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Articles 1 - 15 of 15
Full-Text Articles in Entire DC Network
The Influence Of Subhaloes On Host Halo Properties, Lorena Mezini, Catherine E. Fielder, Andrew R. Zentner, Yao-Yuan Mao, Kuan Wang, Hao-Yi Wu
The Influence Of Subhaloes On Host Halo Properties, Lorena Mezini, Catherine E. Fielder, Andrew R. Zentner, Yao-Yuan Mao, Kuan Wang, Hao-Yi Wu
Physics Faculty Publications and Presentations
Within the ΛCDM cosmology, dark matter haloes are composed of both a smooth component and a population of smaller gravitationally bound subhaloes. These components are often treated as a single halo when properties, such as density profiles, are extracted from simulations. Recent work has shown that density profiles change substantially when subhalo mass is excluded. In this paper, we expand on this result by analysing three specific host halo properties – concentration (cNFW), spin (λB), and shape (c/a) – when calculated only from the smooth component of the halo. This analysis …
Interaction Of ΒL- And Γ-Crystallin With Phospholipid Membrane Using Atomic Force Microscopy, Nawal K. Khadka, Preston Hazen, Dieter Haemmerle, Laxman Mainali
Interaction Of ΒL- And Γ-Crystallin With Phospholipid Membrane Using Atomic Force Microscopy, Nawal K. Khadka, Preston Hazen, Dieter Haemmerle, Laxman Mainali
Physics Faculty Publications and Presentations
Highly concentrated lens proteins, mostly β- and γ-crystallin, are responsible for maintaining the structure and refractivity of the eye lens. However, with aging and cataract formation, β- and γ-crystallin are associated with the lens membrane or other lens proteins forming high-molecular-weight proteins, which further associate with the lens membrane, leading to light scattering and cataract development. The mechanism by which β- and γ-crystallin are associated with the lens membrane is unknown. This work aims to study the interaction of β- and γ-crystallin with the phospholipid membrane with and without cholesterol (Chol) with the overall goal of understanding the role of …
Luminous Radio Emission From The Superluminous Supernova 2017ens At 3.3 Yr After Explosion, Raffaella Margutti, J. S. Bright, D. J. Matthews, D. L. Coppejans, K. D. Alexander, E. Berger, M. Bietenholz, R. Chornock, L. Demarchi, M. R. Drout, T. Eftekhari, W. V. Jacobson-Galán, T. Laskar, D. Milisavljevic, K. Murase, M. Nicholl, C. M. B. Omand, M. Stroh, G. Terreran, B. A. Vanderley
Luminous Radio Emission From The Superluminous Supernova 2017ens At 3.3 Yr After Explosion, Raffaella Margutti, J. S. Bright, D. J. Matthews, D. L. Coppejans, K. D. Alexander, E. Berger, M. Bietenholz, R. Chornock, L. Demarchi, M. R. Drout, T. Eftekhari, W. V. Jacobson-Galán, T. Laskar, D. Milisavljevic, K. Murase, M. Nicholl, C. M. B. Omand, M. Stroh, G. Terreran, B. A. Vanderley
Physics Faculty Publications and Presentations
We present the results from a multiyear radio campaign of the superluminous supernova (SLSN) SN 2017ens, which yielded the earliest radio detection of an SLSN to date at the age of ∼3.3 yr after explosion. SN 2017ens was not detected at radio frequencies in the first ∼300 days but reached Lν ≈ 1028 erg s−1 cm−2 Hz−1 at ν ∼ 6 GHz, ∼1250 days post explosion. Interpreting the radio observations in the context of synchrotron radiation from the supernova shock interaction with the circumstellar medium (CSM), we infer an effective mass-loss rate Ṁ ≈ 10 …
Binding Of ΒL-Crystallin With Models Of Animal And Human Eye Lens-Lipid Membrane, Preston Hazen, Geraline Trossi-Torres, Nawal K. Khadka, Raju Timsina, Laxman Mainali
Binding Of ΒL-Crystallin With Models Of Animal And Human Eye Lens-Lipid Membrane, Preston Hazen, Geraline Trossi-Torres, Nawal K. Khadka, Raju Timsina, Laxman Mainali
Physics Faculty Publications and Presentations
Several discoveries show that with age and cataract formation, β-crystallin binds with the lens membrane or associates with other lens proteins, which bind with the fiber cell plasma membrane, accompanied by light scattering and cataract formation. However, how lipids (phospholipids and sphingolipids) and cholesterol (Chol) influence β-crystallin binding to the membrane is unclear. This research aims to elucidate the role of lipids and Chol in the binding of β-crystallin to the membrane and the membrane’s physical properties (mobility, order, and hydrophobicity) with β-crystallin binding. We used electron paramagnetic resonance (EPR) spin-labeling methods to investigate the binding of βL-crystallin …
Modulation Of Voltage-Gating And Hysteresis Of Lysenin Channels By Cu2+ Ions, Andrew Bogard, Pangaea W. Finn, Aviana R. Smith, Ilinca M. Flacau, Rose Whiting, Daniel Fologea
Modulation Of Voltage-Gating And Hysteresis Of Lysenin Channels By Cu2+ Ions, Andrew Bogard, Pangaea W. Finn, Aviana R. Smith, Ilinca M. Flacau, Rose Whiting, Daniel Fologea
Physics Faculty Publications and Presentations
The intricate voltage regulation presented by lysenin channels reconstituted in artificial lipid membranes leads to a strong hysteresis in conductance, bistability, and memory. Prior investigations on lysenin channels indicate that the hysteresis is modulated by multivalent cations which are also capable of eliciting single-step conformational changes and transitions to stable closed or sub-conducting states. However, the influence on voltage regulation of Cu2+ ions, capable of completely closing the lysenin channels in a two-step process, was not sufficiently addressed. In this respect, we employed electrophysiology approaches to investigate the response of lysenin channels to variable voltage stimuli in the presence …
Self-Calibrating Optical Galaxy Cluster Selection Bias Using Cluster, Galaxy, And Shear Cross-Correlations, Chenxiao Zeng, Andrés N. Salcedo, Hao-Yi Wu, Christopher M. Hirata
Self-Calibrating Optical Galaxy Cluster Selection Bias Using Cluster, Galaxy, And Shear Cross-Correlations, Chenxiao Zeng, Andrés N. Salcedo, Hao-Yi Wu, Christopher M. Hirata
Physics Faculty Publications and Presentations
The clustering signals of galaxy clusters are powerful tools for self-calibrating the mass–observable relation and are complementary to cluster abundance and lensing. In this work, we explore the possibility of combining three correlation functions – cluster lensing, the cluster–galaxy cross-correlation function, and the galaxy autocorrelation function – to self-calibrate optical cluster selection bias, the boosted clustering and lensing signals in a richness-selected sample mainly caused by projection effects. We develop mock catalogues of redMaGiC-like galaxies and redMaPPer-like clusters by applying halo occupation distribution models to N-body simulations and using counts-in-cylinders around massive haloes as a richness proxy. In addition …
Modelling Galaxy Cluster Triaxiality In Stacked Cluster Weak Lensing Analyses, Hao-Yi Wu
Modelling Galaxy Cluster Triaxiality In Stacked Cluster Weak Lensing Analyses, Hao-Yi Wu
Physics Faculty Publications and Presentations
Counts of galaxy clusters offer a high-precision probe of cosmology, but control of systematic errors will determine the accuracy of this measurement. Using Buzzard simulations, we quantify one such systematic, the triaxiality distribution of clusters identified with the redMaPPer optical cluster finding algorithm, which was used in the Dark Energy Survey Year-1 (DES Y1) cluster cosmology analysis. We test whether redMaPPer selection biases the clusters’ shape and orientation and find that it only biases orientation, preferentially selecting clusters with their major axes oriented along the line of sight. Modelling the richness–mass relation as log-linear, we find that the log-richness amplitude …
Hypo-Osmotic Stress And Pore-Forming Toxins Adjust The Lipid Order In Sheep Red Blood Cell Membranes, Rose Whiting, Sevio Stanton, Maryna Kucheriava, Aviana R. Smith, Matt Pitts, Daniel Robertson, Jacob Kammer, Zhiyu Li, Daniel Fologea
Hypo-Osmotic Stress And Pore-Forming Toxins Adjust The Lipid Order In Sheep Red Blood Cell Membranes, Rose Whiting, Sevio Stanton, Maryna Kucheriava, Aviana R. Smith, Matt Pitts, Daniel Robertson, Jacob Kammer, Zhiyu Li, Daniel Fologea
Physics Faculty Publications and Presentations
Lipid ordering in cell membranes has been increasingly recognized as an important factor in establishing and regulating a large variety of biological functions. Multiple investigations into lipid organization focused on assessing ordering from temperature-induced phase transitions, which are often well outside the physiological range. However, particular stresses elicited by environmental factors, such as hypo-osmotic stress or protein insertion into membranes, with respect to changes in lipid status and ordering at constant temperature are insufficiently described. To fill these gaps in our knowledge, we exploited the well-established ability of environmentally sensitive membrane probes to detect intramembrane changes at the molecular level. …
Stability Of Retinol In Liposomes As Measured By Fluorescence Lifetime Spectroscopy And Flim, Louis Sumrall, L. Smith, Elmukhtar Ehmed Alhatmi, Yekaterina G. Chmykh, D. Mitchell, Jay Nadeau
Stability Of Retinol In Liposomes As Measured By Fluorescence Lifetime Spectroscopy And Flim, Louis Sumrall, L. Smith, Elmukhtar Ehmed Alhatmi, Yekaterina G. Chmykh, D. Mitchell, Jay Nadeau
Physics Faculty Publications and Presentations
Retinol shows complex photophysical properties that make it potentially useful as an exogenous or endogenous probe of membrane microenvironment, but it has not been fully explored. In this study, we use bulk fluorescence lifetime measurements and fluorescence lifetime imaging microscopy (FLIM) to examine the stability of retinol in phosphatidylcholine (PC) multilamellar and unilamellar vesicles with and without cholesterol. We find that both light and exposure to ambient temperature and oxygen contribute to retinol degradation, with the addition of an antioxidant such as butylated hydroxytoluene (BHT) essential to provide stability, especially in the absence of cholesterol. With exposure to ultraviolet light …
Microbial Motility At The Bottom Of North America: Digital Holographic Microscopy And Genomic Motility Signatures In Badwater Spring, Death Valley National Park, Carl Snyder, Jakob P. Centlvre, Shrikant Bhute, Jay Nadeau, Multiple Additional Authors
Microbial Motility At The Bottom Of North America: Digital Holographic Microscopy And Genomic Motility Signatures In Badwater Spring, Death Valley National Park, Carl Snyder, Jakob P. Centlvre, Shrikant Bhute, Jay Nadeau, Multiple Additional Authors
Physics Faculty Publications and Presentations
Motility is widely distributed across the tree of life and can be recognized by microscopy regardless of phylogenetic affiliation, biochemical composition, or mechanism. Microscopy has thus been proposed as a potential tool for detection of biosignatures for extraterrestrial life; however, traditional light microscopy is poorly suited for this purpose, as it requires sample preparation, involves fragile moving parts, and has a limited volume of view. In this study, we deployed a field-portable digital holographic microscope (DHM) to explore microbial motility in Badwater Spring, a saline spring in Death Valley National Park, and complemented DHM imaging with 16S rRNA gene amplicon …
A Simple In Situ Method For Optimizing Settings For The Einzel Lens Elements In A Focused Ion Beam, Rich Swinford, Erik Sanchez
A Simple In Situ Method For Optimizing Settings For The Einzel Lens Elements In A Focused Ion Beam, Rich Swinford, Erik Sanchez
Physics Faculty Publications and Presentations
Ion beams have had an incredible impact on research in the past couple of decades. One major reason for this is the continued development of systems having optimal beam currents that allows one to image more clearly at different spot sizes to include higher currents that allow for faster milling. The advancements for Focused ion beam (FIB) columns have developed rapidly due to the computational optimization of lens designs. However, once a system has been produced, the optimal column settings for these lenses may change or simply become obscure. Our work involves regaining this optimization with the newly applied values …
Thin Film Deposition Of Mop, A Topological Semimetal, Robert Browning, Paul Plachinda, Raj Solanki
Thin Film Deposition Of Mop, A Topological Semimetal, Robert Browning, Paul Plachinda, Raj Solanki
Physics Faculty Publications and Presentations
MoP is a topological semimetal which has drawn attention due to its unique electrical and optical properties resulting from massless electrons. In order to utilize these properties for practical applications, it is necessary to develop a technique to produce high-quality, large-scale thin films of this 2D material. We report below our initial results of growth of MoP thin films using atomic layer deposition (ALD), where the film grows layer-by-layer. These films were grown on 5 cm × 5 cm silicon oxide coated Si wafers. Resistivity versus temperature measurements show that these films are metallic and includes a partial superconducting phase. …
Quantification Of Age-Related Changes In The Lateral Organization Of The Lipid Portion Of The Intact Membranes Isolated From The Left And Right Eye Lenses Of The Same Human Donor, Laxman Mainali, Marija Raguz, Witold Karol Subczynski
Quantification Of Age-Related Changes In The Lateral Organization Of The Lipid Portion Of The Intact Membranes Isolated From The Left And Right Eye Lenses Of The Same Human Donor, Laxman Mainali, Marija Raguz, Witold Karol Subczynski
Physics Faculty Publications and Presentations
The continuous wave EPR spin-labeling method was used to evaluate age-related changes in the amounts of phospholipids (PLs) and cholesterol (Chol) in domains present in intact, cortical, and nuclear fiber cell plasma membranes isolated separately from the left and right eye lenses of the same human donor. The relative amounts of boundary plus trapped PLs were evaluated with the PL analog 12-doxylstearic acid spin label (12-SASL) and the relative amounts of trapped Chol with the Chol analog androstane spin label (ASL). The donors ranged in age from 15 to 70 years. Both the left and right eye lenses from donors …
Recent Advances In Experimental Design And Data Analysis To Characterize Prokaryotic Motility, Megan M. Dubay, Jacqueline Acres, Max Riekeles, Jay Nadeau
Recent Advances In Experimental Design And Data Analysis To Characterize Prokaryotic Motility, Megan M. Dubay, Jacqueline Acres, Max Riekeles, Jay Nadeau
Physics Faculty Publications and Presentations
Bacterial motility plays a key role in important cell processes such as chemotaxis and biofilm formation, but is challenging to quantify due to the small size of the individual microorganisms and the complex interplay of biological and physical factors that influence motility phenotypes. Swimming, the first type of motility described in bacteria, still remains largely unquantified. Light microscopy has enabled qualitative characterization of swimming patterns seen in different strains, such as run and tumble, run-reverse-flick, run and slow, stop and coil, and push and pull, which has allowed for elucidation of the underlying physics. However, quantifying these behaviors (e.g., identifying …
Electromagnetic Radiation From A Spherical Static Current Source Coupled To Harmonic Axion Field, Railing Chang, Huai-Yi Xie, P. T. Leung
Electromagnetic Radiation From A Spherical Static Current Source Coupled To Harmonic Axion Field, Railing Chang, Huai-Yi Xie, P. T. Leung
Physics Faculty Publications and Presentations
The electromagnetic fields generated from a static current source on a spherical surface are calculated in the framework of axion electrodynamics to first order in the coupling parameter. Comparisons of the results are made with reference to various results obtained in conventional Maxwell electrodynamics, as well as previous results obtained for point magnetic dipole source coupled to harmonic axion fields. Distinct features from the results so obtained are highlighted for possible experimental probing of the axions via electromagnetic interactions. In particular, electromagnetic radiation from sources with strong magnetic field is studied which may enable the detection of a cosmic …