive health and childbirth ,Cardiovascular ,Good Health and Well Being ,Gender Equality ,Alcohol use ,HIV ,Intimate partner violence ,South Africa - Abstract
In South Africa, alcohol use during pregnancy is prevalent and associated with increased HIV risk. Developing locally sensitive and contextually appropriate evidence-based interventions to address alcohol use among pregnant and breastfeeding women in South Africa requires comprehensive understanding of the context of perinatal alcohol use and how relationships and lived environments may serve as barriers or supports for alcohol reduction. We conducted twenty in-depth qualitative interviews with isiXhosa speaking women who reported alcohol use during their recent pregnancy and/or recent intimate partner violence in Cape Town, South Africa between September and November 2022. We describe patterns and drivers of ongoing alcohol use during pregnancy and map them onto levels of the socioecological model. Data were analyzed utilizing the interpretivist paradigm and interpretive thematic analysis. Eight women reported alcohol use during pregnancy, sixteen reported experiencing recent IPV, and four women reported both alcohol use during pregnancy and recent IPV. In interviews, commonly cited reasons for continued alcohol use in pregnancy included stress (e.g., due to financial concerns), peer pressure, the central role of alcohol use in socialization and the persistence of misconceptions regarding the safety of alcohol use in pregnancy. Still, despite women reporting social norms that supported continued alcohol use in pregnancy, many altered who they drank with due to fear of judgement from close friends and family, leaving them isolated from their social support system. Interventions aimed at increasing interpersonal support, such as the use of peer mentors, could prove beneficial. Although the clinic provides messaging around the harms of alcohol use in pregnancy, these messages conflict with messaging received from their peers, limiting their impact on behavior. Locally sensitive tailored, relevant programming that intervenes on barriers to reducing alcohol use in pregnancy at multiple levels of the socioeconomic model are vital to effectively addressing this public health issue.
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- 2024
48. Integrated Genomic and Social Network Analyses of SARS-CoV-2 Transmission in the Healthcare Setting
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Keehner, Jocelyn, Abeles, Shira R, Longhurst, Christopher A, Horton, Lucy E, Myers, Frank E, Riggs-Rodriguez, Lindsay, Ahmad, Mohammed, Baxter, Sally, Boussina, Aaron, Cantrell, Kalen, Cardenas, Priscilla, De Hoff, Peter, El-Kareh, Robert, Holland, Jennifer, Ikeda, Daryn, Kurashige, Kirk, Laurent, Louise C, Aigner, Stefan, Andersen, Kristian G, Anderson, Catelyn, Baer, Nathan A, Barber, Tom, Bauk, Marco, Beck, Jennifer N, Belda-Ferre, Pedro, Betty, Maryann, Birmingham, Amanda, Castro-Martinez, Anelizze, Cheung, Willi, Fisch, Kathleen M, Gangavarapu, Karthik, Gargano, Isabella, Hakim, Abbas, Harsono, Shania, Henson, Benjamin, Hobbs, Charlotte, Holmes, Jacqueline, Jepsen, Kristen, Knight, Rob, Kurzban, Ezra, Marotz, Clarisse A, Matteson, Nathaniel L, Moshiri, Niema, Ngo, Toan T, Ostrander, Tyler R, Perkins, Sarah, Plascencia, Ashley, Rivera, Andrea, Rivera, Ariana, Salido, Rodolfo A, Sathe, Shashank, Seaver, Phoebe, Schwab, Madison, Veder, Anthony, Yeo, Gene W, Zeller, Mark, Lucas, Andrew, Pride, David, Tran, Allen R, Vasylyeva, Tetyana I, Yeo, Gene, Wertheim, Joel O, and Torriani, Francesca J
- Subjects
Medical Microbiology ,Biomedical and Clinical Sciences ,Pneumonia & Influenza ,Clinical Research ,Emerging Infectious Diseases ,Infectious Diseases ,Biodefense ,Lung ,Genetics ,Vaccine Related ,Prevention ,Aetiology ,2.2 Factors relating to the physical environment ,Infection ,Good Health and Well Being ,Humans ,COVID-19 ,SARS-CoV-2 ,Retrospective Studies ,Cross-Sectional Studies ,Health Personnel ,Male ,Genome ,Viral ,Female ,Adult ,Middle Aged ,Aged ,Social Network Analysis ,Contact Tracing ,Genomics ,Young Adult ,Adolescent ,Child ,Aged ,80 and over ,Cross Infection ,Child ,Preschool ,SARS-CoV-2 pandemic ,infection prevention precautions ,healthcare transmission of SARS-CoV-2 ,whole-genome sequencing ,social network analyses and contact tracing ,SEARCH Alliance ,Biological Sciences ,Medical and Health Sciences ,Microbiology ,Clinical sciences - Abstract
BackgroundInfection prevention (IP) measures are designed to mitigate the transmission of pathogens in healthcare. Using large-scale viral genomic and social network analyses, we determined if IP measures used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic were adequate in protecting healthcare workers (HCWs) and patients from acquiring SARS-CoV-2.MethodsWe performed retrospective cross-sectional analyses of viral genomics from all available SARS-CoV-2 viral samples collected at UC San Diego Health and social network analysis using the electronic medical record to derive temporospatial overlap of infections among related viromes and supplemented with contact tracing data. The outcome measure was any instance of healthcare transmission, defined as cases with closely related viral genomes and epidemiological connection within the healthcare setting during the infection window. Between November 2020 through January 2022, 12 933 viral genomes were obtained from 35 666 patients and HCWs.ResultsAmong 5112 SARS-CoV-2 viral samples sequenced from the second and third waves of SARS-CoV-2 (pre-Omicron), 291 pairs were derived from persons with a plausible healthcare overlap. Of these, 34 pairs (12%) were phylogenetically linked: 19 attributable to household and 14 to healthcare transmission. During the Omicron wave, 2106 contact pairs among 7821 sequences resulted in 120 (6%) related pairs among 32 clusters, of which 10 were consistent with healthcare transmission. Transmission was more likely to occur in shared spaces in the older hospital compared with the newer hospital (2.54 vs 0.63 transmission events per 1000 admissions, P < .001).ConclusionsIP strategies were effective at identifying and preventing healthcare SARS-CoV-2 transmission.
- Published
- 2024
49. Greengenes2 unifies microbial data in a single reference tree
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McDonald, Daniel, Jiang, Yueyu, Balaban, Metin, Cantrell, Kalen, Zhu, Qiyun, Gonzalez, Antonio, Morton, James T, Nicolaou, Giorgia, Parks, Donovan H, Karst, Søren M, Albertsen, Mads, Hugenholtz, Philip, DeSantis, Todd, Song, Se Jin, Bartko, Andrew, Havulinna, Aki S, Jousilahti, Pekka, Cheng, Susan, Inouye, Michael, Niiranen, Teemu, Jain, Mohit, Salomaa, Veikko, Lahti, Leo, Mirarab, Siavash, and Knight, Rob
- Subjects
Microbiology ,Biological Sciences ,Genetics ,Human Genome ,RNA ,Ribosomal ,16S ,Phylogeny ,Metagenomics ,Bacteria ,Databases ,Genetic ,Metagenome - Abstract
Studies using 16S rRNA and shotgun metagenomics typically yield different results, usually attributed to PCR amplification biases. We introduce Greengenes2, a reference tree that unifies genomic and 16S rRNA databases in a consistent, integrated resource. By inserting sequences into a whole-genome phylogeny, we show that 16S rRNA and shotgun metagenomic data generated from the same samples agree in principal coordinates space, taxonomy and phenotype effect size when analyzed with the same tree.
- Published
- 2024
50. Generation of accurate, expandable phylogenomic trees with uDance
- Author
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Balaban, Metin, Jiang, Yueyu, Zhu, Qiyun, McDonald, Daniel, Knight, Rob, and Mirarab, Siavash
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Biological Sciences ,Bioinformatics and Computational Biology ,Genetics ,Human Genome ,Generic health relevance ,Phylogeny ,Algorithms ,Genomics ,Software ,Evolution ,Molecular - Abstract
Phylogenetic trees provide a framework for organizing evolutionary histories across the tree of life and aid downstream comparative analyses such as metagenomic identification. Methods that rely on single-marker genes such as 16S rRNA have produced trees of limited accuracy with hundreds of thousands of organisms, whereas methods that use genome-wide data are not scalable to large numbers of genomes. We introduce updating trees using divide-and-conquer (uDance), a method that enables updatable genome-wide inference using a divide-and-conquer strategy that refines different parts of the tree independently and can build off of existing trees, with high accuracy and scalability. With uDance, we infer a species tree of roughly 200,000 genomes using 387 marker genes, totaling 42.5 billion amino acid residues.
- Published
- 2024
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