11,609 research outputs found
Subclinical infection of macaques and baboons with a baboon simarterivirus
Simarteriviruses (Arteriviridae: Simarterivirinae) are commonly found at high titers in the blood of African monkeys but do not cause overt disease in these hosts. In contrast, simarteriviruses cause severe disease in Asian macaques upon accidental or experimental transmission. Here, we sought to better understand the host-dependent drivers of simarterivirus pathogenesis by infecting olive baboons (n = 4) and rhesus monkeys (n = 4) with the simarterivirus Southwest baboon virus 1 (SWBV-1). Surprisingly, none of the animals in our study showed signs of disease following SWBV-1 inoculation. Three animals (two rhesus monkeys and one olive baboon) became infected and sustained high levels of SWBV-1 viremia for the duration of the study. The course of SWBV-1 infection was highly predictable: plasma viremia peaked between 1 × 107 and 1 × 108 vRNA copies/mL at 3–10 days post-inoculation, which was followed by a relative nadir and then establishment of a stable set-point between 1 × 106 and 1 × 107 vRNA copies/mL for the remainder of the study (56 days). We characterized cellular and antibody responses to SWBV-1 infection in these animals, demonstrating that macaques and baboons mount similar responses to SWBV-1 infection, yet these responses are ineffective at clearing SWBV-1 infection. SWBV-1 sequencing revealed the accumulation of non-synonymous mutations in a region of the genome that corresponds to an immunodominant epitope in the simarterivirus major envelope glycoprotein GP5, which likely contribute to viral persistence by enabling escape from host antibodies
Spatial Effects and GWA Mapping of Root Colonization Assessed in the Interaction Between the Rice Diversity Panel 1 and an Arbuscular Mycorrhizal Fungus
The majority of the research reported here is an output of EU project “EURoot” (FP7-KBBE-2011-5 Grant Agreement No. 289300) project. RS’s contribution was funded by FACCE-JPI NET project “GreenRice” (Sustainable and environmental friendly rice cultivation systems in Europe) and was funded by the BBSRC award BB/M018415/1.Peer reviewedPublisher PD
ALMA Resolves 30 Doradus: Sub-parsec Molecular Cloud Structure Near the Closest Super-Star Cluster
We present ALMA observations of 30 Doradus -- the highest resolution view of
molecular gas in an extragalactic star formation region to date (~0.4pc x
0.6pc). The 30Dor-10 cloud north of R136 was mapped in 12CO 2-1, 13CO 2-1, C18O
2-1, 1.3mm continuum, the H30alpha recombination line, and two H2CO 3-2
transitions. Most 12CO emission is associated with small filaments and clumps
(<1pc, ~1000 Msun at the current resolution). Some clumps are associated with
protostars, including "pillars of creation" photoablated by intense radiation
from R136. Emission from molecular clouds is often analyzed by decomposition
into approximately beam-sized clumps. Such clumps in 30 Doradus follow similar
trends in size, linewidth, and surface density to Milky Way clumps. The 30
Doradus clumps have somewhat larger linewidths for a given size than predicted
by Larson's scaling relation, consistent with pressure confinement. They extend
to higher surface density at a given size and linewidth compared to clouds
studied at 10pc resolution. These trends are also true of clumps in Galactic
infrared-dark clouds; higher resolution observations of both environments are
required. Consistency of clump masses calculated from dust continuum, CO, and
the virial theorem reveals that the CO abundance in 30 Doradus clumps is not
significantly different from the LMC mean, but the dust abundance may be
reduced by ~2. There are no strong trends in clump properties with distance
from R136; dense clumps are not strongly affected by the external radiation
field, but there is a modest trend towards lower dense clump filling fraction
deeper in the cloud.Comment: accepted to Ap
Influence of dna repair on nonlinear dose-responses for mutation
Recent evidence has challenged the default assumption that all DNA-reactive alkylating agents exhibit a linear dose-response. Emerging evidence suggests that the model alkylating agents methyl- and ethylmethanesulfonate and methylnitrosourea (MNU) and ethylnitrosourea observe a nonlinear dose-response with a no observed genotoxic effect level (NOGEL). Follow-up mechanistic studies are essential to understand the mechanism of cellular tolerance and biological relevance of such NOGELs. MNU is one of the most mutagenic simple alkylators. Therefore, understanding the mechanism of mutation induction, following low-dose MNU treatment, sets precedence for weaker mutagenic alkylating agents. Here, we tested MNU at 10-fold lower concentrations than a previous study and report a NOGEL of 0.0075μg/ml (72.8nM) in human lymphoblastoid cells, quantified through the hypoxanthine (guanine) phosphoribosyltransferase assay (OECD 476). Mechanistic studies reveal that the NOGEL is dependent upon repair of O6-methylguanine (O6MeG) by the suicide enzyme O6MeG-DNA methyltransferase (MGMT). Inactivation of MGMT sensitizes cells to MNU-induced mutagenesis and shifts the NOGEL to the left on the dose axis. © The Author 2013. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved
At what age do normal weight Canadian children become overweight adults? Differences according to sex and metric
Background: The prevalence of overweight and obesity doubles between adolescence and young adulthood. However, the exact age, and appropriate metric to use, to identify when overweight develops is still debated. Aim: To examine the age of onset of overweight by sex and four metrics: body mass index (BMI), fat mass (%FM), waist circumference (WC) and waist-to-height ratio (WHtR). Methods: Between 1991 and 2017, serial measures of body composition, were taken on 237 (108 males) individuals (aged 8 to 40 years of age). Hierarchical random effects models were used to develop growth curves. Curves were compared to BMI, %FM and WC overweight age and sex-specific cut-points. Results: In males the BMI growth curve crossed the cut-point at 22.0 years compared to 23.5 and 26.5 years for WHtR and %FM respectively; WC cut-off were not reached until 36 years. In females the BMI growth curve, crossed the overweight cut-point at 21.5 years compared to 14.2 years for %FM and at 21.9 and 27.5 years for WC and WHtR respectively. Conclusions: Overweight onset occurs during young adulthood with the exception of WC in males. BMI in males and %FM in females were the metric identifying overweight the earliest
CARMA Measurements of the Sunyaev-Zel'dovich Effect in RXJ1347.5-1145
We demonstrate the Sunyaev-Zel'dovich (SZ) effect imaging capabilities of the
Combined Array for Research in Millimeter-wave Astronomy (CARMA) by presenting
an SZ map of the galaxy cluster RXJ1347.5-1145. By combining data from multiple
CARMA bands and configurations, we are able to capture the structure of this
cluster over a wide range of angular scales, from its bulk properties to its
core morphology. We find that roughly 9% of this cluster's thermal energy is
associated with sub-arcminute-scale structure imparted by a merger,
illustrating the value of high-resolution SZ measurements for pursuing cluster
astrophysics and for understanding the scatter in SZ scaling relations. We also
find that the cluster's SZ signal is lower in amplitude than suggested by a
spherically-symmetric model derived from X-ray data, consistent with
compression along the line of sight relative to the plane of the sky. Finally,
we discuss the impact of upgrades currently in progress that will further
enhance CARMA's power as an SZ imaging instrument.Comment: 8 pages, 6 figure
Geographic Information System Data Analysis
Data was collected in order to further NASA Langley Research Center's Geographic Information System(GIS). Information on LaRC's communication, electrical, and facility configurations was collected. Existing data was corrected through verification, resulting in more accurate databases. In addition, Global Positioning System(GPS) points were used in order to accurately impose buildings on digitized images. Overall, this project will help the Imaging and CADD Technology Team (ICTT) prove GIS to be a valuable resource for LaRC
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