Book Review: A Comparative Handbook to the Gospel of Mark

Review of A Comparative Handbook to the Gospel of Mark: Comparisons with Pseudepigrapha, the Qumran Scrolls, and Rabbinic Literature, edited by Bruce Chilton, Darrell Bock, Daniel M Gurtner, Jacob Neusner, Lawrence H. Schiffman, and Daniel Oden. Leiden: Brill, 2010

Examination of an inverted repeat within the F factor origin of transfer: context dependence of F TraI relaxase DNA specificity

Prior to conjugative transfer of plasmids, one plasmid strand is cleaved in a site- and strand-specific manner by an enzyme called a relaxase or nickase. In F and related plasmids, an inverted repeat is located near the plasmid strand cleavage site, and others have proposed that the ability of this sequence to form a hairpin when in single-stranded form is important for transfer. Substitutions were introduced into a cloned F oriT region and their effects on plasmid transfer were assessed. For those substitutions that substantially reduced transfer, the results generally correlated with effects on in vitro binding of oligonucleotides to the F TraI relaxase domain rather than with predicted effects on hairpin formation. One substitution shown previously to dramatically reduce both plasmid transfer and in vitro binding to a 17-base oligonucleotide had little apparent effect on binding to a 30-base oligonucleotide that contained the hairpin region. Results from subsequent experiments strongly suggest that the relaxase domain can bind to hairpin oligonucleotides in two distinct manners with different sequence specificities, and that the protein binds the oligonucleotides at the same or overlapping sites

Maintenance of viral suppression in HIV-1–infected HLA-B*57+ elite suppressors despite CTL escape mutations

Rare human immunodeficiency virus 1–infected individuals, termed elite suppressors (ES), maintain plasma virus levels of <50 copies/ml and normal CD4 counts without therapy. The major histocompatibility complex class I allele group human histocompatibility leukocyte antigen (HLA)-B*57 is overrepresented in this population. Mutations in HLA-B*57–restricted epitopes have been observed in ES, but their significance has remained unclear. Here we investigate the extent and impact of cytotoxic T lymphocyte (CTL) escape mutations in HLA-B*57+ ES. We provide the first direct evidence that most ES experience chronic low level viremia. Sequencing revealed a striking discordance between the genotypes of plasma virus and archived provirus in resting CD4+ T cells. Mutations in HLA-B*57–restricted Gag epitopes were present in all viruses from plasma but were rare in proviruses, suggesting powerful selective pressure acting at these epitopes. Surprisingly, strong CD8+ T cell interferon-γ responses were detected against some mutant epitopes found in plasma virus, suggesting the development of de novo responses to viral variants. In some individuals, relative CD8+ T cell interleukin-2 responses showed better correlation with the selection observed in vivo. Thus, analysis of low level viremia reveals an unexpectedly high level of CTL escape mutations reflecting selective pressure acting at HLA-B*57–restricted epitopes in ES. Continued viral suppression probably reflects CTL responses against unmutated epitopes and residual or de novo responses against epitopes with escape mutations

Using Community-Based Programming to Increase Family Social Support for Healthy Eating among African American Adolescents

Little is known about emotional and instrumental social support for nutrition behaviors among African-American adolescents. In this paper, we specifically examine intervention effects on emotional, instrumental and total (composite) social support for fruit/vegetable and low-fat dairy intake. Data from a larger intervention, based on Social Cognitive Theory, which was implemented with 38 African-American adolescents and their families to increase fruit/vegetable intake, low-fat dairy intake and physical activity behaviors are presented. One-way ANOVA analyses revealed that intervention participants had positive and significant increases in emotional social support for low-fat dairy intake (P=0.01), total social support for fruit/vegetable intake (P=0.05), and total social support for low-fat dairy intake (P=0.02). Specific recommendations addressing family social support for healthy eating through youth development programming are discussed

Hematopoietic stem cell transplantation and vasculopathy associated with STAT3-dominant-negative hyper-IgE syndrome

Dominant negative mutations in the transcription-factor STAT3 underlie the rare primary immunodeficiency Job's syndrome. Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) has shown promise in correction of the underlying immunological defect, with one report suggesting HSCT can prevent development of wider connective tissue complications. Here, we report the case of a 26 year old male who developed an acute ST-elevation myocardial infarction due to coronary artery ectasia and thrombosis, occurring despite pediatric allogeneic HSCT for STAT3-HIES and a predicted 10-year conventional cardiovascular risk of 0.1%. Vasculopathy associated with STAT3-HIES may persist or arise following HSCT and can precipitate life-threatening complications. This has implications for counseling and vascular surveillance, and highlights the need for further studies to determine the risk, pathogenesis, and optimal management of the vasculopathy associated with STAT3-HIES

Mapping our Universe in 3D with MITEoR

Mapping our universe in 3D by imaging the redshifted 21 cm line from neutral hydrogen has the potential to overtake the cosmic microwave background as our most powerful cosmological probe, because it can map a much larger volume of our Universe, shedding new light on the epoch of reionization, inflation, dark matter, dark energy, and neutrino masses. We report on MITEoR, a pathfinder low-frequency radio interferometer whose goal is to test technologies that greatly reduce the cost of such 3D mapping for a given sensitivity. MITEoR accomplishes this by using massive baseline redundancy both to enable automated precision calibration and to cut the correlator cost scaling from N^2 to NlogN, where N is the number of antennas. The success of MITEoR with its 64 dual-polarization elements bodes well for the more ambitious HERA project, which would incorporate many identical or similar technologies using an order of magnitude more antennas, each with dramatically larger collecting area.Comment: To be published in proceedings of 2013 IEEE International Symposium on Phased Array Systems & Technolog

Resolving Decades of Periodic Spirals from the Wolf-Rayet Dust Factory WR 112

WR 112 is a dust-forming carbon-rich Wolf-Rayet (WC) binary with a dusty circumstellar nebula that exhibits a complex asymmetric morphology, which traces the orbital motion and dust formation in the colliding winds of the central binary. Unraveling the complicated circumstellar dust emission around WR 112 therefore provides an opportunity to understand the dust formation process in colliding-wind WC binaries. In this work, we present a multi-epoch analysis of the circumstellar dust around WR 112 using seven high spatial resolution (FWHM $\sim0.3-0.4''$) N-band ($\lambda \sim12$ $\mu$m) imaging observations spanning almost 20 years and includes newly obtained images from Subaru/COMICS in Oct 2019. In contrast to previous interpretations of a face-on spiral morphology, we observe clear evidence of proper motion of the circumstellar dust around WR 112 consistent with a nearly edge-on spiral with a $\theta_s=55^\circ$ half-opening angle and a $\sim20$-yr period. The revised near edge-on geometry of WR 112 reconciles previous observations of highly variable non-thermal radio emission that was inconsistent with a face-on geometry. We estimate a revised distance to WR 112 of $d = 3.39^{+0.89}_{-0.84}$ kpc based on the observed dust expansion rate and a spectroscopically derived WC terminal wind velocity of $v_\infty= 1230\pm260$ km s$^{-1}$. With the newly derived WR 112 parameters we fit optically-thin dust spectral energy distribution models and determine a dust production rate of $\dot{M}_d=2.7^{+1.0}_{-1.3}\times10^{-6}$ M$_\odot$ yr$^{-1}$, which demonstrates that WR 112 is one of the most prolific dust-making WC systems known.Comment: 17 pages, 9 figures, 1 animated gif, accepted for publication in Ap

L-Edge Spectroscopy of Dilute, Radiation-Sensitive Systems Using a Transition-Edge-Sensor Array

We present X-ray absorption spectroscopy and resonant inelastic X-ray scattering (RIXS) measurements on the iron L-edge of 0.5 mM aqueous ferricyanide. These measurements demonstrate the ability of high-throughput transition-edge-sensor (TES) spectrometers to access the rich soft X-ray (100-2000eV) spectroscopy regime for dilute and radiation-sensitive samples. Our low-concentration data are in agreement with high-concentration measurements recorded by conventional grating-based spectrometers. These results show that soft X-ray RIXS spectroscopy acquired by high-throughput TES spectrometers can be used to study the local electronic structure of dilute metal-centered complexes relevant to biology, chemistry and catalysis. In particular, TES spectrometers have a unique ability to characterize frozen solutions of radiation- and temperature-sensitive samples.Comment: 19 pages, 4 figure