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Articles 3871 - 3900 of 291657

Full-Text Articles in Physical Sciences and Mathematics

Investigation Of The Enzyme-Inhibitory, Antibacterial, And Anticancer Properties Of Metal Phthalocyanines, Meryem Topal, Fevzi̇ Topal, Firat Yilmaz, Esra Bulut Atalay, Ümi̇t Muhammet Koçyi̇ği̇t, Emre Güzel Apr 2026

Investigation Of The Enzyme-Inhibitory, Antibacterial, And Anticancer Properties Of Metal Phthalocyanines, Meryem Topal, Fevzi̇ Topal, Firat Yilmaz, Esra Bulut Atalay, Ümi̇t Muhammet Koçyi̇ği̇t, Emre Güzel

Turkish Journal of Chemistry

In this study, the enzyme inhibitory, antibacterial, and anticancer activities of a phthalonitrile derivative and its metal phthalocyanines (Pcs; indium, zinc, copper, cobalt, and manganese; 1–6) were investigated. The cobalt and manganese Pcs were synthesized for the first time in this study. The inhibitory activities of the symmetric Pcs, which were expected to interact with acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) via their 4-(isopropylbenzyl)oxy substituents through host–guest interactions, were investigated. More selective inhibition of AChE than BChE was observed for these compounds. For AChE, CoPc was identified as the most potent inhibitor (IC50 = 14.81 nM), whereas for BChE, InPc was …


Templating Effect Of Neutral Dithiane Ligands On The Self-Assembly Of Cationic Au(I)-Phosphine Units, Farzane Osanlou, Abdollah Neshat, Mohammad Reza Yousefshahi, Vaclav Eigner, Michal Dusek, Shahram Seidi Apr 2026

Templating Effect Of Neutral Dithiane Ligands On The Self-Assembly Of Cationic Au(I)-Phosphine Units, Farzane Osanlou, Abdollah Neshat, Mohammad Reza Yousefshahi, Vaclav Eigner, Michal Dusek, Shahram Seidi

Turkish Journal of Chemistry

The interactions between the dinuclear Au(I) precursor (dppm)Au2Cl2 and neutral sulfur-containing dithianes (specifically 1,3- and 1,4-dithiane) were examined in the presence of NH₄PF₆. Although these sulfur-based ligands were initially employed to facilitate the formation of mixed phosphine/sulfur Au(I) complexes, single-crystal X-ray diffraction analysis revealed the unexpected generation of multinuclear Au(I) assemblies exclusively coordinated by phosphine ligands. When 1,3-dithiane was present, a trinuclear Au(I) complex was isolated, characterized by a central four-coordinate Au(I) center exhibiting a distorted see-saw geometry, flanked by two terminal Au(I) centers with T-shaped coordination environments. Importantly, the dithiane ligand did not coordinate directly to the gold centers …


Nucleophilic Cyclization Of N-Propargylated Pyrazole-5-Carboxylates: Synthesis Of Pyrazolo[1,5-A]Pyrazin-4(5h)-One Derivatives, Meli̇k Firat Mengeş, Meltem Tan Uygun Apr 2026

Nucleophilic Cyclization Of N-Propargylated Pyrazole-5-Carboxylates: Synthesis Of Pyrazolo[1,5-A]Pyrazin-4(5h)-One Derivatives, Meli̇k Firat Mengeş, Meltem Tan Uygun

Turkish Journal of Chemistry

Cyclization reactions are among the most important and widely used methods for synthesizing biologically active fused heterocyclic compounds. In the present study, pyrazolopyrazinone derivatives (10a–i) were synthesized from N-propargylated pyrazoles via nucleophilic cyclization with hydrazine hydrate under a nitrogen atmosphere. Nuclear magnetic resonance (NMR) spectral analyses confirmed that ring closure proceeded in a manner consistent with the formation of a six-membered pyrazinone moiety. In addition, the pyrazolotriazepinone derivative 15c was synthesized using an alternative approach. In this method, substitution with chloroacetone was first carried out, followed by ring closure with hydrazine hydrate, affording a seven-membered triazepinone system. Comparison of the …


Bass Numbers Of Veronese Submodules And Lifting The Frobenius Trace, Taylor Jeffrey Murray Apr 2026

Bass Numbers Of Veronese Submodules And Lifting The Frobenius Trace, Taylor Jeffrey Murray

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The first part of this thesis is inspired by the works of G. Lyubeznik, C. Hunkeke, R. Sharp, and L. Núñez-Betancourt on Bass numbers, associated primes, and injective dimension of local cohomology modules. In particular, we study the question: how do Bass numbers behave under the Veronese functors? We show for a positive integer n, a reasonably nice, graded, finitely generated algebra over field R, and a graded module M, that if the Bass numbers of M are finite over R, then so are the Bass numbers of Mn/Rn; this recovers …


The Synthesis And Evaluation Of Thioxothiazolidin-4-One Compounds As Pim Kinase Inhibitors, Kelly Malzewski Apr 2026

The Synthesis And Evaluation Of Thioxothiazolidin-4-One Compounds As Pim Kinase Inhibitors, Kelly Malzewski

Master's Theses (2009 -)

The Proviral integration site for Moloney Murine Leukemia virus (PIM) kinases belongs to the family of serine/threonine kinases consisting of three isoforms; PIM1, PIM2, PIM3. PIM kinase is involved in multiple cellular processes through the phosphorylation of several proteins within the JAK/STAT pathway, leading to cell proliferation, apoptosis inhibition, cell migration, transcription, and energy metabolism. However, disruption or overexpression of PIM within the cycle can have negative, tumorigenesis effects with increased fatality rates. Currently, there are no FDA approved PIM kinase inhibitors available for specific cancer target therapies, despite the growing need and high demand research interests. It is widely …


Development And Flight Of Stratospheric Missions For Hard X-Ray Polarimetry And Hard X-Ray Spectroscopy, Ephraim Gau Apr 2026

Development And Flight Of Stratospheric Missions For Hard X-Ray Polarimetry And Hard X-Ray Spectroscopy, Ephraim Gau

Arts & Sciences Graduate Student Theses and Dissertations

The recent launches of the {\it Imaging X-ray Polarimetry Explorer} ({\it IXPE}\,) and {\it XRISM} have provided significant advances to the realms of polarization and high-resolution spectroscopy in X-ray astrophysics. However, both of these satellite missions conduct measurements in the soft X-rays, below 10 keV. To obtain a complete picture of any astrophysical source, we must extend these capabilities to the hard X-rays, above 10 keV, as well. Thus, in my graduate work, I have directed my efforts in these two regimes: measuring the polarization of hard X-rays with {\it XL-Calibur}, and improving the energy resolution of hard X-ray telescopes …


Detection Of The Presence And Growth Of E. Coli Bacteria In A Droplet-Based Microfluidic System Using Laser Induced Fluorescence, Oshira Peiris Apr 2026

Detection Of The Presence And Growth Of E. Coli Bacteria In A Droplet-Based Microfluidic System Using Laser Induced Fluorescence, Oshira Peiris

Theses and Dissertations

Antimicrobial resistance is a biomedical event, wherein an infectious microbe becomes non-responsive to the dosage of a particular antibiotic due to previous overuse or overexposure. Currently, agar plate disc diffusion is used as the gold standard for detecting antimicrobial resistance. The possibility of miniaturizing and speeding up detection techniques for antimicrobial resistance is investigated in this thesis. Microfabrication techniques were used in developing two droplet microfluidic systems interfaced with laser induced fluorescence detection. Microfluidic devices were manufactured with different droplet generating geometries using poly-dimethyl siloxane, soft lithography and hydrophobic surface treatment. The microfluidic devices were tested for droplet quality using …


Revised Draft Final Butte Priority Soils Operable Unit (Bpsou) Unreclaimed (Ur) Sites New And Mahoney (Ur-23) Construction Completion Report (Ccr), Pioneer Technical Services, Inc. Apr 2026

Revised Draft Final Butte Priority Soils Operable Unit (Bpsou) Unreclaimed (Ur) Sites New And Mahoney (Ur-23) Construction Completion Report (Ccr), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Model Unification: A Systematic Approach For The Cluster Expansion, Kolten Barfuss Apr 2026

Model Unification: A Systematic Approach For The Cluster Expansion, Kolten Barfuss

Theses and Dissertations

A systematic approach for model unification of cluster expansion models is developed and demonstrated. The method builds on previous work with the Manifold Boundary Approximation Method (MBAM) to identify supremal models. The work is motivated by the exercise of unifying cluster expansion models – characterized by Π matrices – for two binary alloys that share one atomic species to form a model for the ternary alloy. The result is the Supremal Π Algorithm, a systematic unification algorithm that relies on an MBAM-informed understanding of models and on the singular value decomposition. The algorithm yields ΠΛ, a Π matrix for the …


Revised Draft Final Butte Priority Soils Operable Unit (Bpsou) Unreclaimed (Ur) Sites New And Mahoney (Ur-23) Construction Completion Report (Ccr), Pioneer Technical Services, Inc. Apr 2026

Revised Draft Final Butte Priority Soils Operable Unit (Bpsou) Unreclaimed (Ur) Sites New And Mahoney (Ur-23) Construction Completion Report (Ccr), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


A Masked-Perturbation Model For Destabilization Security Games In Feedback Systems, Gabriel Michael Perry Apr 2026

A Masked-Perturbation Model For Destabilization Security Games In Feedback Systems, Gabriel Michael Perry

Theses and Dissertations

In this thesis, we present a mathematical formulation for increasing cyberphysical system security. This model allows a system administrator to use assumptions about exposed signals to derive defense strategies meant to mitigate the system's vulnerability to feedback perturbation attacks. We begin with a survey of game theory with the goal of building the concepts of resource and security games. We then introduce our model, which is a security game; targets in this game are exposed signals in the model map of the system, and resources are perturbed or introduced dynamical relationships between these signals. This formulation, called the masked-perturbation model, …


Theoretical Expressivity Of Self-Attention As A Model Of Binary Sequence-To-Sequence Functions And Other Explorations, Dustin Angerhofer Apr 2026

Theoretical Expressivity Of Self-Attention As A Model Of Binary Sequence-To-Sequence Functions And Other Explorations, Dustin Angerhofer

Theses and Dissertations

The self-attention mechanism lies at the heart of modern sequential modeling with deep neural networks, especially in the context of Large Language Models (LLMs). The basic role of self-attention is to capture pairwise interactions between tokens in a sequence. This allows token embeddings to be endowed with context-dependent information before further processing. Despite its widespread use, our theoretical understanding of self-attention is still nascent. In this work, we examine self-attention as a model of binary sequence-to-sequence (seq2seq) functions, which is the simplest non-trivial case to analyze. We find, using VC dimension and the Sauer-Shelah lemma, that in the limit of …


Some Closure On The Relation Between Cfg And Peg, Nathan J. Bulloch Apr 2026

Some Closure On The Relation Between Cfg And Peg, Nathan J. Bulloch

Theses and Dissertations

We work toward a practical, unified language formalism for structurally recursive languages by expressing the mathematical theories underlying context-free grammars with lookahead (CFGLA) in the Rocq theorem prover and leveraging CFGLA semantics to analyze interactions between between recursion and negative lookahead. We give examples of grammars with left-recursive negation cycles for the parsing expression grammar (PEG) variant due to Medeiros et al. and for the translation from PEG to CFGLA due to Miyazaki and Minamide. To study the interaction between left recursion and negative lookahead in a PEG context, we introduce FPEG, a left-recursive extension of PEG with Fitting semantics.


The Lookahead Transformer, Justin P. Olcott Apr 2026

The Lookahead Transformer, Justin P. Olcott

Theses and Dissertations

Large Language Models (LLMs) are transformer models that generate text autoregressively in two stages: prefill and decode. The prefill stage processes all input tokens in parallel and caches them into the KV cache. The decode stage uses the KV cache, processes a single token at a time, and is generally memory-bandwidth constrained. Each decode step generates a token probability distribution, samples from it, appends the token to the cache, and repeats. This left-to-right, one-at-a-time generation paradigm has proven effective for language modeling in many domains; however, it also has limitations such as token permanence, constant compute per token generation, constant …


Histopathology Image Classification Using Machine Learning, Mohammed H. Alali Apr 2026

Histopathology Image Classification Using Machine Learning, Mohammed H. Alali

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Histopathology image classification is a critical component of cancer diagnosis. However, the gigapixel scale of Whole-Slide Images (WSIs) and the high variability in tissue staining and scanner quality across medical centers present significant computational challenges. This dissertation proposes a comprehensive machine learning framework to address these challenges, bridging the gap between theoretical models and practical clinical deployment.

First, to manage the massive dimensionality and noise inherent in WSIs, this research develops a robust feature extraction methodology. The pipeline implements a stringent tile filtering technique to eliminate physical artifacts and resolve severe class imbalances. It integrates ConvNeXt alongside an attention-based pooling …


Cohomological Support Varieties Along Ring Maps, Ryan Watson Apr 2026

Cohomological Support Varieties Along Ring Maps, Ryan Watson

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Inspired by Quillen’s geometric approach to study group cohomology, Avramov introduced the theory of support varieties to study finite modules over local complete intersection rings. Geometric properties of the variety encode important homological information, and this theory has been a useful tool in studying complete intersection rings leading to many advances in local commutative algebra. By the work of several authors, this theory has now been expanded to encompass any noetherian local ring. Notably, Pollitz developed the theory of cohomological support varieties over Koszul complexes and used them to answer a question of Dwyer, Greenlees, and Iyengar regarding the structure …


Robust Thermodynamic Analysis Of Flexible Protein-Ligand Binding Using Statistical Mechanics, Mitchell Dulaney Apr 2026

Robust Thermodynamic Analysis Of Flexible Protein-Ligand Binding Using Statistical Mechanics, Mitchell Dulaney

Create@State

Understanding how proteins bind small molecules is essential for accurate computational modeling of biological systems. However, calculating binding free energy (delta G), enthalpy (delta H), and entropy (delta S) becomes unreliable when proteins are flexible, and ligands are between multiple binding positions. This motion causes traditional computational methods to produce inconsistent thermodynamic values.

A computational workflow was implemented that included docking to predict likely binding positions, molecular dynamics simulations to sample how the protein and ligand move over time, and statistical mechanics analysis to calculate thermodynamic quantities. A new theoretical framework was developed and implemented in a custom program to …


Ma(1) Or White Noise?, Orithea Regn, Ferebee Tunno Apr 2026

Ma(1) Or White Noise?, Orithea Regn, Ferebee Tunno

Create@State

This project provides an over of testing an MA(1) process confidence interval while keeping the margin of error to a minimum, even for small sample sizes.


Synthesizing Fluorescent 3,4-Dihydropyrimidin-2(1h)-Ones Using A One-Pot Synthesis Reaction, John R. Griggs Apr 2026

Synthesizing Fluorescent 3,4-Dihydropyrimidin-2(1h)-Ones Using A One-Pot Synthesis Reaction, John R. Griggs

Create@State

In medical and pharmaceutical practices, Biginelli (3,4-dihydropyrimidin-2(1H)-ones) products have a number of potential uses due to their anticancer and anti-inflammatory properties.  In addition, they are a possible treatment for acquired immunodeficiency syndrome (AIDS). These compounds can be further modified to exhibit fluorescent properties. However, before using them in medicinal studies, it is useful to establish a procedure that can easily be modified and is synthetically accessible to allow for further optimization. The experiment was performed using the Biginelli compounds as a substrate, along with a variety of aromatic aldehydes and acids. After obtaining the products and purifying them with vacuum …


Laser Ablation-Atomic Absorption Spectroscopy Of Yttrium Plasma, Dawn Gipson Apr 2026

Laser Ablation-Atomic Absorption Spectroscopy Of Yttrium Plasma, Dawn Gipson

Create@State

Laser ablation is a widely used sampling method for elemental chemical analysis. Laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively-coupled mass spectrometry (LA-ICP-MS) are the two most common implementations. Application of these techniques is found throughout the sciences, including analysis in archaeological settings, geology, and medical analysis of hard tissue such as teeth or bone. Many applications benefit from the microdestructive nature of the technique. However, the relationship between the laser-ablation crater and the analytical signal is poorly understood. Laser ablation-atomic absorption spectroscopy (LA-AAS) is used in our laboratory to determine the mass of material incorporated into the plasmas in …


Synthesis And Characterization Of Thiazole Derivatives As Potential Antitumor Agents, Kaylee Leddy Apr 2026

Synthesis And Characterization Of Thiazole Derivatives As Potential Antitumor Agents, Kaylee Leddy

Create@State

Melanoma is the 5th most common cancer in both men and women in the USA. It originates in melanocytes, which make the melanin pigment that gives skin its color. While treatable in early stages, melanoma becomes nearly incurable once metastasized. Thiazole derivatives have been recognized in many pharmaceutical classes including anticancer, antimicrobial, antimalarial, anti-tuberculosis, and diuretics. They have long been researched for their natural pharmacological properties and have shown potential to inhibit melanoma cell growth. In this study, catechol-substituted thiazole derivatives were synthesized using the Hantzsch-Thiazole synthesis. A total of 13 novel compounds were made using 2-chlorodihydroxyacetophenone with various catechol-substituted …


Understanding The Relationship Between Morphometric Indices Of The Eleven Point River And Sediment And Nutrient Transport, Karimot Shobowale, Jennifer Bouldin Apr 2026

Understanding The Relationship Between Morphometric Indices Of The Eleven Point River And Sediment And Nutrient Transport, Karimot Shobowale, Jennifer Bouldin

Create@State

Objective: To evaluate how watershed characteristics impact sediment transport and water quality parameters.


Spatial Computing With The Apple Vision Pro In Minimally Invasive Procedure Simulation: A Randomized Crossover Feasibility Study, Sydney Cooper, Aaron Kyle Jones, Rahul Anil Sheth, Koustav Pal, Bruno Odisio, Mark Blaylock, Shelita Kimble, Justin Bird, David Rice, Daniel Shoenthal, Emil Patel, Vipin Kamath, Sanjay Gupta, Jeffrey Siewerdsen, Joshua Kuban Apr 2026

Spatial Computing With The Apple Vision Pro In Minimally Invasive Procedure Simulation: A Randomized Crossover Feasibility Study, Sydney Cooper, Aaron Kyle Jones, Rahul Anil Sheth, Koustav Pal, Bruno Odisio, Mark Blaylock, Shelita Kimble, Justin Bird, David Rice, Daniel Shoenthal, Emil Patel, Vipin Kamath, Sanjay Gupta, Jeffrey Siewerdsen, Joshua Kuban

Advances in Cancer Education and Quality Improvement

Purpose: This study aimed to evaluate the feasibility of wearing the Apple Vision Pro (AVP), a mixed-reality headset that integrates augmented and virtual reality, while performing minimally invasive procedures. While studies have demonstrated that spatial computing technology can improve surgical precision and reduce the risks of surgical complications, to our knowledge, no studies have specifically addressed the impact of the AVP on task performance during simulated image-guided procedures.

Materials and Methods: Thirteen diagnostic and interventional radiology residents performed image-guided central venous catheter placement, thoracentesis, and paracentesis on simulation models. Each participant completed a non-timed practice followed by the procedures once …


Inc3vits Model: A Hybrid Architecture To Accelerate And Reduce Complexity For The Deepvariant Model For Variant Calling, Mustafa Al-Saffar, Sura Z. Al Rashid Apr 2026

Inc3vits Model: A Hybrid Architecture To Accelerate And Reduce Complexity For The Deepvariant Model For Variant Calling, Mustafa Al-Saffar, Sura Z. Al Rashid

Karbala International Journal of Modern Science

Deep learning has revolutionized genomic variant calling, yet the computational cost of current systems continues to limit scalability. We present a controlled efficiency study of DeepVariant-style pileup architectures under identical training and inference conditions, comparing architectural downsizing with a hybrid CNN–local attention design. Inc3ViTs pairs a streamlined InceptionV3 stem with a lightweight local attention head based on patch tokenization and windowed self-attention, enabling a direct comparison with a CNN-only reduced Inception baseline. Across whole-genome and whole-exome short-read datasets, Inc3ViTs reduces training time by ~40–50% and reduces inference runtime relative to the original DeepVariant. The CNN-only baseline indicates that most speedups …


Review On Optimization Of Simulation Modeling Strategies For Spacecraft Orbit Avoidance, Guozheng Li, Rui Wang, Shichao Fan, Xintong Cai, Xinyue Zhai Apr 2026

Review On Optimization Of Simulation Modeling Strategies For Spacecraft Orbit Avoidance, Guozheng Li, Rui Wang, Shichao Fan, Xintong Cai, Xinyue Zhai

Journal of System Simulation

Abstract: The number of on-orbit spacecraft increases exponentially; the space environment becomes more complex, and the collision risk of on-orbit spacecraft increases significantly. On-orbit safety is thus severely threatened, posing higher requirements for orbit avoidance methods. The costs and risks of space activities are extremely high, making simulation an effective method to solve complex problems of orbit avoidance. The modeling, solution, and simulation methods for the two core issues of spacecraft orbit avoidance, "collision avoidance" and "pursuit-evasion games", were systematically reviewed, and the existing shortcomings were analyzed. The applications of technologies such as deep reinforcement learning in promoting orbit avoidance …


Modelling Method Of Unmanned Vehicle Dynamics Based On Neural Network, Jun Wang, Min Liu, Xiaochuan Zhang, Yishan Ding, Juhui Feng, Ye Zhuang Apr 2026

Modelling Method Of Unmanned Vehicle Dynamics Based On Neural Network, Jun Wang, Min Liu, Xiaochuan Zhang, Yishan Ding, Juhui Feng, Ye Zhuang

Journal of System Simulation

Abstract: To address the challenges of high data acquisition costs of test data on dynamic characteristics between tires and soft terrain and low speed of numerical calculation for unmanned vehicles in complex terrestrial environments, a modeling method of unmanned vehicle dynamics based on a neural network was proposed. Tire-terrain contact dynamics models were built by using discrete element method (DEM) simulations for tire-terrain contact and experimental data, thereby creating a dataset of tire contact forces for various tire materials in terrestrial environments. The neural network was applied to regressively learn the dataset, and a nonlinear neural network tire model was …


Method For Testing And Evaluating Intelligence Level Of Virtual Forces Based On Operational Experiments, Dayong Liu, Zhiming Dong, Weidong Zhang, Wenjun Zhang, Jiancheng Gao Apr 2026

Method For Testing And Evaluating Intelligence Level Of Virtual Forces Based On Operational Experiments, Dayong Liu, Zhiming Dong, Weidong Zhang, Wenjun Zhang, Jiancheng Gao

Journal of System Simulation

Abstract: The intelligence level of virtual forces is a key factor affecting the credibility and effectiveness of tactical confrontation simulations. To address the current lack of a testing and evaluation system, a method for testing and evaluating the intelligence level of virtual forces based on operational experiments is proposed. Guided by operational experiment theory, the method stimulates the intelligent behavior of virtual forces by constructing dynamic confrontation environments, and collects, calculates, analyzes, and evaluates their intelligence performance data according to a systematic process. The overall architecture, logical functional modules, and basic evaluation process of the method are designed. A "4M" …


Swosu Research And Scholarly Activity Fair 2026, Swosu Office Of Sponsored Programs Apr 2026

Swosu Research And Scholarly Activity Fair 2026, Swosu Office Of Sponsored Programs

SWOSU Research and Scholarly Activity Fair Programs

On behalf of the University Research and Scholarly Activity Committee (URSAC) and the Office of Sponsored Programs (OSP) at Southwestern Oklahoma State University, we are pleased to welcome you to the Thirty-Fourth SWOSU Research and Scholarly Activity Fair.


Signatures Of Vapor Evolution In Turbulent Convection Cells Recorded By K And Rb Isotopes In Chicxulub Impact Spherules, Courtney Jean Rundhaug, Martin Schiller, Martin Bizzarro, Zhengbin Deng, Hermann Dario Bermúdez Apr 2026

Signatures Of Vapor Evolution In Turbulent Convection Cells Recorded By K And Rb Isotopes In Chicxulub Impact Spherules, Courtney Jean Rundhaug, Martin Schiller, Martin Bizzarro, Zhengbin Deng, Hermann Dario Bermúdez

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Cretaceous–Paleogene boundary (∼66 Ma) records the Chicxulub asteroid impact, a pivotal event in Earth's history that affected much of the Earth's surface. While products of this impact have been widely studied, the thermodynamics of the plume and formation mechanisms of certain impact materials remain unclear. This study investigates conditions within the intermediate fraction of the Chicxulub impact plume (pyrocloud) using K and Rb isotope signatures of Gorgonilla Island impact spherules with published δ25Mg data to trace evaporation and condensation processes during ejecta dispersion. The δ41K and δ87Rb signatures vary from −1.18 ± 0.04‰ to 0.43 ± 0.09‰ and − …


The Impact Of State And Federal Policies On Academic Researchers: Findings From A National Survey, Dylan Ruediger, Chelsea Mccracken, Jonathan Barefield Apr 2026

The Impact Of State And Federal Policies On Academic Researchers: Findings From A National Survey, Dylan Ruediger, Chelsea Mccracken, Jonathan Barefield

Copyright, Fair Use, Scholarly Communication, etc.

Key findings

● State and federal policies targeting divisive concepts or DEI are shaping research agendas at scale and across disciplines. Twenty percent of all respondents, and 29 percent of researchers working in states with divisive concepts or similar laws, reported having avoided certain research topics because of state laws and policies.

● Eight percent of respondents representing a wide range of disciplines reported having had a federal grant cancelled in 2025.

● Eleven percent of respondents reported that federal and state policies restricting research activities are compelling them to seek employment out of state, to leave the academy, or …