Now showing items 21-40 of 66797

• #### The endoplasmic reticulum–resident E3 ubiquitin ligase Hrd1 controls a critical checkpoint in B cell development in mice

(AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC, 2018-08-17)
Humoral immunity involves multiple checkpoints that occur in B cell development, maturation, and activation. The pre-B-cell receptor (pre-BCR) is expressed following the productive recombination of the immunoglobulin heavy-chain gene, and sSignalsing through the pre-BCR are required for the differentiation of pre-B cells into immature B cells. However, the molecular mechanisms controlling the pre-BCR expression and signaling strength remain undefined. Herein, we probed the role of the endoplasmic reticulum-associated, stress-activated E3 ubiquitin ligase HMG-CoA reductase degradation 1 (Hrd1) in B cell differentiation. Using mice with a specific Hrd1 deletion in pro-B cells and subsequent B cell developmental stages, we showed that the E3 ubiquitin ligase Hrd1 governs a critical checkpoint during B cell development. We observed that Hrd1 is required for degradation of the pre-BCR complex during the early stage of B cell development. As a consequence, loss of Hrd1 in the B cell lineage resulted in increased pre-BCR expression levels and a developmental defect in the transition from large to small pre-B cells. This defect, in turn, resulted in reduced fewer mature B cells in bone marrow and peripheral lymphoid organs. Our results revealed a novel critical role of Hrd1 in controlling a critical checkpoint in B cell-mediated immunity and suggest that Hrd1 may functioning as an E3 ubiquitin ligase of the pre-BCR complex.
• #### Testing the white dwarf mass-radius relation and comparing optical and far-UV spectroscopic results with Gaia DR2, HST and FUSE

(OXFORD UNIV PRESS, 2018-09)
Observational tests of the white dwarf mass-radius relationship have always been limited by the uncertainty in the available distance measurements. Most studies have focused on Balmer line spectroscopy because these spectra can be obtained from ground-based observatories, while the Lyman lines are only accessible to space-based UV telescopes. We present results using parallax data from Gaia DR2 combined with space-based spectroscopy from HST and FUSE covering the Balmer and Lyman lines. We find that our sample supports the theoretical relation, although there is at least one star which is shown to be inconsistent. Comparison of results between Balmer and Lyman line spectra shows they are in agreement when the latest broadening tables are used. We also assess the factors which contribute to the error in the mass-radius calculations and confirm the findings of other studies which show that the spread in results for targets where multiple spectra are available is larger than the statistical error. The uncertainty in the spectroscopically derived log g parameter is now the main source of error rather than the parallax. Finally, we present new results for the radius and spectroscopic mass of Sirius B which agree with the dynamical mass and mass-radius relation within 1 sigma.
• #### Spin-Orbit-Torque Switching in 20-nm Perpendicular Magnetic Tunnel Junctions

(AMER PHYSICAL SOC, 2018-08-13)
Magnetization switching utilizing the spm-orbit torque of heavy metals is a promising alternative to spin-transfer torque for a faster and more energy-efficient write mechanism for magnetic random-access memory. We report spm-orbit-torque switching m 20-nm-diameter Co20Fe60B20-MgO-based perpendicular magnetic tunnel junctions with a thermal stability factor of similar to 47. Conductive atomic force microscopy was used to measure the tunnel magnetoresistance before and after current pulses through the heavy metal underlayer, and magnetostatic shifts m the minor loops provided evidence of spm-orbit-torque switching. Comparison of estimated critical current densities and write energies suggests that spm-orbit torque can be used as an effective switching mechanism for small and thermally stable perpendicular magnetic tunnel junctions.
• #### Spectroscopic Constraints on UV Metal Line Emission at z ≃ 6 − 9 The Nature of Lyα Emitting Galaxies in the Reionization-Era

(OXFORD UNIV PRESS, 2018-09)
Recent studies have revealed intense ultraviolet (UV) metal emission lines in a modest sample of z > 7 Lyman-alpha emitters, indicating a hard ionizing spectrum is present. If such high ionization features are shown to he common, it may indicate that extreme radiation fields play a role in regulating the visibility of Ly alpha in the reionization era. Here, we present deep near-infrared spectra of seven galaxies with Ly alpha, emission at 5.4 < z < 8.7 (including a newly confirmed lensed galaxy at z(Ly alpha) = 6.031) and three bright z similar or equal to 7 photometric targets. In nine sources, we do not detect UV metal lines. However in the z(Ly alpha) = 8.683 galaxy IEGSY8p7, we detect a 4.6 sigma emission line in the narrow spectral window expected for N v lambda 1243. The feature is unresolved (FWHM < 90 km s(-1)) and is likely nebular in origin. A deep H-band spectrum of FGSY8p7 reveals non-detections of C IV, He II, and O III], The presence of N v requires a substantial flux of photons above 77 eV, pointing to a hard ionizing spectrum powered by an active galactic nucleus or fast radiative shocks. Regardless of its origin, the intense radiation field of EGSY8p7 may aid the transmission of Ly alpha through what is likely a partially neutral intergalactic medium. With this new detection, live of 13 known Ly alpha emitters at z > 7 have now been shown to have intense UV line emission, suggesting that extreme radiation fields are commonplace among the Ly alpha population. Future observations with JWST will eventually clarify the origin of these features and explain their role in the visibility of Ly alpha, in the reionization era.
• #### SMHASH: anatomy of the Orphan Stream using RR Lyrae stars

(OXFORD UNIV PRESS, 2018-09)
Stellar tidal streams provide an opportunity to study the motion and structure of the disrupting galaxy as well as the gravitational potential of its host. Streams around the Milky Way are especially promising as phase space positions of individual stars will he measured by ongoing or upcoming surveys. Nevertheless, it remains a challenge to accurately assess distances to stars farther than 10 kpc from the Sun, where we have the poorest knowledge of the Galaxy's mass distribution. To address this, we present observations of 32 candidate RR Lyrae stars in the Orphan tidal stream taken as part of the Spitzer Merger History and Shape of the Galactic Halo (SMHASH) program. The extremely tight correlation between the periods, luminosities, and metallicities of RR Lyrae variable stars in the Spitzer IRAC 3.6 mu m band allows the determination of precise distances to individual stars; the median statistical relative distance uncertainty to each RR Lyrae star is 2.5 per cent. By fitting orbits in an example potential, we obtain an upper limit on the mass of the Milky Way interior to 60 kpc of 5.6(-1.1)(+1.2) x 10(11) M-circle dot, bringing estimates based on the Orphan Stream in line with those using other tracers. The SMHASH data also resolve the stream in line-of-sight depth, allowing a new perspective on the internal structure of the disrupted dwarf galaxy. Comparing with N body models, we find that the progenitor had an initial dark halo mass of approximately 3,2 x 10(9) M-circle dot, placing the Orphan Stream's progenitor amongst the classical dwarf spheroidals.
• #### Simpler, Faster, and Sensitive Zika Virus Assay Using Smartphone Detection of Loop-mediated Isothermal Amplification on Paper Microfluidic Chips

(NATURE PUBLISHING GROUP, 2018-08-20)
The recent Zika virus (ZIKV) outbreak has prompted the need for field-ready diagnostics that are rapid, easy-to-use, handheld, and disposable while providing extreme sensitivity and specificity. To meet this demand, we developed a wax-printed paper microfluidic chip utilizing reverse transcription loop-mediated isothermal amplification (RT-LAMP). The developed simple and sensitive ZIKV assay was demonstrated using undiluted tap water, human urine, and diluted (10%) human blood plasma. Paper type, pore size, and channel dimension of various paper microfluidic chips were investigated and optimized to ensure proper filtration of direct-use biological samples (tap water, urine, and plasma) during capillary action-driven flow. Once ZIKV RNA has flowed and reached to a detection area of the paper microfluidic chip, it was excised for the addition of an RT-LAMP mixture with a pH indicator, then placed on a hot plate at 68 degrees C. Visible color changes from successful amplification were observed in 15 minutes and quantified by smartphone imaging. The limit of detection was as low as 1 copy/mu L. The developed platform can also be used for identifying other flaviviruses, such as Chikungunya virus (CHIKV) and Dengue virus (DENV), and potentially other quickly transmitted virus pathogens, towards field-based diagnostics.
• #### Search for supersymmetry in events with four or more leptons in root s=13 TeV pp collisions with ATLAS

(AMER PHYSICAL SOC, 2018-08-15)
Results from a search for supersymmetry in events with four or more charged leptons (electrons, muons and taus) are presented. The analysis uses a data sample corresponding to 36.1 fb(-1) of proton-proton collisions delivered by the Large Hadron Collider at root s = 13 TeV and recorded by the ATLAS detector. Four-lepton signal regions with up to two hadronically decaying taus are designed to target a range of supersymmetric scenarios that can be either enriched in or depleted of events involving the production and decay of a Z boson. Data yields are consistent with Standard Model expectations and results are used to set upper limits on the event yields from processes beyond the Standard Model. Exclusion limits are set at the 95% confidence level in simplified models of general gauge mediated supersymmetry, where Higgsino masses are excluded up to 295 GeV. In R-parity-violating simplified models with decays of the lightest supersymmetric particle to charged leptons, lower limits of 1.46, 1.06, and 2.25 TeV are placed on wino, slepton and gluino masses, respectively.
• #### Search for pair production of heavy vector-like quarks decaying into high-(PT) W bosons and top quarks in the lepton-plus-jets final state in pp collisions at root s=13 TeV with the ATLAS detector

(SPRINGER, 2018-08-10)
A search is presented for the pair production of heavy vector-like B quarks, primarily targeting B quark decays into a W boson and a top quark. The search is based on 36.1 fb(-1) of pp collisions at root s = 13 TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Data are analysed in the lepton-plus-jets final state, characterised by a high-transverse-momentum isolated electron or muon, large missing transverse momentum, and multiple jets, of which at least one is b-tagged. No significant deviation from the Standard Model expectation is observed. The 95% confidence level lower limit on the B mass is 1350 GeV assuming a 100% branching ratio to Wt. In the SU(2) singlet scenario, the lower mass limit is 1170 GeV. The 100% branching ratio limits are found to be also applicable to heavy vector-like X production, with charge +5/3, that decay into Wt. This search is also sensitive to a heavy vector-like B quark decaying into other final states (Zb and Hb) and thus mass limits on B production are set as a function of the decay branching ratios.
• #### RELICS: Strong Lensing Analysis of the Galaxy Clusters Abell S295, Abell 697, MACS J0025.4-1222, and MACS J0159.8-0849

(IOP PUBLISHING LTD, 2018-08-20)
We present a strong lensing analysis of four massive galaxy clusters imaged with the Hubble Space Telescope in the Reionization Lensing Cluster Survey. We use a light-traces-mass technique to uncover sets of multiple images and constrain the mass distribution of the clusters. These mass models are the first published for Abell S295 and MACS J0159.8-0849 and are improvements over previous models for Abell 697 and MACS J0025.4-1222. Our analysis for MACS J0025.4-1222 and Abell S295 shows a bimodal mass distribution supporting the merger scenarios proposed for these clusters. The updated model for MACS J0025.4-1222 suggests a substantially smaller critical area than previously estimated. For MACS J0159.8-0849 and Abell 697, we find a single peak and relatively regular morphology revealing fairly relaxed clusters. Despite being less prominent lenses, three of these clusters seem to have lensing strengths, i.e., cumulative area above certain magnification, similar to those of the Hubble Frontier Fields clusters (e.g., A(mu > 5) similar to 1-3 arcmin(2), A(mu > 10) similar to 0.5-1.5 arcmin(2)), which in part can be attributed to their merging configurations. We make our lens models publicly available through the Mikulski Archive for Space Telescopes. Finally, using Gemini-N/GMOS spectroscopic observations, we detect a single emission line from a high-redshift J(125) similar or equal to 25.7 galaxy candidate lensed by Abell 697. While we cannot rule out a lower-redshift solution, we interpret the line as Ly alpha at z = 5.800 +/- 0.001, in agreement with its photometric redshift and dropout nature. Within this scenario, we measure a Lya rest-frame equivalent width of 52 +/- 22 angstrom and an observed Gaussian width of 117 +/- 15 km s(-1).
• #### Model-independent Test of the Cosmic Distance Duality Relation

(IOP PUBLISHING LTD, 2018-10-08)
A validation of the cosmic distance duality (CDD) relation, h() ( ) () () z zdz dz º+ = 1 A L 1 2 , coupling the luminosity (dL) and angular-diameter (dA) distances, is crucial because its violation would require exotic new physics. We present a model-independent test of the CDD, based on strong lensing and a reconstruction of the H II galaxy Hubble diagram using Gaussian processes, to confirm the validity of the CDD at a very high level of confidence. Using parameterizations h( )z z = +1 h0 and h( )z zz =+ + 1 h h 1 2 2, our best-fit results are h = - + 0.0147 0 0.066 0.056, and h = - + 0.1091 1 0.1568 0.1680 and h = - - + 0.0603 2 0.0988 0.0999, respectively. In spite of these strong constraints, however, we also point out that the analysis of strong lensing using a simplified single isothermal sphere (SIS) model for the lens produces some irreducible scatter in the inferred CDD data. The use of an extended SIS approximation, with a power-law density structure, yields very similar results, but does not lessen the scatter due to its larger number of free parameters, which weakens the best-fit constraints. Future work with these strong lenses should therefore be based on more detailed ray-tracing calculations to determine the mass distribution more precisely
• #### RELICS: A Strong Lens Model for SPT-CLJ0615-5746, a z=0.972 Cluster

(IOP PUBLISHING LTD, 2018-08-20)
We present a lens model for the cluster SPT-CLJ0615-5746, which is the highest-redshift (z = 0.972) system in the Reionization of Lensing Clusters Survey, making it the highest-redshift cluster for which a full, strong lens model is published. We identify three systems of multiply imaged lensed galaxies, two of which we spectroscopically confirm at z = 1.358 and z = 4.013, which we use as constraints for the model. We find a foreground structure at z similar to 0.4, which we include as a second cluster-sized halo in one of our models; however, two different statistical tests find the best-fit model consists of one cluster-sized halo combined with three individually optimized galaxy-sized halos, as well as contributions from the cluster galaxies themselves. We find the total projected mass density within r = 26.'' 7 (the region where the strong lensing constraints exist) to be M = 2.51(-0.09)(+0.15) x 10(14) M-circle dot. If we extrapolate out to r(500), our projected mass density is consistent with the mass inferred from weak lensing and from the Sunyaev-Zel'dovich effect (M similar to 10(15)M(circle dot)). This cluster is lensing a previously reported z similar to 10 galaxy, which, if spectroscopically confirmed, will be the highest-redshift strongly lensed galaxy known.
• #### Cosmological tests with the joint lightcurve analysis

(EPL ASSOCIATION, 2018-10-05)
We examine whether a comparison between wCDM and $R_{\textrm{h}}=ct$ using merged Type-Ia SN catalogs produces results consistent with those based on a single homogeneous sample. Using the Betoule et al. (Astron. Astrophys., 568 (2014) 22). Joint Lightcurve Analysis (JLA) of a combined sample of 613 events from SNLS and SDSS-II, we estimate the parameters of the two models and compare them. We find that the improved statistics can alter the model selection in some cases, but not others. In addition, based on the model fits, we find that there appears to be a lingering systematic offset of ~0.04–0.08 mag between the SNLS and SDSS-II sources, in spite of the cross-calibration in the JLA. Treating wCDM, ΛCDM and $R_{\textrm{h}}=ct$ as separate models, we find in an unbiased pairwise statistical comparison that the Bayes Information Criterion (BIC) favors the $R_{\textrm{h}}=ct$ Universe with a likelihood of $82.8\%$ vs. $17.2\%$ for wCDM, but the ratio of likelihoods is reversed ($16.2\%$ vs. $83.8\%$ ) when $w_{\textrm{de}}=-1$ (i.e., ΛCDM) and strongly reversed ($1.0\%$ vs. $99.0\%$ ) if in addition k = 0 (i.e., flat ΛCDM). We point out, however, that the value of k is a measure of the net energy (kinetic plus gravitational) in the Universe and is not constrained theoretically, though some models of inflation would drive $k\rightarrow 0$ due to an expansion-enforced dilution. Since we here consider only the basic ΛCDM model, the value of k needs to be measured and, therefore, the pre-assumption of flatness introduces a significant bias into the BIC.
• #### Model selection using cosmic chronometers with Gaussian Processes

(2018-02-19)
The use of Gaussian Processes with a measurement of the cosmic expansion rate based solely on the observation of cosmic chronometers provides a completely cosmology-independent reconstruction of the Hubble constant H(z) suitable for testing different models. The corresponding dispersion σH is smaller than ~ 9% over the entire redshift range (lesssim zlesssim 20) of the observations, rivaling many kinds of cosmological measurements available today. We use the reconstructed H(z) function to test six different cosmologies, and show that it favours the Rh=ct universe, which has only one free parameter (i.e., H0) over other models, including Planck ΛCDM . The parameters of the standard model may be re-optimized to improve the fits to the reconstructed H(z) function, but the results have smaller p-values than one finds with Rh=ct.
• #### Quit outcomes among clients ineligible for cessation medication through the state quitline: a retrospective, observational study

(BMC, 2018-08-10)
Background: Distribution of tobacco cessation medications through state quitlines increases service utilization and quit outcomes. However, some state quitlines have moved to models in which callers are instructed to obtain quit medications through their health insurance pharmaceutical benefit. We aimed to investigate the impact of this policy on medication access and quit outcomes in the state quitline setting for clients who must obtain covered medications through the state Medicaid program. We hypothesized that clients with Medicaid who were referred by their healthcare provider would be more likely to report using quit medication and have higher quit rates compared to clients with Medicaid who engaged the quitline on their own. Methods: An observational, retrospective study was conducted using state quitline clients with Medicaid health insurance who were ineligible for quitline provided cessation medications. Clients were stratified by referral type: self-referred, passively referred, and proactively referred. Unadjusted and adjusted logistic regression was used to estimate the effect of referral type on both quit status and cessation medication use. Results: Proactively referred clients were less likely to use quit medication (53.6%) compared to self (56.9%) and passively referred clients (61.1%). Proactively referred clients had lower quit rates (31.4%), as compared to passively referred (36.0%) and self-referred (35.1%). In adjusted models, proactively referred clients were significantly less likely to be quit than passively referred clients (OR = 0.75, 95% CI: 0.56, 0.99). There were no statistically significant differences in medication use or number of coaching sessions among proactive, passive, and self-referred clients in adjusted models. Conclusions: In adjusted models, medication use did not significantly differ by mode of entry in this population of Medicaid beneficiaries. Psychosocial factors such as intention to quit in the next 30 days, social support for quitting, education level, race, and ethnicity impacted quit status and differed by mode of entry. Quitlines should use tailored strategies to increase engagement and reduce barriers among proactively referred clients.
• #### Principal Component Analysis as a Tool for Characterizing Black Hole Images and Variability

(IOP PUBLISHING LTD, 2018-09-01)
We explore the use of principal component analysis (PCA) to characterize high-fidelity simulations and interferometric observations of the millimeter emission that originates near the horizons of accreting black holes. We show mathematically that the Fourier transforms of eigenimages derived from PCA applied to an ensemble of images in the spatial domain are identical to the eigenvectors of PCA applied to the ensemble of the Fourier transforms of the images, which suggests that this approach may be applied to modeling the sparse interferometric Fourier-visibilities produced by an array such as the Event Horizon Telescope. We also show that the simulations in the spatial domain can themselves be compactly represented with a PCA-derived basis of eigenimages, which allows for detailed comparisons to be made between variable observations and time-dependent models, as well as for detection of outliers or rare events within a time series of images. Furthermore, we demonstrate that the spectrum of PCA eigenvalues is a diagnostic of the power spectrum of the structure and, hence, of the underlying physical processes in the simulated and observed images.
• #### Physical properties and H-ionizing-photon production rates of extreme nearby star-forming regions

(OXFORD UNIV PRESS, 2018-09)
Measurements of the galaxy UV luminosity function at z greater than or similar to 6 suggest that young stars hosted in low-mass star-forming galaxies produced the bulk of hydrogen-ionizing photons necessary to reionize the intergalactic medium (IGM) by redshift z similar to 6. Whether star-forming galaxies dominated cosmic reionization, however, also depends on their stellar populations and interstellar medium properties, which set, among other things, the production rate of H-ionizing photons,. xi(star)(ion), and the fraction of these escaping into the IGM. Given the difficulty of constraining with existing observatories the physical properties of z greater than or similar to 6 galaxies, in this work we focus on a sample of 10 nearby objects showing UV spectral features comparable to those observed at z greater than or similar to 6. We use the new-generation BEAGLE tool to model the UV-to-optical photometry and UV/optical emission lines of these local 'analogues' of high-redshift galaxies, finding that our relatively simple, yet fully self-consistent, physical model can successfully reproduce the different observables considered. Our galaxies span a broad range of metallicities and are characterized by high ionization parameters, low dust attenuation, and very young stellar populations. Through our analysis, we derive a novel diagnostic of the production rate of H-ionizing photons per unit UV luminosity,. xi(star)(ion), based on the equivalent width of the bright [O III] lambda lambda 4959,5007 line doublet, which does not require measurements of H-recombination lines. This new diagnostic can be used to estimate. xi(star)(ion) from future direct measurements of the [OIII] lambda lambda 4959,5007 line using JWST/NIRSpec (out to z similar to 9.5), and by exploiting the contamination by H, ss + [O III] lambda lambda 4959,5007 of photometric observations of distant galaxies, for instance from existing Spitzer/IRAC data and from future ones with JWST/NIRCam.
• #### Pharmacy Competencies for Interprofessional Integrative Health Care Education.

(AMER ASSOC COLL PHARMACY, 2018-08-01)
Objective. To address the gap in evidence-based knowledge among pharmacy students and practicing pharmacists regarding complementary and integrative health approaches due to insufficient education and a lack of standardized training. Methods. The National Center for Integrative Primary Healthcare (NCIPH) developed 22 pharmacy competencies linked to a set of 10 interprofessional "metacompetencies" in integrative health care. Results. The NCIPH pharmacy competencies are well-aligned with the current educational standards and Center for the Advancement of Pharmacy Education (CAPE) outcomes for pharmacy programs. Therefore, the NCIPH competencies may provide a foundation for the incorporation of interprofessional integrative health care education into pharmacy curricula. Conclusion. The NCIPH pharmacy competencies in integrative health care, linked to the interprofessional "metacompetencies," are aligned with educational standards and outcomes, and may serve as a basis for pharmacy curriculum.
• #### Optical binding of two cooled micro-gyroscopes levitated in vacuum

(OPTICAL SOC AMER, 2018-08-20)
Coupling between mesoscopic particles levitated in vacuum is a prerequisite for the realization of a large-scale array of particles in an underdamped environment as well as potential studies at the classical - quantum interface. Here, we demonstrate for the first time, to the best of our knowledge, optical binding between two rotating microparticles mediated by light scattering in vacuum. We investigate autocorrelations between the two normal modes of oscillation determined by the center-of-mass and the relative positions of the two-particle system. The inter-particle coupling, as a consequence of optical binding, removes the degeneracy of the normal mode frequencies, which is in good agreement with theory. We further demonstrate that the optically bound array of rotating microparticles retains their optical coupling during gyroscopic cooling, and exhibits cooperative motion whose center-of-mass is stabilized.
• #### A solution to the electroweak horizon problem in the $$R_\mathrm{h}=ct$$Rh=ct universe

(SPRINGER, 2018-09)
Particle physics suggests that the Universe may have undergone several phase transitions, including the well- known inflationary event associated with the separation of the strong and electroweak forces in grand unified theories. The accelerated cosmic expansion during this transition, at cosmic time t ∼ 10−36 − 10−33 s, is often viewed as an explanation for the uniformity of the CMB temperature, T , which would otherwise have required inexplicable initial conditions. With the discovery of the Higgs particle, it is now quite likely that the Universe underwent another (elec- troweak) phase transition, at T = 159.5 ± 1.5 GeV – roughly ∼ 10−11 s after the big bang. During this event, the fermions gained mass and the electric force separated from the weak force. There is currently no established explanation, however, for the apparent uniformity of the vacuum expectation value of the Higgs field which, like the uniformity in T , gives rise to its own horizon problem in standard ΛCDM cosmology. We show in this paper that a solution to the electroweak horizon problem may be found in the choice of cosmological model, and demonstrate that this issue does not exist in the alterna- tive Friedmann–Robertson–Walker cosmology known as the Rh = ct universe.
• #### Cloud-resolving model intercomparison of an MC3E squall line case: Part I-Convective updrafts

(AMER GEOPHYSICAL UNION, 2017-09-16)
An intercomparison study of a midlatitude mesoscale squall line is performed using the Weather Research and Forecasting (WRF) model at 1 km horizontal grid spacing with eight different cloud microphysics schemes to investigate processes that contribute to the large variability in simulated cloud and precipitation properties. All simulations tend to produce a wider area of high radar reflectivity (Z(e) > 45 dBZ) than observed but a much narrower stratiform area. The magnitude of the virtual potential temperature drop associated with the gust front passage is similar in simulations and observations, while the pressure rise and peak wind speed are smaller than observed, possibly suggesting that simulated cold pools are shallower than observed. Most of the microphysics schemes overestimate vertical velocity and Z(e) in convective updrafts as compared with observational retrievals. Simulated precipitation rates and updraft velocities have significant variability across the eight schemes, even in this strongly dynamically driven system. Differences in simulated updraft velocity correlate well with differences in simulated buoyancy and low-level vertical perturbation pressure gradient, which appears related to cold pool intensity that is controlled by the evaporation rate. Simulations with stronger updrafts have a more optimal convective state, with stronger cold pools, ambient low-level vertical wind shear, and rear-inflow jets. Updraft velocity variability between schemes is mainly controlled by differences in simulated ice-related processes, which impact the overall latent heating rate, whereas surface rainfall variability increases in no-ice simulations mainly because of scheme differences in collision-coalescence parameterizations.