Physical Sciences and Mathematics Commons^™

Causal Mediation Analysis With Multiple Time-Varying Mediators, An-Shun Tai, Sheng-Hsuan Lin, Yu-Cheng Chu, Tsung Yu, Milo A. Puhan, Tyler Vanderweele

Harvard University Biostatistics Working Paper Series

In longitudinal studies with time-varying exposures and mediators, the mediational g-formula is an important method for the assessment of direct and indirect effects. However, current methodologies based on the mediational g-formula can deal with only one mediator. This limitation makes these methodologies inapplicable to many scenarios. Hence, we develop a novel methodology by extending the mediational g-formula to cover cases with multiple time-varying mediators. We formulate two variants of our approach that are each suited to a distinct set of assumptions and effect definitions and present nonparametric identification results of each variant. We further show how complex causal mechanisms (whose …

Saving The Last Unicorns: The Genetic Rescue Of Florida’S Pillar Corals, Karen L. Neely, Cynthia L. Lewis, Keri O’Neil, Cheryl M. Woodley, Jennifer Moore, Zach Ransom, Amelia Moura, Ken Nedimyer, David Vaughan

Marine & Environmental Sciences Faculty Articles

As stony coral tissue loss disease (SCTLD) swept through the Florida Reef Tract, one of the most severely impacted species was the iconic pillar coral, Dendrogyra cylindrus. As the species’ population experienced a precipitous decline, a collaborative rescue project collected colony fragments for safekeeping at onshore and offshore nursery facilities. Between 2015 and 2019, a total of 574 fragments representing 128 genotypes were collected. These are currently dispersed among five facilities where they continue to provide opportunities to (1) refine best husbandry practices for D. cylindrus, (2) develop treatment options for SCTLD that have been adapted for use …

Developing Pandemic Comics For Youth Audiences, Judy Diamond, Amy Spiegel, Patricia Wonch Hill, Elizabeth Vanwormer, Judi M. Gaiashkibos, Bob Hall, Aaron Sutherlen, Julia Mcquillan

University of Nebraska State Museum: Staff and Affiliates, Publications

In spring 2020 our team received funding from the Rapid Response Research program of the National Science Foundation to develop comics that would help youth understand the COVID-19 pandemic. Our project built on a decade of expertise creating comics about the biology of viruses. In collaboration with virologists and artists, we developed three comic stories about COVID-19 during the pandemic and posted them on-line during the last half of 2020. The fictional narratives address fundamental issues in biology, virology, and network science, in order to help readers understand the complexities of living through a viral pandemic. The stories focus on …

Structure-Guided Microbial Targeting Of Antistaphylococcal Prodrugs, Justin J. Miller, Ishaan T. Shah, Jayda Hatten, Yasaman Barekatain, Elizabeth A. Mueller, Ahmed M. Moustafa, Rachel L. Edwards, Cynthia S. Dowd, Geoffrey C. Hoops, R Jeremy Johnson

Scholarship and Professional Work - LAS

Carboxy ester prodrugs are widely employed to increase oral absorption and potency of phosphonate antibiotics. Prodrugging can mask problematic chemical features that prevent cellular uptake and may enable tissue-specific compound delivery. However, many carboxy ester promoieties are rapidly hydrolyzed by serum esterases, limiting their therapeutic potential. While carboxy ester-based prodrug targeting is feasible, it has seen limited use in microbes as microbial esterase-specific promoieties have not been described. Here we identify the bacterial esterases, GloB and FrmB, that activate carboxy ester prodrugs in Staphylococcus aureus. Additionally, we determine the substrate specificities for FrmB and GloB and demonstrate the structural basis …

Factors Controlling Longshore Variations Of Beach Changes Induced By Tropical Storm Eta Along Pinellas County Beaches, West-Central Florida, Francesca Luisa Toledo Cossu

USF Tampa Graduate Theses and Dissertations

Tropical Storm Eta impacted the coast of west-central Florida from November 11 to 12, 2020, and generated high waves over elevated water levels for over 20 hours. A total of 148 beach and nearshore profiles, spaced about 300 m apart, were surveyed one to two weeks before and one to eight days after the storm to examine the beach changes along four barrier islands, including Sand Key, Treasure Island, Long Key and Mullet Key. Storm waves superimposed on elevated water levels reached the toe of dunes, causing modest dune erosion as well as overwash in some areas. Most of the …

From Reaction Kinetics To Dementia: A Simple Dimer Model Of Alzheimer’S Disease Etiology, Michael R. Lindstrom, Manuel B. Chavez, Elijah A. Gross-Sable, Eric Y. Hayden, David B. Teplow

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Oligomers of the amyloid β-protein (Aβ) have been implicated in the pathogenesis of Alzheimer’s disease (AD) through their toxicity towards neurons. Understanding the process of oligomerization may contribute to the development of therapeutic agents, but this has been difficult due to the complexity of oligomerization and the metastability of the oligomers thus formed. To understand the kinetics of oligomer formation, and how that relates to the progression of AD, we developed models of the oligomerization process. Here, we use experimental data from cell viability assays and proxies for rate constants involved in monomerdimer-trimer kinetics to develop a simple mathematical model …

Projections Of Large-Scale Atmospheric Circulation Patterns And Associated Temperature And Precipitation Over The Pacific Northwest Using Cmip6 Models, Graham Patrick Taylor

Dissertations and Theses

Projections of 500 hPa geopotential height (Z500) patterns over the Pacific Northwest of North America and their associated surface temperature, precipitation, and frequency of occurrence are assessed using models from the 6th phase of the Coupled Model Intercomparison Project (CMIP6). The self-organizing maps approach is applied to reanalysis data from the Modern-Era Retrospective Analysis for Research and Applications, version-2 (MERRA-2) to cluster daily Z500 anomalies into 12 representative patterns that span the range of historical circulation patterns. CMIP6 data for daily Z500 anomalies are mapped to each node for historical and end of century global warming experiments, and the resulting …

A Ground-Based Assessment Framework For Validating Diesel Particulate Emission Models And Applicability In Portland, Or, Kirsten Marie Sarle

Dissertations and Theses

Exposure to diesel emissions causes a range of health effects throughout the body, impairing; respiratory, cardiovascular, central nervous, renal, and cognitive systems. Diesel particulate matter (DPM) in Portland, Oregon is prevalent due to the layout of highly trafficked roadways, rail lines, and marine ports exposing a dense population to high levels of exhaust pollution. These high concentrations of ambient diesel emissions disproportionately impact minority and low-income populations.

Ground-based monitoring and modeling are two ways to assess ambient DPM. However, there are uncertainties in modeled DPM due to knowledge gaps in emissions inventories as well as lack of model validation against …

3-Adic Properties Of Hecke Traces Of Singular Moduli, Miriam Beazer

Theses and Dissertations

As shown by Zagier, singular moduli can be represented by the coefficients of a certain half integer weight modular form. Congruences for singular moduli modulo arbitrary primes have been proved by Ahlgren and Ono, Edixhoven, and Jenkins. Computation suggests that stronger congruences hold for small primes $p \in \{2, 3, 5, 7, 11\}$. Boylan proved stronger congruences hold in the case where $p=2$. We conjecture congruences for singular moduli modulo powers of $p \in \{3, 5, 7, 11\}$. In particular, we study the case where $p=3$ and reduce the conjecture to a congruence for a simpler modular form.

Hidden Treasures In The Unknown 3cr Extragalactic Radio Sky: A Multiwavelength Approach, V. Missaglia, F. Massaro, E. Liuzzo, A. Paggi, R. P. Kraft, W. R. Forman, A. Jimenez-Gallardo, Juan P. Madrid, F. Ricci, C. Stuardi

Physics and Astronomy Faculty Publications and Presentations

We present the analysis of multiwavelength observations of seven extragalactic radio sources, listed as unidentified in the Third Cambridge Revised Catalog (3CR). X-ray observations, performed during Chandra Cycle 21, were compared to Very Large Array (VLA), Wide-field Infrared Survey Explorer, and Pan-STARRS observations in the radio, infrared, and optical bands, respectively. All sources in this sample lack a clear optical counterpart, and are thus missing their redshift and optical classification. In order to confirm the X-ray and infrared radio counterparts of core and extended components, here we present for the first time radio maps obtained manually reducing VLA archival data. …

Livestock, Rangelands And Grasslands‐-A Specific Case For The Management Of Genetic Resources For Food And Agriculture, Irene Hoffmann, David Boerma, Alvaro Toledo

IGC Proceedings (1993-2023)

No abstract provided.

Understanding The Social Determinants Of Sustainable Grassland Management — A Case‐Based Analysis Of 3 Tibetan Villages In Sichuan, China, Xiaoming Guo, Wei Han

IGC Proceedings (1993-2023)

No abstract provided.

Community‐Based Management Is The Basic Way To Realize Sustainable Use And Achieve Environmental Protection For Grasslands On The Tibetan Plateau, Guozhen Du, Jianjun Cao

IGC Proceedings (1993-2023)

No abstract provided.

A Policy To Strengthen Pastoral Communities And To Restore Cultural Landscapes For Climate Change Adaptation And Sustainability, T. Chuluun, S. Davaanyam, M. Altanbagana, D. S. Ojima

IGC Proceedings (1993-2023)

No abstract provided.

Reconsidering Effects Of Grassland Use Certificates In Xinjiang, Michael L. Zukosky

IGC Proceedings (1993-2023)

No abstract provided.

Health Disparity And Covid-19—A Retrospective Analysis, Sanjay Sarkar, Archie Taylor, Pratik Dutta, Bidisha Sengupta, Debarshi Roy

Faculty Publications

Background and Aims

According to the World Health Organization (WHO), more than 75.7 million confirmed cases of coronavirus disease 2019 (COVID-19), a global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have been reported so far. Researchers are working relentlessly to find effective solutions to this catastrophe, using genomic sequence-based investigation, immunological analysis, and more. The role of health disparity has also emerged as an intriguing factor that made a huge impact on the lives of people.

Methods

We analyzed various factors that triggered the health disparity in the United States of America along with the rate of …

Modeling Forage Yield Losses For Crop Insurance In Eastern Canada, I. Duchesne‐Ortiz, Gilles Bélanger, L. Martel, Guy Allard

IGC Proceedings (1993-2023)

No abstract provided.

A New Approach To Elicit And Aggregate Stakeholders' Preferences Towards Rangelands Policies: A Case Study Of Lar Rangeland, Iran, Kamran Zendehdel, Guido Van Huylenbroeck

IGC Proceedings (1993-2023)

No abstract provided.

Is Rangeland Co‐Management A Feasible Policy Option In China?, A. J. Wilkes, Y. Liang, Mandula, J. Z. Tan

IGC Proceedings (1993-2023)

No abstract provided.

To Fence Or Not To Fence—An Economic Study On The Decision‐Making Behavior Of Herders In Gannan Prefecture, Gansu Province, Huilan Wei, Guozhen Du, Xianglian Wu, Bin Lu

IGC Proceedings (1993-2023)

No abstract provided.

Hydrochloric Acid Modification And Lead Removal Studies On Naturally Occurring Zeolites From Nevada, New Mexico, And Arizona, Garven M. Huntley, Rudy Luck, Michael Mullins, Nick Newberry

Michigan Tech Publications

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving …

Landscape-Scale Drivers Of Resistance And Resilience To Bark Beetles: A Conceptual Susceptibility Model, Marcella A. Windmuller-Campione, R. Justin Derose, James N. Long

Wildland Resources Faculty Publications

Bark beetle (Dendroctonus spp.) outbreaks in the middle latitudes of western North America cause large amounts of tree mortality, outstripping wildfire by an order of magnitude. While temperatures play an important, and direct role in the population dynamics of ectothermic bark beetles, an equally important influence is the nature of the host substrate—the structure and composition of forested communities. For many of the dominant tree species in the western United States, “hazard” indices have been developed for specific bark beetles, which generally include three key variables—host tree size, absolute or relative density of the stand, and percentage of host composition. …

Late Miocene Unroofing Of The Inner Lesser Himalaya Recorded In The Nw Himalaya Foreland Basin, Elise Marie Exnicios

LSU Master's Theses

Testing models that link climate and solid Earth tectonics requires independent erosional, structural and climatic histories. Two well preserved stratigraphic sections of the Himalayan foreland basin are exposed in NW India. The Jawalamukhi (13–5 Ma) and Joginder Nagar sections (21–13 Ma) are dated by magnetostratigraphy and span a period of significant climate change and tectonic evolution. We use detrital zircon U-Pb dating and apatite fission track analyses to reconstruct changes in the patterns of erosion and exhumation in this area from the Early Miocene to Pliocene. The provenance of the foreland sediments shows that since at least ~21 Ma the …

Geospatial Technology In Sustainable Cities And Communities: Introduction To The Special Issue, Siti Aekbal Salleh, Zulkiflee Abd Latif, Nazri Che Dom

International Journal of Geospatial and Environmental Research

This special issue aims to demonstrate how we could leverage geospatial technology for sustainable cities and communities. Contributions on a wide range of geospatial technologies (e.g., GIS, remote sensing, spatial statistics, photogrammetry, and geomatics) as well as issues addressing better cities and communities for a sustainable future are encouraged. This issue contains selected papers from the 7th International Conference on Geomatics and Geospatial Technology (GGT) 2021, which took place in Kuala Lumpur, Malaysia, on 24th March 2021. The five articles selected for this special issue demonstrate how geospatial technology can be used to create more sustainable cities and communities. The …

Too Many People, Too Many Animals For Too Little Grass-‐A Canadian Perspective, G. Luciuk, M. Boyle, G. Brown, B. Kirychuk, B. Sonntag

IGC Proceedings (1993-2023)

No abstract provided.

Promoting Rangeland Biodiversity Conservation And Utilization Through Participatory Approaches In China, Keyu Bai, Zongwen Zhang

IGC Proceedings (1993-2023)

No abstract provided.

Golden‐Cheeked Warbler Habitat Conservation In Central Texas, Urs P. Kreuter, William E. Fox

IGC Proceedings (1993-2023)

No abstract provided.

How To Cope With Global Change? On The Potential Of Ecological‐Economic Modelling For Institutional Design, Karin Frank, Birgit Müller

IGC Proceedings (1993-2023)

No abstract provided.

Unsupervised Anomaly Instance Segmentation For Baggage Threat Recognition, Taimur Hassan, Samet Akçay, Mohammed Bennamoun, Salman Khan, Naoufel Werghi

Computer Vision Faculty Publications

Identifying potential threats concealed within the baggage is of prime concern for the security staff. Many researchers have developed frameworks that can automatically detect baggage threats from security X-ray scans. However, to the best of our knowledge, all of these frameworks require extensive training efforts on large-scale and well-annotated datasets, which are hard to procure in the real world, especially for the rarely seen contraband items. This paper presents a novel unsupervised anomaly instance segmentation framework that recognizes baggage threats, in X-ray scans, as anomalies without requiring any ground truth labels. Furthermore, thanks to its stylization capacity, the framework is …

Visualizing Amino Acid Substitutions In A Physicochemical Vector Space, Louis R. Nemzer

Chemistry and Physics Faculty Articles

A three-dimensional representation of the twenty proteinogenic amino acids in a physicochemical space is presented. Vectors corresponding to amino acid substitutions are classified based on whether they are accessible via a single-nucleotide mutation. It is shown that the standard genetic code establishes a “choice architecture” that permits nearly independent tuning of the properties related with size and those related with hydrophobicity. This work sheds light on the metarules of evolvability that may have shaped the standard genetic code to increase the probability that adaptive point mutations will be generated. An illustration of the usefulness of visualizing amino acid substitutions in …