News and Events

Gunnar Schroeder
Friday, March 28, 12:00 PM (C215 ESC)
Structure Determination of Amyloid Fibrils by Cryo-EM

A variety of mouse models are used in Alzheimer's disease (AD) research. However, little is known about the structural differences in aggregated Aβ between mouse models and humans or in vitro structures. These differences might help to understand why fibril-targeting drug candidates show efficacy when tested in mouse models but often fail to show the desired effect in clinical trials. We determined the structures of nine ex vivo Aβ fibrils from six different mouse models by cryogenic-electron microscopy (cryo-EM). We found that these fibril structures are different from the most dominant structures found in AD patients. A detailed assessment of the Aβ fibril structure is therefore important to the selection of appropriate mouse models for the preclinical development of novel plaque-targeting therapeutics in AD. In addition to protein deposits, such as plaques in AD and Lewy bodies in α-synucleinopathies like Parkinson’s disease (PD), a high concentration of lipids is also found, suggesting a potential role for lipids in disease progression. We present cryo-EM studies of Aβ40 and α-synuclein fibrils formed in the presence of liposomes. These structures provide detailed insights into fibril-lipid interactions and show that the fibrils can take up substantial amounts of lipids during formation, which results in lipid-decorated fibrils. This supports the notion that lipid extraction from cell membranes may be a mechanism contributing to fibril toxicity. Understanding these fibril-lipid interactions offers structural insights into disease-relevant processes in AD and PD.

Thumbnail of A Blue Banded Blood Moon
What causes a blue band to cross the Moon during a lunar eclipse? The blue band is real but usually quite hard to see. The featured HDR image of last week's lunar eclipse, however -- taken from Norman, Oklahoma (USA) -- has been digitally processed to exaggerate the colors. The gray color on the upper right of the top lunar image is the Moon's natural color, directly illuminated by sunlight. The lower parts of the Moon on all three images are not directly lit by the Sun since it is being eclipsed -- it is in the Earth's shadow. It is faintly lit, though, by sunlight that has passed deep through Earth's atmosphere. This part of the Moon is red -- and called a blood Moon -- for the same reason that Earth's sunsets are red: because air scatters away more blue light than red. The unusual purple-blue band visible on the upper right of the top and middle images is different -- its color is augmented by sunlight that has passed high through Earth's atmosphere, where red light is better absorbed by ozone than blue. Celestial Surprise: What picture did APOD feature on your birthday? (post 1995)
Mount Timpanogos with sky above
Temperature: F
Rel. Humidity: %
Pressure: Inches Hg
Image for Dr. John Colton’s Sabbatical to the National Renewable Energy Laboratory
Dr. John Colton embarked on a six-month sabbatical at the National Renewable Energy Laboratory (NREL) in Colorado to explore the use of terahertz radiation in probing the chiral properties of hybrid perovskite materials, a research area previously unfamiliar to him.
Image for Nathan Powers, Updated labs and AAPT lab committee work
Dr. Powers initiated the effort to update BYU’s physics undergraduate lab curriculum in 2015. The revamped curriculum, aimed at teaching students how to construct knowledge from experiments.
Image for BYU Women Represent at CUWiP 2024
21 women student attend conference at Montana State University, where students engaged in keynote speeches, panels, and research presentations.

Selected Publications

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By Spencer Gardiner, Christopher Haynie, and Dennis Della Corte
Abstract:

The Allotrope Foundation (AF) started as a group of pharmaceutical companies, instrument, and software vendors that set out to simplify the exchange of data in the laboratory. After a decade of work, they released products that have found adoption in various companies. Most recently, the Allotrope Simple Model (ASM) was developed to speed up and widen the adoption. As a result, the Foundation has recently added chemical companies and, importantly, is reworking its business model to lower the entry barrier for smaller companies. Here, we present the proceedings from the Allotrope Connect Fall 2023 conference and summarize the technical and organizational developments at the Foundation since 2020.

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Abstract:

Q-balls are non-topological solitons arising in scalar field theories. Solutions for rotating Q-balls (and the related boson stars) have been shown to exist when the angular momentum is equal to an integer multiple of the Q-ball charge Q. Here we consider the possibility of classically long-lived metastable rotating Q-balls with small angular momentum, even for large charge, for all scalar theories that support non-rotating Q-balls. This is relevant for rotating extensions of Q-balls and related solitons such as boson stars as it impacts their cosmological phenomenology.

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By Levi T. Moats and Kent L. Gee (et al.)
Abstract:

Migratory bird refuge soundscapes are seasonally dynamic due to changes in wildlife populations. Some of the most prominent acoustical events in a bird refuge are the morning and evening avian choruses, particularly during spring and early summer when breeding activity of birds is high. This event is acoustically dynamic, reacting to both biotic and abiotic drivers. One such driver is the presence of standing water. For this study, near-continuous spectral data were collected at the U.S. Federal Fish and Wildlife Services Bear River Migratory Bird Refuge. Although data fidelity can be compromised by wind and rain, changes in the avian chorus characteristics over time are observed. These changes over time are observed to correlate with times management at the refuge drained the wetland area surrounding the recording sites. Recording sites that were close to drained wetland units saw decreases in the average sound pressure level during the dawn chorus, sometimes on the order of 20 dB.

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By Logan T. Mathews and Kent L. Gee
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Understanding the acoustic source characteristics of supersonic jets is vital to accurate noise field modeling and jet noise reduction strategies. This paper uses advanced, coherence-based partial field decomposition methods to characterize the acoustic sources in an installed, supersonic GE F404 engine. Partial field decomposition is accomplished using an equivalent source reconstruction via acoustical holography. Bandwidth is extended through the application of an array phase-unwrapping and interpolation scheme. The optimized-location virtual reference method is used. Apparent source distributions and source-related partial fields are shown as a function of frequency. Local maxima are observed in holography reconstructions at the nozzle lipline, distinct in frequency and space. The lowest-frequency local maximum may relate to noise generated by large-scale turbulence structures in the convectively subsonic region of the flow. Other local maxima are correlated primarily with Mach wave radiation originating from throughout the shear layer and into the fully mixed region downstream of the potential core tip. Source-elucidating decompositions show that the order and behavior of the decomposition lend to the local maxima being related to distinct subsources. Between the local maxima, however, there may be a combination of sources active, which is likely the cause of the spatiospectral lobes observed in other full-scale, supersonic jets.

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We perform a general analysis of thin-wall Q-balls in anti-de Sitter (AdS) space. We provide numeric solutions and highly accurate analytic approximations over much of the parameter space. These analytic solutions show that AdS Q-balls exhibit significant differences from the corresponding flat-space solitons. This includes having a maximum radius beyond which the Q-balls are unstable to a new type of state where the Q-ball coexists with a gas of massive particles. The phase transition to this novel state is found to be a zero-temperature third-order transition. This, through the AdS/CFT correspondence, has implications for a scalar condensate in the boundary theory.

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By Adam Bennion (et al.)
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Preservice elementary teachers enter their science methods courses with a range of prior experience with science practice. Those prior experiences likely inform much of their science pedagogy and goals. In this study, the authors examine how a cohort of preservice elementary teachers engaged in science practice as they learned content in a physics course. Drawing on course documents, videorecords, and artifacts from in-class lab work and interviews with nine participants, the authors used an asset-based, mixed methods approach. The authors developed rubrics to assess the level of sophistication the participants used while engaging in science practice on a scale of 1 (pre-novice) to 4 (experienced). They used descriptive statistics and ANOVA's to interpret the performance of the participants in addition to grounded theory open coding of interviews to determine the participants' level of prior experience with science practice. The findings suggest that these preservice teachers primarily engaged in science practices at a novice level. In general, their sophistication scores on the rubric aligned with their prior experience. The findings suggest that while one content course steeped in science practice was not enough to significantly change preservice teachers' engagement, it can provide a needed starting place and that it likely takes time to develop these skills. The findings have implications for both teacher educators and researchers who hope to increase the use of science practice as a method of learning science content.