Physical Sciences and Mathematics Commons^™

Why Core Curriculum? Why Art And Nature Enhance Creativity? A Mathematical Explanation, Olga Kosheleva, Vladik Kreinovich, Christian Servin

Departmental Technical Reports (CS)

Teaching is not easy. One of the main reasons why it is not easy is that the existing descriptions of the teaching process are not very precise -- and thus, we cannot use the usual optimization techniques, techniques which require a precise model of the corresponding phenomenon. It is therefore desirable to come up with a precise description of the learning process. To come up with such a description, we notice that on the set of all possible states of learning, there is a natural order s ≤ s' meaning that we can bring the student from the state s …

Why Aspirational Goals: Geometric Explanation, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Business gurus recommend that an organization should have, in addition to clearly described realistic goals, also additional aspirational goals -- goals for which we may not have resources and which most probably will not be reached at all. At first glance, adding such a vague goal cannot lead to a drastic change in how the company operates, but surprisingly, for many companies, the mere presence of such aspirational goals boosts the company's performance. In this paper, we show that a simple geometric model of this situation can explain the unexpected success of aspirational goals.

Why Pre-Teaching: A Geometric Explanation, Olga Kosheleva, Vladik Kreinovich, Christian Servin

Departmental Technical Reports (CS)

Traditionally, subjects are taught in sequential order: e.g., first, students study algebra, then they use the knowledge of algebra to study the basis ideas of calculus. In this traditional scheme, teachers usually do not explain any calculus ideas before students are ready – since they believe that this would only confuse students. However, lately, empirical evidence has shows that, contrary to this common belief, pre-teaching – when students get a brief introduction to the forthcoming new topic before this topic starts – helps students learn. In this paper, we provide a geometric explanation for this unexpected empirical phenomenon.

How To Describe Relative Approximation Error? A New Justification For Gustafson's Logarithmic Expression, Martine Ceberio, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

How can we describe relative approximation error? When the value b approximate a value a, the usual description of this error is the ratio |b − a|/|a|. The problem with this approach is that, contrary to our intuition, we get different numbers gauging how well a approximates b and how well b approximates a. To avoid this problem, John Gustafson proposed to use the logarithmic measure |ln(b/a)|. In this paper, we show that this is, in effect, the only regular scale-invariant way to describe the relative approximation error.

Video Or Text? Bullets Or No Bullets? Why Not Both?, Olga Kosheleva, Vladik Kreinovich, Christian Servin

Departmental Technical Reports (CS)

Some students – which are, in terms of pop-psychology – more left-brain – prefer linear exposition, others – more right-brain ones – prefer 2-D images and texts with visual emphasis (e.g., with bullets). At present, instructors try to find a middle grounds between these two audiences, but why not prepare each material in two ways, aimed at both audiences?

Paths Of Coexistence: Spatially Predicting Acceptance Of Grizzly Bears Along Key Movement Corridors, Abigail H. Sage, Vicken Hillis, Rose A. Graves, Morey Burnham, Neil H. Carter

Human-Environment Systems Research Center Faculty Publications and Presentations

Landscape connectivity is important for conserving wildlife in spaces shared with humans. Yet, differences in human attitudes and behaviors within movement corridors can lead to spatial variation in the risks humans pose to wildlife. Mapping the spatial pattern of attitudes toward wildlife provides a useful tool for measuring this variation and promoting connectivity. We surveyed ranchers (n = 505) in the High Divide region in eastern Idaho and western Montana (United States) about their attitudes toward grizzly bears (Ursus arctos) – a species that can pose risks to livestock and human safety. We assessed spatial variation in …

Sustainability Obligations And Liabilities For The Company Director, Richard Allen, Michael Tang, Jan Tan, Gautam Mukharya

Perspectives@SMU

SGX now requires its listees to issue a sustainability report. Why is this happening? And what do directors need to know?

Network-Based Pharmacology Study Reveals Protein Targets For Medical Benefits And Harms Of Cannabinoids In Humans, Xingyu Li, Amit Madhukar Kudke, Felix Joseph Nepveux V, Yan Xu

Chemistry Faculty Publications

This network-based pharmacology study intends to uncover the underlying mechanisms of cannabis leading to a therapeutic benefit and the pathogenesis for a wide range of diseases claimed to benefit from or be caused by the use of the cannabis plant. Cannabis contains more than 600 chemical components. Among these components, cannabinoids are well-known to have multifarious pharmacological activities. In this work, twelve cannabinoids were selected as active compounds through text mining and drug-like properties screening and used for initial protein-target prediction. The disease-associated biological functions and pathways were enriched through GO and KEGG databases. Various biological networks [i.e., protein-protein interaction, …

Flexible Dye-Sensitized Solar Cells Assisted With Lead-Free Perovskite Halide, Judy Fan

Physics Faculty Research

Dye-sensitized solar cells (DSSCs) have shown promising alternative to Si-based counterparts due to low-cost, abundant raw materials, and non-vacuum processing. Here, we report a solution-based process to create flexible DSSCs on aluminum foils. Mesoporous TiO₂ electrode was directly deposited on Al foil through spin casting. After post-thermal annealing, the resultant samples render optical smooth, crack-free, and large nanocrystalline thin films. The as-prepared double-layer porous TiO₂ thin film was incorporated with a porphyrin dye followed by a perovskite halide salt Cs₂SnI₆, as the hole transport material, replacing liquid electrolyte. A transparent conducting plastic sheet was …

Towards Statistical Best Practices For Gender And Sex Data, Suzanne Thornton, D. Roy, S. Parry, D. Lalonde, W. Martinez, R. Ellis, D. Corliss

Mathematics & Statistics Faculty Works

Suzanne Thornton, Dooti Roy, Stephen Parry, Donna LaLonde, Wendy Martinez, Renee Ellis and David Corliss call for a more inclusive – and informative – approach to collecting data on human gender and sex.

Incorporating Microtopography In A Land Surface Model And Quantifying The Effect On The Carbon Cycle, J. D. Graham, D. M. Ricciuto, N. F. Glenn, P. J. Hanson

Geosciences Faculty Publications and Presentations

Northern peatlands are a terrestrial carbon store, with an annual sink of 0.1 Pg C yr⁻¹ and a total storage estimate of 547 Pg C. Northern peatlands are also major contributors of atmospheric methane. Most land surface models do not accurately represent peatland carbon emissions, partly because they do not represent the hydrologic cycle and/or microtopography adequately. Interactions between water table depth and microtopography in peatlands influence decomposition and modulate CO₂ and CH₄ fluxes. A modified version of the land surface component of the Energy Exascale Earth System Model, was recently created to represent the microtopography and …

Late Triassic To Jurassic Magmatic And Tectonic Evolution Of The Intermontane Terranes In Yukon, Northern Canadian Cordillera: Transition From Arc To Syn-Collisional Magmatism And Post-Collisional Lithospheric Delamination, Maurice Colpron, Patrick J. Sack, James L. Crowley, Luke P. Beranek, Murray M. Allan

Geosciences Faculty Publications and Presentations

End-on arc collision and onset of the northern Cordilleran orogen is recorded in Late Triassic to Jurassic plutons in the Intermontane terranes of Yukon, and in development of the synorogenic Whitehorse trough (WT). A synthesis of the extensive data set for these plutons supports interpretation of the magmatic and tectonic evolution of the northern Intermontane terranes. Late Triassic juvenile plutons that locally intrude the Yukon-Tanana terrane represent the northern extension of arc magmatism within Stikinia. Early Jurassic plutons that intrude Stikinia and Yukon-Tanana terranes were emplaced during crustal thickening (200–195 Ma) and subsequent exhumation (190–178 Ma). The syn-collisional magmatism migrated …

Probability Models With Discrete And Continuous Parts, James E. Marengo, David L. Farnsworth

Articles

In mathematical statistics courses, students learn that the quadratic function E ((X – x )-squared) is minimized when x is the mean of the random variable X, and that the graphs of this function for any two distributions of X are simply translates of each other. We focus on the problem of minimizing the function defined by y ( x) = E ( IX – xI-squared ) in the context of mixtures of probability distributions of the discrete, absolutely continuous, and singular continuous types. This problem is important, for example, in Bayesian statistics, when one attempts to compute the decision …

The Role Of Slow Slip Events In The Cascadia Subduction Zone Earthquake Cycle, Juliette P. Saux, Elias G. Molitors Bergman, Eileen L. Evans, John P. Loveless

Geosciences: Faculty Publications

Slow slip events (SSEs) detected on the Cascadia Subduction Zone interface at 30–50 km depth imply a release of accumulated strain. However, studies of interseismic deformation in Cascadia typically find coupling on the upper 30 km of the interface, which is generally accepted as defining the seismogenic zone. Estimates of coupling using net interseismic velocities (including SSE effects) and restricting coupling to the shallow interface may underestimate slip deficit accumulation at depths >30 km. Here, we detect reversals in GPS motion as indications of SSEs, then use SSE displacements to estimate cumulative slow slip from 2007 to 2021. We calculate …

A Bayesian Phase I/Ii Biomarker-Based Design For Identifying Subgroup-Specific Optimal Dose For Immunotherapy, Beibei Guo, Yong Zang

Faculty Publications

Immunotherapy is an innovative treatment that enlists the patient's immune system to battle tumors. The optimal dose for treating patients with an immunotherapeutic agent may differ according to their biomarker status. In this article, we propose a biomarker-based phase I/II dose-finding design for identifying subgroup-specific optimal dose for immunotherapy (BSOI) that jointly models the immune response, toxicity, and efficacy outcomes. We propose parsimonious yet flexible models to borrow information across different types of outcomes and subgroups. We quantify the desirability of the dose using a utility function and adopt a two-stage dose-finding algorithm to find the optimal dose for each …

Belowground Mechanism Reveals Climate Change Impacts On Invasive Clonal Plant Establishment, Surendra Bam, Jacqueline P. Ott, Jack L. Butler, Lan Xu

Natural Resource Management Faculty Publications

Climate change and disturbance can alter invasion success of clonal plants by differentially affecting the clonal traits influencing their establishment as young plants. Clonal traits related to the vegetative reproduction of native Pascopyrum smithii and non-native Bromus inermis grass seedlings were evaluated under altered precipitation frequencies and a single grazing event. Pascopyrum smithii maintained similar vegetative reproduction under three simulated precipitation frequencies whereas B. inermis vegetative reproduction declined as precipitation became more intermittent. Vegetative reproduction of the non-native B. inermis was greater than the native P. smithii under all simulated precipitation frequencies except the most intermittent scenario. A single grazing …

Search Full Text Options Here 3 Of 3 Heat-Mitigated Design And Lorentz Force-Based Steering Of An Mri-Driven Microcatheter Toward Minimally Invasive Surgery, Martin Francis Phelan Iii, Mehmet Efe Tiryaki, Jelena Lazovic, Hunter Gilbert, Metin Sitti

Faculty Publications

Catheters integrated with microcoils for electromagnetic steering under the high, uniform magnetic field within magnetic resonance (MR) scanners (3-7 Tesla) have enabled an alternative approach for active catheter operations. Achieving larger ranges of tip motion for Lorentz force-based steering have previously been dependent on using high power coupled with active cooling, bulkier catheter designs, or introducing additional microcoil sets along the catheter. This work proposes an alternative approach using a heat-mitigated design and actuation strategy for a magnetic resonance imaging (MRI)-driven microcatheter. A quad-configuration microcoil (QCM) design is introduced, allowing miniaturization of existing MRI-driven, Lorentz force-based catheters down to 1-mm …

Tess Giants Transiting Giants. I.: A Noninflated Hot Jupiter Orbiting A Massive Subgiant, N. Saunders, S. K. Grunblatt, D. Huber, K. A. Collins, Eric L.N. Jensen, A. Vanderburg, R. Brahm, A. Jordán, N. Espinoza, T. Henning, M. J. Hobson, S. N. Quinn, G. Zhou, R. P. Butler, L. Crause, R. B. Kuhn, K. M. Mogotsi, C. Hellier, R. Angus, S. Hattori, A. Chontos, G. R. Ricker, J. M. Jenkins, P. Tenenbaum, D. W. Latham, S. Seager, R. K. Vanderspek, J. N. Winn, C. Stockdale, R. Cloutier

Physics & Astronomy Faculty Works

While the population of confirmed exoplanets continues to grow, the sample of confirmed transiting planets around evolved stars is still limited. We present the discovery and confirmation of a hot Jupiter orbiting TOI-2184 (TIC 176956893), a massive evolved subgiant (M_⋆ = 1.53 ± 0.12 M_⊙, R_⋆ = 2.90 ± 0.14 R_⊙) in the Transiting Exoplanet Survey Satellite (TESS) Southern Continuous Viewing Zone. The planet was flagged as a false positive by the TESS Quick-Look Pipeline due to periodic systematics introducing a spurious depth difference between even and odd transits. Using a new pipeline …

On-Demand Generation Of Dark-Bright Soliton Trains In Bose-Einstein Condensates, A. Romero-Ros, Garyfallia C. Katsimiga, P. G. Kevrekidis, B. Prinari, G. Biondini, P. Schmelcher

Physics Faculty Research & Creative Works

The controlled creation of dark-bright (DB) soliton trains in multicomponent Bose-Einstein condensates (BECs) is a topic of ongoing interest. In this work we generalize earlier findings on the creation of dark soliton trains in single-component BECs [A. Romero-Ros, Phys. Rev. A 103, 023329 (2021)2469-992610.1103/PhysRevA.103.023329] to two-component BECs. By choosing suitable filled box-type initial configurations (FBTCs) and solving the direct scattering problem for the defocusing vector nonlinear Schrödinger equation with nonzero boundary conditions we obtain analytical expressions for the DB soliton solutions produced by a general FBTC. It is found that the size of the initial box and the amount of …

Detecting Patches On Road Pavement Images Acquired With 3d Laser Sensors Using Object Detection And Deep Learning, Syed Ibrahim Hassan, Dympna O'Sullivan, Susan Mckeever, Kieran Feighan, David Power, Ray Mcgowan

Articles

Regular pavement inspections are key to good road maintenance and road defect corrections. Advanced pavement inspection systems such as LCMS (Laser Crack Measurement System) can automatically detect the presence of different defects using 3D lasers. However, such systems still require manual involvement to complete the detection of pavement defects. This paper proposes an automatic patch detection system using object detection technique. To our knowledge, this is the first time state-of-the-art object detection models Faster RCNN, and SSD MobileNet-V2 have been used to detect patches inside images acquired by LCMS. Results show that the object detection model can successfully detect patches …

Corrected Tilt Calculation For Atmospheric Pressure-Induced Seismic Noise, Richard Raspet, Craig J. Hickey, Bipin Koirala

Faculty and Student Publications

In a literature search on the coupling of wind-generated pressure fluctuations into seismic noise, it was noticed that the expression for the angular tilt induced by pressure fluctuations in the seminal paper “A preliminary investigation into the relationship between long-period seismic noise and local fluctuations in the atmospheric pressure” by G. G. Sorrells was only valid at the surface. A search of the literature which cites the Sorrells paper was performed to see if any subsequent research corrected this error, and what effect the error might have on the research. A recent paper by Tanimoto and Wang notes the correct …

Effect Of As Flux On Inas Submonolayer Quantum Dot Formation For Infrared Photodetectors, K. D. Vallejo, P. J. Simmonds

Physics Faculty Publications and Presentations

The performance of infrared photodetectors based on submonolayer quantum dots was investigated as a function of the arsenic flux. All the devices showed similar figures of merit and a very high specific detectivity above 1 × 10¹¹ cm Hz^1/2/W at 12 K, despite the fact that cross-sectional scanning tunneling microscopy images pointed out a strong reduction in the density of such nanostructures with decreasing arsenic flux. This contrast is a consequence of the small size and low In content of the submonolayer quantum dots that lead to a strong delocalization of the electrons wave function and, therefore, …

Propagation Of Inflowing Urban Stormwater Pulses Through Reservoir Embayments, Megan Fork, Ryan A. Mcmanamay, James B. Heffernan

Biology Faculty Publications

Flashy hydrology and high solute loads in stormflow are well-studied effects of the built environment on urban streams. The physical and chemical interactions between inflowing stormwater of urban streams and their termination in large impoundments, however, is poorly understood. Determining the spatial distribution of urban stormwater in reservoirs is an important step in understanding the effects of the heat and contaminant loads in these systems, which provide multiple services for adjacent cities. Here, we show that signals of stormwater from a small urban stream can propagate more than 800 m from the stream mouth. Stormflow can also break down the …

Ppld Is A De-N-Acetylase Of The Cell Wall Linkage Unit Of Streptococcal Rhamnopolysaccharides, Jeffrey S. Rush, Prakash Parajuli, Alessandro Ruda, Jian Li, Amol Arunrao Pohane, Svetlana Zamakhaeva, Mohammad M. Rahman, Jennifer C. Chang, Artemis Gogos, Cameron W. Kenner, Gérard Lambeau, Michael J. Federle, Konstantin V. Korotkov, Göran Widmalm, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

The cell wall of the human bacterial pathogen Group A Streptococcus (GAS) consists of peptidoglycan decorated with the Lancefield group A carbohydrate (GAC). GAC is a promising target for the development of GAS vaccines. In this study, employing chemical, compositional, and NMR methods, we show that GAC is attached to peptidoglycan via glucosamine 1-phosphate. This structural feature makes the GAC-peptidoglycan linkage highly sensitive to cleavage by nitrous acid and resistant to mild acid conditions. Using this characteristic of the GAS cell wall, we identify PplD as a protein required for deacetylation of linkage N-acetylglucosamine (GlcNAc). X-ray structural analysis indicates …

Iowa Waste Reduction Center Newsletter, February 2022, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

Inside this Issue:

--- Upcoming Events
--- IWRC Energy Trends Workshop
--- Iowa EASY Air "How-To" Webinars
--- UNI Hosts Cedar Valley Sustainability Business Workshops and Competition
--- Updates from UNI's Counseling CenterMinor Source Emissions Inventory Assistance
--- Industry News

Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Fungi that bind leaf litter into mats and produce white-rot via degradation of lignin and other aromatic compounds influence forest nutrient cycling and soil fertility. Extent of white-rot litter mats formed by basidiomycete fungi in Puerto Rico decreased in response to disturbances—a simulated hurricane treatment executed by canopy trimming and debris addition in 2014, a drought in 2015, a treefall, and two hurricanes 10 days apart in September 2017. Percent fungal litter mat cover ranged from 0.4% after Hurricanes Irma and Maria to a high of 53% in forest with undisturbed canopy prior to the 2017 hurricanes, with means mostly …

2022 Gray Wolf Questions And Answers, United States Fish And Wildlife Service

United States Fish and Wildlife Service: Publications

2022 Gray Wolf Questions and Answers

What does the February 10, 2022, ruling mean?

How does this ruling affect wolves in the Northern Rocky Mountains?

When does the court decision to vacate the delisting rule go into effect?

What is the legal status of gray wolves as of this ruling?

Is the Service continuing its status review of wolves in the western United States?

Is emergency listing an option for the Northern Rocky Mountain population?

Are wolf hunts going to stop as a result of the court decision?

How does this ruling affect wolves in Yellowstone National Park?

Where can …

Learning Fruit Class From Short Wave Near Infrared Spectral Features, An Ai Approach Towards Determining Fruit Type, Ayesha Zeb, Waqar Shahid Qureshi, Abdul Ghafoor, Dympna O'Sullivan

Conference papers

This paper analyzes the potential of using shortwave NIRS (near-infrared spectroscopy) for fruit classification problems. The research focuses on O-H and C-H overtone features of fruit and its correlation with NIRS and therefore opens a new dimension of fruit classification problems using NIRS. Eleven fruits, which include apple, cherry, hass, kiwi, grapes, mango, melon, orange, loquat, plum, and apricot, were used in this study to cover physical characteristics such as peel thinness, pulp, seed thickness, and size. NIR spectral data is collected using the industry-standard F-750 fruit quality meter (wavelength range 300-1100nm) for all fruit mentioned above. Different shallow machine …

Special Issue: Microbiota-Gut-Brain Axis, Mark Obrenovich, Prakash Reddy

Chemistry Faculty Research & Creative Works

No abstract provided.

Collisional Excitation And Non-Lte Modeling Of Interstellar Chiral Propylene Oxide, Karlis Dzenis, Alexandre Faure, B. A. Mcguire, A. J. Remijan, P. J. Dagdigian, C. Rist, Richard Dawes, Ernesto Quintas-Sánchez, F. Lique, M. Hochlaf

Chemistry Faculty Research & Creative Works

The first set of theoretical rotational cross sections for propylene oxide (CH₃CHCH₂O) colliding with cold He atoms has been obtained at the full quantum level using a high-accuracy potential energy surface. By scaling the collision reduced mass, rotational rate coefficients for collisions with para-H₂ are deduced in the temperature range 5-30 K. These collisional coefficients are combined with radiative data in a non-LTE radiative transfer model in order to reproduce observations of propylene oxide made toward the Sagittarius B2(N) molecular cloud with the Green Bank and Parkes radio telescopes. The three detected absorption lines are …