Physics Commons^™

Neurophysiology And Endocrine Responses To Hunger And Satiety Mechanisms: The Brain-Gut Crosstalk, Nour Shakir Rezaieg, Muthanna M. Awad

Karbala International Journal of Modern Science

Background: Obesity is a main public health problem which substantially increases the risk of many diseases. The complex neural circuitry controls energy homeostasis and food consumption by the incorporation of hormonal and neural signals. Circulating hormones, in specific the gut hormones, have been found to be very important in appetite regulation. These hormones transfer energy situation signs to the brain throughout three principle paths: the circulation system, activation of the vagus nerve, and direct modification of main brain regions such as the hypothalamus and brainstem. The control of food eating is not exclusively dependent on the homeostatic processes, rather it …

A Novel Chaotic Dna-Based Image Cryptosystem Leveraging Euclidean Division, Dynamic Josephus Traversal, And Reservoir Computing, Ahmed Kareem Shibeeb, Salah Albermany, Sadiq A. Mehdi

Karbala International Journal of Modern Science

This study presents a new chaotic DNA-based image cryptosystem that combines Euclidean division, dynamic Josephus traversal (DJT), and reservoir computing to address the weaknesses of current methods. Old chaotic DNA cryptosystems usually have problems such as using the same keys for different messages, simple DNA processes, and being vulnerable to attacks where the attacker can choose the input or try many options. The cryptosystem in this study uses a 7D hyperchaotic system that starts with keys created from SHA-512 hashes to produce changing keystreams based on the plaintext, making it very strong against such attacks. The proposed cryptosystem uses a …

Ideal Mathematical Pendulum: Examples Of Physics Problem Conditions Expressed Primarily Through Diagrams, Vasiliy Znamenskiy

Open Educational Resources

This article explores an innovative approach to physics education centered on the formulation of problems using visual diagrams with minimal textual description. Departing from traditional word-heavy methods, the proposed technique leverages schematic drawings as the primary mode of problem presentation. This visual-first strategy facilitates intuitive understanding, promotes spatial reasoning, and supports the development of abstract thinking in students. The method is especially effective in diverse classrooms where language barriers may hinder comprehension. By engaging learners through image-based tasks, the approach reduces cognitive load, fosters independent discovery of physical principles, and enhances overall conceptual clarity. Examples from mechanics and oscillations illustrate …

Investigation Of Subcellular Damage And Long-Term Non-Cancerous Cardiovascular Effects Following Whole-Body Photon Irradiation, Nousha Afshari

LSU Doctoral Dissertations

Current radiobiological models focus primarily on nuclear DNA damage and fail to fully explain radiation-induced noncancerous health effects. This dissertation investigates whether non-nuclear subcellular structures contribute to radiation-induced biological damage through experimental biomarker analysis and computational microdosimetry. The central hypothesis posits that whole-body photon irradiation results in subcellular non-nuclear damage, specifically increased circulating mitochondrial DNA concentrations, that correlates with radiation dose and long-term noncancerous effects such as cardiovascular disease.

Specific Aim 1 measured mitochondrial and nuclear DNA concentrations in banked blood samples from 72 Chinese rhesus macaques that previously received whole-body photon irradiation ($0-10$ Gy) from Cobalt-60 or LINAC sources. …

Large Bandgap Observed On The Surfaces Of Euzn2As2 Single Crystals, Dejia Kong, Siavash Karbasizadeh, Ganesh Narasimha, Paras Regmi, Chenggang Tao, Chenggang Tao, Sai Mu, Rama Vasudevan, Ian Harrison, Rongying Jin, Zheng Gai

Faculty Publications

EuZn₂As₂ (M = Zn, Cd, In, Sn etc.) is an excellent material system for studying magnetism-tuned topological properties. However, discrepancies exist between experimental data and theoretical calculations regarding the bulk and surface bandgaps. In this work, cleaved EuZn₂As₂ crystals are studied using scanning tunneling microscopy/spectroscopy and density functional theory calculations. Triangular-shaped defect-induced modifications in the local density of states help distinguish between Eu-terminated and AsZn-terminated surfaces. While large bandgaps ( ~1.5 eV at 77 K) are observed on both pristine surfaces, the bandgap size is found to be highly sensitive to local heterogeneity, tending …

A Wide-Field Map Of Ultracompact Dwarfs In The Coma Cluster, Richard T. Pomeroy, Juan P. Madrid, Conor R. O’Neill, Alexander T. Gagliano

Physics & Astronomy Faculty Publications

A data set of 23,351 globular clusters (GCs) and ultracompact dwarfs (UCDs) in the Coma cluster of galaxies was built using Hubble Space Telescope Advanced Camera for Surveys data. Based on the standard magnitude cut of MV ≤ −11, a total of 523 UCD candidates are found within this data set of compact stellar systems (CSS). From a color–magnitude diagram analysis built using this catalog, we find a clear mass–magnitude relation extending marginally into the UCD parameter space. The luminosity function defined by this data set shows an excess of sources at bright magnitudes, suggesting a bimodal formation scenario …

Orbital Modulation Of Gamma Rays Up To 100 Tev From Ls 5039, R. Alfaro, M. Araya, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, R. Babu, P. Bangale, E. Belmont-Moreno, A. Bernal, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño De León, D. Depaoli, P. Desiati, N. Di Lalla, R. Diaz Hernandez, B. L. Dingus, M. A. Duvernois, K. Engel, T. Ergin, C. Espinoza, K. L. Fan, K. Fang, J. A. Garcia-Gonzalez, H. Goksu, A. Gonzalez Munoz, J. A. Gonzalez, M. M. Gonzalez, J. A. Goodman, S. Groetsch, J. P. Harding, S. Hernandez-Cadena, I. Herzog, J. Hinton, D. Huang, F. Hueyotl-Zahuantitla, P. Huntemeyer, S. Kaufmann, D. Kieda, A. Lara, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Morales-Soto, E. Moreno, M. Mustafa, M. Najafi, L. Nellen, M. U. Nisa, N. Omodei, E. Ponce, Y. Perez Araujo, E. G. Perez-Perez, C. D. Rho, A. Rodriguez Parra, D. Rosa-Gonzalez, M. Roth, H. Salazar, D. Salazar-Gallegos, A. Sandoval, M. Schneider, G. Schwefer, J. Serna-Franco, A. J. Smith, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, E. Varcla, Xiaojie Wang, Z. Wang, I. J. Watson, H. Wu, S. Yu, S. Yun-Carcamo, H. Zhou, C. De Leon

Physics Faculty Research & Creative Works

Gamma-ray binaries are luminous in gamma rays, composed of a compact object orbiting a massive companion star. The interaction between these two objects can drive relativistic outflows, either jets or winds, in which particles can be accelerated to energies reaching hundreds of teraelectronvolts (TeV). However, it is still debated where and under which physical conditions particles are accelerated in these objects and ultimately whether protons can be accelerated up to PeV energies. Among the well-known gamma-ray binaries, LS 5039 is a high-mass X-ray binary with an orbital period of 3.9 days that has been observed up to TeV energies by …

An Analysis Of Fast Radio Bursts, Alessandro Tripoli

Discovery Day (formerly Post & Beyond)

Fast radio bursts (FRBs) were recently discovered in 2007 and have been a mystery ever since. The purpose of this study is to analyze progenitor models of possible origin. Despite their large energies, these bursts appear only in the radio band of the electromagnetic spectrum. Out of the 33 measured FRBs, only one has been observed to repeat (FRB 121101). In this work the significance of important properties such as the dispersion measure, Faraday rotation, and magnetic fields is discussed. The most persuasive progenitor models including binary neutron star mergers, soft gamma ray repeaters (SGRs), Gamma ray bursts (GRBs), merging …

Carbon Dioxide Conversion To Value-Added Products Over Fe Based Heterogeneous Catalysts, Alessandro Tripoli

Discovery Day (formerly Post & Beyond)

Carbon dioxide (CO₂) is a well-known greenhouse gas, which traps heat in the atmosphere causing global warming. The purpose of this study is to develop novel iron (Fe) based catalysts to convert CO₂ to value added chemicals such as carbon monoxide (CO), methane, ethylene, ethane and fuels. In this work, the heterogeneous Fe-based catalysts were synthesized via a wetness incipient impregnation method. The synthesized catalysts were tested for CO₂ hydrogenation through a flow bed reactor with controlled CO₂ and hydrogen (H₂) flow rate and on-line gas chromatography analysis to determine the catalyst performance …

Development Of Iron Based Heterogeneous Catalysts For Methane Conversion, Alessandro Tripoli

Discovery Day (formerly Post & Beyond)

Methane, main component of natural gas, is an abundant, inexpensive, and easily accessible resource due to the recent discoveries of natural gas reservoir in US. The purpose of this work is to convert methane to value-added product such as methanol. Methanol can be directly used as a liquid fuel and as a raw material for other industrial process. In this work, a series of novel iron-based catalysts supported on silicon carbide and zirconium oxide were designed and synthesized via a wetness incipient impregnation method. The synthesized catalysts were tested for CH₄ oxidation with O₂ through a flow bed …

Electroexcitation Of Nucleon Resonances And Emergence Of Hadron Mass, Patrick Achenbach, Daniel S. Carman, Ralf Gothe, Kyungseon Joo, Victor I. Mokeev, Craig D. Roberts

Faculty Publications

Developing an understanding of phenomena driven by the emergence of hadron mass (EHM) is one of the most challenging problems in the Standard Model. This discussion focuses on the impact of results on nucleon resonance (N*) electroexcitation amplitudes (or γ_vpN*) obtained from experiments during the 6 GeV era in Hall B at Jefferson Lab on understanding EHM. Analyzed using continuum Schwinger function methods (CSMs), these results have revealed new pathways for the elucidation of EHM. A good description of the Δ (1232) 3/2⁺, N (1440) 1/2⁺, and Δ (1600) 3/2^{+ …}

Data Supporting The Paper "Enhancing Turbulent Mixing And Microphysical Uniformity In A Tall Convection-Cloud Chamber Through Idealized Heterogeneity Of Boundaries", Lois Thomas, Fan Yang, Aaron Wang, Mikhail Ovchinnikov, Kyle G. Pressel, Raymond Shaw

Michigan Tech Research Data

A large convection cloud chamber has been proposed for exploring aerosol–cloud–drizzle interactions under well-controlled turbulent conditions. Recent theoretical and numerical studies suggest that a convection cloud chamber with two heated and two cooled sidewalls can significantly enhance the liquid water content and thus benefit drizzle initiation. However, a chamber with such a sidewall configuration develops stable stratification and extremely weak turbulence therein. In this study, we conduct large-eddy simulations of a tall convection chamber with five different sidewall configurations consisting of alternating warm and cold patches. For each configuration, the total surface area of warm patches equals that of cold …

Current Continuity In Auroral System Science, Jules Van Irsel

Dartmouth College Ph.D Dissertations

The Earth relies on the Sun's energy, but at times this energy can be overwhelming; the Sun expels plasma which, were it not for our humble magnetic field, would erode our atmosphere (Mars, c. 4 Ga). The protective interaction Earth has with the solar wind results in spectacular auroral displays---one such auroral form is discussed in this thesis: quiet discrete auroral arcs.

Such arcs have long been studied; they are abundant, have usable symmetries, and they can predict magnetic substorms that wreak havoc in our magnetosphere. The auroral emissions, albeit beautiful, are however only the visible end of a self-consistent …

Investigating Long-Lasting Meteor Train Phenomena In Optical And Radio Regimes, Logan E. Cordonnier

Physics & Astronomy ETDs

Throughout history, meteors have been regarded as fascinating and portentous events, with bygone astronomers diligently recording their occurrence. The research presented herein continues in this tradition, using modern instruments, software, and data reduction techniques to study long-lasting meteor trail phenomena, specifically in the optical (persistent trains; PTs) and radio (meteor radio afterglows; MRAs) regimes. The overarching goal was to investigate the similarities between these phenomena, which began with the creation of a PT catalog. Many of the prior assumptions about the nature of PTs were found to be unsubstantiated, and several new behaviors were uncovered. This includes the discovery of …

Dr. Steven Iona Faculty Spotlight, Rachel Jaeger

DU Undergraduate Research Journal Archive

An interview with Dr. Steven Iona of the University of Denver's Department of Physics and Astronomy.

Du Undergraduate Showcase Abstracts: Research, Scholarship, And Creative Works, Kabe Aberle, Nadia Kako, Kateri Mcrae, Brooke Agulnek, Sky Palmon, Yasmine Ramirez, Francisca Aguirre Beltran, Ashley Juarez, Bridget Kim, Tessa Appel, Sterling Kerr, Spencer Ingley, Gabe Meyer, Robin Tinghitella, Dale Broder, Lily Baeza, Chloe Beers, Julia Coakley, Whitney Kelsey, Sydney Gainforth, Gabi Wing, Audrey Martin, Aaliyah Amore Berry, Brooke Watley, Kiruthika Venkatesan, Rachel Bienstock, Annabella Brotherston, Madison Bryant, Mia Burgener, Emma P. Lieb, Rachel A. Johnson, Jennifer L. Hoffman, Kania Campbell, Kiena Campbell, Courtney Cassidy, Sage Krzyzkowski, Maddox Jones, Skylar Abookire, Luke Hawkins, Sunnah Yoon, Andrea Chu, Yan Qin, Nyah Cubbison, Brian Gearity, Daniel Mcintosh, Mariely Cruz, Edward Garrido, Grady Dionne, Nicole Doris, Lyndsie Salvagio, Ann-Charlotte Granholm-Bentley, Anna Dymov, Hannah Eckert, Gabrielle Welsh, Erica Larson, Charlie Ernst, Anna Zhou, Sarah Watamura, Larissa Fedorovich-Klein, Georgie Fields, Kimberly A. Guevara, Aven Mccall, Ben Peltier, Feruz Yahia, Patrick Flores, Jadyn Floyd, Sophia Forcier, J. Von R. Monteza, Peter Sokol-Hessner, Gwendolyn Geiger, Scott Nichols, Camryn Gunter, Kendal Hengst, Charlie Bednarz, Issy Garside, Addison Baker, Rachel Mina, Brooke Hermanson, Amanda Klingler, William Highfill, Sydney Jaques, Kerstin Lewey, Allison Grossery, Daniel Linseman, Ethan Lim, Jagger Livengood, Owen Mantelli, Gabby Pappas, Abby Mcdonald, Madeleine Dierking, Eve Miller, Emma Loeber, Anna Marlow, Michael Kerwin, Ella Mathews, Hillary Hamann, Khadija Mohamed, Vivian Nguyen, Gabri Notov, Ifunayachi Ogbonna-Ukuku, Sunil Kumar, Charles Baysah, Sarah Olson, Don Sullivan, Anna Paradiso, Jay Parrish, Mira Pronobis, Alisha Pravasi, Kerstin Haring, Diego Ramirez, Christopher Reardon, Juliana Ramirez, Casey Doherty, Ella Kestner, Teagan Weindel, Cate Billings, Pablo Torre-Walter, Lucy Rand, Samantha Reynolds, Mark Siemens, Khadeeja Rashid, Laine Satterlee, Piper Heilbronner, Lily Pound, Ben Whitehurst, Anna Respet, Lizzie Lesoing, Sydney Hertel, Aya Saad-Masri, Brooke Ballenger, Max Proske, Hannah Rosenberg, Ellia Nakahara, Sophia Espinoza, Ivan Woolhouse, Simon Ruland, Gorkem Er, Timothy Sweeny, Melaku Saketa, Michela Schenk, Maren Lynch, Madi Hamm, Grace Schroeder, Michelle Rozenman, Rana Seif, Jackson Hall, Marisela Simental, Daniel Paredes, Aaron Mena, Preston Spaan, Evelyn Stovin, David Andrew Swartz, Anh Tran, Daniel Pittman, Luke Farchione, Emily Boyer, Ukari Verner, Lacey Conrad, Jonathan Velotta, James Weiner, Jagger Gossett, Noah Sherry, Sam Proud, Ben Block, Avi Narayana, Zoey Weiss, Alyssa Wilson, Gabrielle Walsh, David Zonana, Keely Wright, Kena Riveria, Lillybelle Deer, Jena Doom, Elysia Davis, Isabelle Yaremenko, Caitlyn Young

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Research Showcase.

Positive And Negative Parity States Of 226-236th Isotopes, Ali A. Mezban, Falih H. Al-Khudair

Karbala International Journal of Modern Science

The level scheme of the ^226-236Th nuclei is analyzed using the Interacting Boson Model (IBM-1). The ground state band (g. s.-band), beta band (β-band), gamma band (γ-band) have been described in the sd model space. To calculate the negative parity energy levels, the model space is extended to sdf by adding the f-boson (L=3). A sequence of states in energy bands up to 3.5 MeV has been obtained. The decay of negative states below 1 MeV built on an octupole vibration modes is investigated. The transition probabilities in-band and inter-band are calculated using the wave function of the …

Studying Effect Of Temperature On Photovoltaic Characteristics Of Photovoltaic Modules Based On Cigs Solar Cells, Farrux Anvar O‘G‘Li Akbarov, Anvar Akbarovich Alimov

Technical science and innovation

The article presents the experimental results of the temperature dependence of the load current-voltage characteristics of a solar photovoltaic (PV) module based on a polycrystalline semiconductor binary compound Cu(In,Ga)Se₂ under normal sunlight P_rad=800±5 W/m², in a temperature range of (32÷60) ^оС. It was found that the temperature dependence of the photocurrent has two slopes, which is explained by a change in the generation-recombination mechanism. An increase in the short-circuit current with an increase in the temperature of the photovoltaic module is explained by an increase in the drift length of minority charge carriers, due …

Implementing A Sustainability Approach By Converting Plastic Bottle Waste From A Mischievous Substance To A Beneficial Material By Means Of Zero Residue Level Concept, Younus Mohammed Abed, Fatima Allawi, Shahad Mudhafar Ali, Salem Jawad Alhamd, Thekra Atta Ibrahim, Mohammed Nsaif Abbas

Karbala International Journal of Modern Science

Plastic waste represents a serious environmental and health hazard due to its non-biodegradability and toxic leachates. This study investigates the potential conversion of plastic waste into a sustainable raw material for producing a useful substance. This investigation focuses on repurposing PET beverage bottles—a major contributor to microplastic pollution—into high-value activated carbon (AC) for water treatment, aligning with circular economy principles. The chemical preparation method for AC using phosphoric acid as an activating agent was evaluated. Results demonstrated the successful conversion of 68% of plastic waste into AC under the following conditions: pyrolysis temperature of 700°C, pyrolysis time of 7 hours, …

3d Solid Models, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

3D solid models for model vehicles, target panels, objects, and the desert terrain model in STL file format.

Ground Truth Images, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

Laboratory and scenario ground truth images for the Model Desert Terrain Monochromatic DoT dataset.

Polarimetric Data: Scenario 01, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

Polarimetric data Scenario 01 collected within the Automated Remote Sensing Solar Simulation Lab at the University of Dayton. The data were collected using a visible monochromatic division-of-time imaging polarimeter. The dataset is parameterized across different sensor, scene, and illumination geometries that mimic outdoor solar irradiance conditions.

Dataset Description, Bradley M. Ratliff

Model Desert Terrain Monochromatic DoT Dataset

Polarimetric dataset containing data collected within the Automated Remote Sensing Solar Simulation Lab at the University of Dayton. The data were collected using a visible monochromatic division-of-time imaging polarimeter. A model desert terrain model was constructed and imaged for eight different scenarios consisting of different model panel and vehicle targets. The dataset is parameterized across different sensor, scene, and illumination geometries that mimic outdoor solar irradiance conditions.

Search For Extremely-High-Energy Neutrinos And First Constraints On The Ultrahigh-Energy Cosmic-Ray Proton Fraction With Icecube, Karen Andeen

Physics Faculty Research and Publications

We present a search for the diffuse extremely-high-energy neutrino flux using 12.6 years of IceCube data. The nonobservation of neutrinos with energies well above 10 PeV constrains the all-flavor neutrino flux at 1018  eV to a level of 𝐸2⁢Φ𝜈𝑒+𝜈𝜇+𝜈𝜏≃10−8  GeV cm−2 s−1 sr−1, the most stringent limit to date. Using these data, we constrain the proton fraction of ultrahigh-energy cosmic rays (UHECRs) above ≃30  EeV to be  ≲70% (at 90% CL) if the cosmological evolution of the sources is comparable to or stronger than the star formation rate. This is the first result to disfavor the “proton-only” hypothesis for UHECR …

Two Dimensional Van Der Waals Magnet, Cheongheon Lee

Theses and Dissertations

Conventional charge-based memory has reached its limits in improving energy efficiency while scaling down size. Consequently, memory utilizing 2D magnetic materials has emerged as an alternative. 2D Van der Waals (VdW) magnets are ultrathin magnets with unique properties that make them optimal for this purpose. Utilizing the weak interlayer coupling via VdW interaction has enhanced the possibility of integrating diverse materials to create heterostructures. The integration of spintronics requires not only stable magnetization but also an effective switching mechanism. Various external influences have been experimentally tested, such as the proximity effect, external magnetic field, gate voltage, and temperature dependence. This …

The Role Of Symmetries In Atomic, Electromagnetic, And Particle Physics, Joshua Martin O'Connor

Theses and Dissertations

Symmetries in atomic, electromagnetic, and weak interaction physics are explored to understand symmetry-breaking extensions of the Standard Model of particle physics. Lorentz-violating field theories are extremely interesting theoretically, since they possess many new features that are absent in Lorentz-invariant models. We outline the formalism and experimental status of the Lorentz- and CPT-violating Standard Model Extension, in both the classical and quantum regimes. Processes such as vacuum Cerenkov radiation, which are kinematically forbidden when Lorentz symmetry is exact may become allowed when this symmetry is weakly broken. Particle decays, such as pion and kaon decays, although allowed in Lorentz-invariant theories, are …

Exploring Subfield Interest Development In Undergraduate Physics Students Through Social Cognitive Career Theory, Dina Zohrabi Alaee, Benjamin M. Zwickl

Physics and Engineering Science

This study investigates how undergraduate physics majors develop an interest in specific subfields. We examine interest formation through the lens of social cognitive career theory (SCCT) using four SCCT constructs: learning experiences, self-efficacy, outcome expectations, and proximal environmental influences. We conducted 27 interviews with physics majors across multiple years of study between 2020 and 2022. Our first research question used SCCT constructs to provide detailed insights into factors affecting interest formation in various subfields of physics. We identified many factors that positively impacted students’ interests, such as positive learning experiences (e.g., coursework, experimental projects, extracurricular clubs, and self-directed learning), high …

Crosssections, Summer 2025, University Of Northern Iowa. Department Of Physics.

CrossSections

Contents:

A Message from the Department Head, Dr. Paul Shand --- 1
Department Happenings --- 3
Faculty Profile - Takeshi Yasuda --- 7
Student Profile - Brandon Schmidt --- 8
Student Research --- 9
Student Focus --- 10
Physics Education --- 13
Alumni Profile - Roger Burkhart --- 14
Alumni News - Sterling Hartman --- 16
New Physics --- 17

Red Forest, Lucas Shilts

Senior Project

Sustaining large numbers of astronauts on Mars will require greenhouses capable of supplementing astronaut dietary needs. Lower solar irradiation and high levels of ionizing radiation on the Martian surface complicate the growth of crops on the red planet. Crops on Mars must be protected from radiation sources while still receiving sufficient illumination to grow. This research seeks to develop a Martian greenhouse illumination and heating design capable of efficiently providing plants the illumination and warmth needed while protecting them from the Martian radiation environment. This research explores a design for a direct-light subsurface Martian greenhouse which employs sun-tracking mirrors, vertical …

Learn, Sleep, Remember, Repeat, Charlie Martinez, Christian Fink

Physics Student Scholarship

My research focused on using computational methods to study the effect of sleep on memory. There are many simplifications that we used to break down this hefty question, but two are essential to understand: (1) we modeled a simple network (connection diagram included in poster) that comprised of only about 800 neurons (for reference the human brain contains about 80 billion neurons) and represented the connection between two brain regions the thalamus and the cortex, and (2) we modeled memory as a simple learning rule that strengthened connections between neurons that fired in sequence and weakened connections that pointed in …