Papers by Brandon Johnson
Cells, 2021
Multiple myeloma (MM) is a currently incurable hematologic cancer. Patients that initially respon... more Multiple myeloma (MM) is a currently incurable hematologic cancer. Patients that initially respond to therapeutic intervention eventually relapse with drug resistant disease. Thus, novel treatment strategies are critically needed to improve patient outcomes. Our group has developed a novel cyclic peptide referred to as MTI-101 for the treatment of MM. We previously reported that acquired resistance to HYD-1, the linear form of MTI-101, correlated with the repression of genes involved in store operated Ca2+ entry (SOCE): PLCβ, SERCA, ITPR3, and TRPC1 expression. In this study, we sought to determine the role of TRPC1 heteromers in mediating MTI-101 induced cationic flux. Our data indicate that, consistent with the activation of TRPC heteromers, MTI-101 treatment induced Ca2+ and Na+ influx. However, replacing extracellular Na+ with NMDG did not reduce MTI-101-induced cell death. In contrast, decreasing extracellular Ca2+ reduced both MTI-101-induced Ca2+ influx as well as cell death....
American Journal of Medical Genetics Part A, 2020
General rights Copyright and moral rights for the publications made accessible in the public port... more General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
American Journal of Kidney Diseases, 2018
intellectual content during manuscript drafting or revision and accepts accountability for the ov... more intellectual content during manuscript drafting or revision and accepts accountability for the overall work by ensuring that questions pertaining to the accuracy or integrity of any portion of the work are appropriately investigated and resolved.
Journal of Geophysical Research: Planets, 2017
Motivated by recent evidence for subduction in Europa's ice shell, we explore the geophysical fea... more Motivated by recent evidence for subduction in Europa's ice shell, we explore the geophysical feasibility of this process. Here we construct a simple model to track the evolution of porosity and temperature within a slab that is forced to subduct. We also vary the initial salt content in Europa's ice shell and determine the buoyancy of our simulated subducting slab. We find that porosity and salt content play a dominant role in determining whether the slab is nonbuoyant and subduction in Europa's ice shell is actually possible. Generally, we find that initially low porosities and high salt contents within the conductive lid are more conducive to subduction. If salt contents are laterally homogenous, and Europa has a reasonable surface porosity of ϕ 0 = 0.1, the conductive portion of Europa's shell must have salt contents exceeding~22% for subduction to occur. However, if salt contents are laterally heterogeneous, with salt contents varying by a few percent, subduction may occur for a surface porosity of ϕ 0 = 0.1 and overall salt contents of~5%. Thus, we argue that under plausible conditions, subduction in Europa's ice shell is possible. Moreover, assuming that subduction is actively occurring or has occurred in Europa's recent past provides important constraints on the structure and composition of the ice shell. Plain Language Summary Europa, one of Jupiter's icy moons, has features that look similar to mid-ocean spreading ridges, and recent observations suggest that Europa may also have something similar to subduction zones. This implies that Europa may be the only planetary body other than Earth to have plate tectonics. We construct a computer simulation to track the temperature and compaction of ice as it sinks into warmer underlying ice. When ice warms up, it becomes less dense and easier to compact. The salt content of Europa's plates is also important because salt is denser than ice. The temperature, salt content, and how compacted the ice is determine the density and whether the ice can sink. We find that if the salt content of Europa's ice shell varies by few percent from place to place, then the plates can sink. This supports the idea that something like plate tectonics is occurring on Europa and may tell us about the composition of Europa's ice shell. Our work also implies that the plates will sink all the way to Europa's subsurface ocean. This is important because material from the surface of Europa could act as food for life that may exist in Europa's ocean.
This report is one in a series of Electrification Futures Study (EFS) publications. The EFS is a ... more This report is one in a series of Electrification Futures Study (EFS) publications. The EFS is a multi-year research project to explore widespread electrification in the future energy system of the United States. This report documents a new model, the demand-side grid (dsgrid) model, which was developed for the EFS and in recognition of a general need for a more detailed understanding of electricity load. dsgrid utilizes a suite of bottom-up engineering models across all major economic sectors-transportation, residential and commercial buildings, and industry-to develop hourly electricity consumption profiles for every county in the contiguous United States (CONUS). The consumption profiles are available by subsector and end use as well as in aggregate. This report documents a bottom-up modeling assessment of historical (2012) consumption and explains the key inputs, methodology, assumptions, and limitations of dsgrid. The EFS is specifically designed to examine electric technology cost advancement and adoption for end uses across all major economic sectors as well as electricity consumption growth and load profiles, future power system infrastructure development and operations, and the economic and environmental implications of electrification. Because of the expansive scope and the multiyear duration of the study, research findings and supporting data will be published as a series of reports, with each report released on its own timeframe. Future research to be presented in future planned EFS publications will rely on dsgrid to analyze the hourly electricity consumption under scenarios with various levels of electrification. In addition to providing electricity consumption data for the planned EFS analysis, dsgrid can be used for other analysis outside the EFS research umbrella. More information and the supporting data associated with this report, links to other reports in the EFS study, and information about the broader study are available at www.nrel.gov/efs.
Geophysical Research Letters, 2017
We explore the striking difference between the mobility of long runout landslides on the Earth an... more We explore the striking difference between the mobility of long runout landslides on the Earth and Mars. We simulate long runout landslides as granular flow using a soft-particle code. Differences in drop height explain the difference in volume mobility trends of martian and terrestrial landslides.
Icarus, 2018
The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having... more The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having experienced only modest modification by subsequent impacts and volcanism. Orientale is often treated as the type example of a multiring basin, with three prominent rings outside of the inner depression: the Inner Rook Montes, the Outer Rook Montes, and the Cordillera. Here we use gravity data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to reveal the subsurface structure of Orientale and its ring system. Gradients of the gravity data reveal a continuous ring dike intruded into the Outer Rook along the plane of the fault associated with the ring scarp. The volume of this ring dike is ~18 times greater than the volume of all extrusive mare deposits associated with the basin. The gravity gradient signature of the Cordillera ring indicates an offset along the fault across a shallow density interface, interpreted to be the base of the low-density ejecta blanket. B...
Science advances, 2016
The presence, formation, and migration of giant planets fundamentally shape planetary systems. Ho... more The presence, formation, and migration of giant planets fundamentally shape planetary systems. However, the timing of the formation and migration of giant planets in our solar system remains largely unconstrained. Simulating planetary accretion, we find that giant planet migration produces a relatively short-lived spike in impact velocities lasting ~0.5 My. These high-impact velocities are required to vaporize a significant fraction of Fe,Ni metal and silicates and produce the CB (Bencubbin-like) metal-rich carbonaceous chondrites, a unique class of meteorites that were created in an impact vapor-melt plume ~5 My after the first solar system solids. This indicates that the region where the CB chondrites formed was dynamically excited at this early time by the direct interference of the giant planets. Furthermore, this suggests that the formation of the giant planet cores was protracted and the solar nebula persisted until ~5 My.
Science (New York, N.Y.), Oct 28, 2016
Multiring basins, large impact craters characterized by multiple concentric topographic rings, do... more Multiring basins, large impact craters characterized by multiple concentric topographic rings, dominate the stratigraphy, tectonics, and crustal structure of the Moon. Using a hydrocode, we simulated the formation of the Orientale multiring basin, producing a subsurface structure consistent with high-resolution gravity data from the Gravity Recovery and Interior Laboratory (GRAIL) spacecraft. The simulated impact produced a transient crater, ~390 kilometers in diameter, that was not maintained because of subsequent gravitational collapse. Our simulations indicate that the flow of warm weak material at depth was crucial to the formation of the basin's outer rings, which are large normal faults that formed at different times during the collapse stage. The key parameters controlling ring location and spacing are impactor diameter and lunar thermal gradients.
Science (New York, N.Y.), Jan 28, 2016
The Orientale basin is the youngest and best-preserved major impact structure on the Moon. We use... more The Orientale basin is the youngest and best-preserved major impact structure on the Moon. We used the Gravity Recovery and Interior Laboratory (GRAIL) spacecraft to investigate the gravitational field of Orientale at 3- to 5-kilometer (km) horizontal resolution. A volume of at least (3.4 ± 0.2) × 10(6) km(3) of crustal material was removed and redistributed during basin formation. There is no preserved evidence of the transient crater that would reveal the basin's maximum volume, but its diameter may now be inferred to be between 320 and 460 km. The gravity field resolves distinctive structures of Orientale's three rings and suggests the presence of faults associated with the outer two that penetrate to the mantle. The crustal structure of Orientale provides constraints on the formation of multiring basins.
Journal of undergraduate neuroscience education : JUNE : a publication of FUN, Faculty for Undergraduate Neuroscience, 2016
We describe the construction and use of a running wheel responsive to the movement of the earthwo... more We describe the construction and use of a running wheel responsive to the movement of the earthworm. The wheel employs readily available, inexpensive components and is easily constructed. Movement of the wheel can be monitored visually or via standard behavioral laboratory computer interfaces. Examples of data are presented, and possibilities for use in the teaching classroom are discussed.
With their large impact on the power system and widespread distribution, residential loads provid... more With their large impact on the power system and widespread distribution, residential loads provide vast resources that if utilized correctly have the potential to help reduce both electricity cost and demand throughout the day. Previous research in this area has been primarily focused on building more energy efficient homes and improving the efficiencies of appliances and lighting technologies. Far less attention has been given to
Stress, 2016
Sleep deprivation is associated with increased risk of myocardial infarction. However, it is unkn... more Sleep deprivation is associated with increased risk of myocardial infarction. However, it is unknown whether the effects of sleep deprivation are limited to increasing the likelihood of experiencing a myocardial infarction or if sleep deprivation also increases the extent of myocardial injury. In this study, rats were deprived of paradoxical sleep for 96 h using the platform-over-water method. Control rats were subjected to the same condition except the control platform was large enough for the rats to sleep. Hearts from sleep deprived and control rats were subjected to 20 min ischemia on a Langendorff isolated heart system. Infarct size and post ischemic recovery of contractile function were unaffected by sleep deprivation in male hearts. In contrast, hearts from sleep-deprived females exhibited significantly larger infarcts than hearts from control females. Post ischemic recovery of rate pressure product and + dP/dT were significantly attenuated by sleep deprivation in female hearts, and post ischemic recovery of end diastolic pressure was significantly elevated in hearts from sleep deprived females compared to control females, indicating that post ischemic recovery of both systolic and diastolic function were worsened by sleep deprivation. These data provide evidence that sleep deprivation increases the extent of ischemia-induced injury in a sex-dependent manner.
Biomaterials, 2015
The possibility of engineering the immune system in a targeted fashion using biomaterials such as... more The possibility of engineering the immune system in a targeted fashion using biomaterials such as nanoparticles has made considerable headway in recent years. However, little is known as to how modulating the spatial presentation of a ligand augments downstream immune responses. In this report we show that geometric manipulation of phosphatidylserine (PS) through fabrication on rod-shaped PLGA nanoparticles robustly dampens inflammatory responses from innate immune
Frontiers in Human Neuroscience, 2014
We introduced haptic cues to the serial reaction time (SRT) sequence learning task alongside the ... more We introduced haptic cues to the serial reaction time (SRT) sequence learning task alongside the standard visual cues to assess the relative contributions of visual and haptic stimuli to the formation of motor and perceptual memories. We used motorized keys to deliver brief pulse-like displacements to the resting fingers, expecting that the proximity and similarity of these cues to the subsequent response motor actions (finger-activated key-presses) would strengthen the motor memory trace in particular. We adopted the experimental protocol developed by Willingham (1999) to explore whether haptic cues contribute differently than visual cues to the balance of motor and perceptual learning. We found that sequence learning occurs with haptic stimuli as well as with visual stimuli and we found that irrespective of the stimuli (visual or haptic) the SRT task leads to a greater amount of motor learning than perceptual learning.
Nature, 2015
Chondrules are the millimetre-scale, previously molten, spherules found in most meteorites 1. Bef... more Chondrules are the millimetre-scale, previously molten, spherules found in most meteorites 1. Before chondrules formed, large differentiating planetesimals had already accreted 2. Volatile-rich olivine reveals that chondrules formed in extremely solid-rich environments, more like impact plumes than the solar nebula 3-5. The unique chondrules in CB chondrites probably formed in a vapour-melt plume produced by a hypervelocity impact 6 with an impact velocity greater than 10 kilometres per second. An acceptable formation model for the overwhelming majority of chondrules, however, has not been established. Here we report that impacts can produce enough chondrules during the first five million years of planetary accretion to explain their observed abundance. Building on a previous study of impact jetting 7 , we simulate protoplanetary impacts, finding that material is melted and ejected at high speed when the impact velocity exceeds 2.5 kilometres per second. Using a Monte Carlo accretion code, we estimate the location, timing, sizes, and velocities of chondrule-forming impacts. Ejecta size estimates 8 indicate that jetted melt will form millimetre-scale droplets. Our radiative transfer models show that these droplets experience the expected cooling rates of ten to a thousand kelvin per hour 9,10. An impact origin for chondrules implies that meteorites are a byproduct of planet formation rather than leftover building material. Recent work shows that the iSALE hydrocode 11,12 is capable of modelling the extreme process of impact jetting 7. While previous models focused on impacts between strengthless fluid bodies 7 , here we determine the effect that porosity and material strength have on the jetting process (Methods). Using iSALE we simulate vertical impacts of initially fractured dunite impactors of 1%, 10%, and 25% porosity and 10-km diameter on flat targets at impact velocity v imp 5 1-6 km s 21 stepping up by 0.5 km s 21 (Methods). Later, we scale our results to larger impactor sizes using hydrodynamic similarity 13. We find that no melted material (Methods) ejected above escape velocity is resolved for impacts with v imp , 2.5 km s 21 , assuming that v imp/ v esc is between 0.5 and 2, where v esc is the escape velocity. During the impact simulation shown in Fig. 1, a total mass of material equivalent to ,1% of the impactor's mass is melted and ejected at higher than escape velocity for an assumed v imp/ v esc 5 1. As shown in Fig. 1, jetting melts and ejects near-surface material at high velocity. Thermal modelling and palaeomagnetism of chondrites indicate that some differentiated planetesimals had outer shells of undifferentiated material 14. If this near-surface material is undifferentiated, jetting will produce chondrules with primitive compositions 15. This is in contrast to other models that rely on splashing during low-velocity (v imp < 10-100 m s 21) collisions between already molten planetesimals 16,17. It is doubtful that ejection of previously molten and differentiated 2 material would produce chemically unfractionated chondrules 18. Moreover, collisional splashing creates 'droplets' that are approximately 40 m in diameter (Methods). Previous size estimates 16 , which agreed with observed chondrule sizes, neglected the effect of decompression heating 19. Using the GAME Monte Carlo accretion code 20 we are able to determine where and when chondrule-forming impacts will occur. We model a typical minimum mass solar nebula (MMSN) and a three times more massive nebula (3MMSN), both of which extend from 0.4 astronomical units (AU) to 4 AU (ref. 20). Initially, solid bodies have a main-belt-like
Journal of Visualized Experiments, 2008
Journal of Visualized Experiments, 2008
Journal of Visualized Experiments, 2008
Glass Capillaries Reagent Sutter Instrument Co. BF150-86-10 Or, similar capillary glass. To make ... more Glass Capillaries Reagent Sutter Instrument Co. BF150-86-10 Or, similar capillary glass. To make filling the pipette easier, use a capillary with a glass filament.
Uploads
Papers by Brandon Johnson