124 research outputs found
Supervoid Origin of the Cold Spot in the Cosmic Microwave Background
We use a WISE-2MASS-Pan-STARRS1 galaxy catalog to search for a supervoid in
the direction of the Cosmic Microwave Background Cold Spot. We obtain
photometric redshifts using our multicolor data set to create a tomographic map
of the galaxy distribution. The radial density profile centred on the Cold Spot
shows a large low density region, extending over 10's of degrees. Motivated by
previous Cosmic Microwave Background results, we test for underdensities within
two angular radii, , and . Our data, combined with an
earlier measurement by Granett et al 2010, are consistent with a large supervoid with centered at . Such a supervoid, constituting a
fluctuation in the model, is a plausible cause
for the Cold Spot.Comment: 4 pages, 2 figures, Proceedings of IAU 306 Symposium: Statistical
Challenges in 21st Century Cosmolog
Drivers of Tuberculosis Transmission.
Measuring tuberculosis transmission is exceedingly difficult, given the remarkable variability in the timing of clinical disease after Mycobacterium tuberculosis infection; incident disease can result from either a recent (ie, weeks to months) or a remote (ie, several years to decades) infection event. Although we cannot identify with certainty the timing and location of tuberculosis transmission for individuals, approaches for estimating the individual probability of recent transmission and for estimating the fraction of tuberculosis cases due to recent transmission in populations have been developed. Data used to estimate the probable burden of recent transmission include tuberculosis case notifications in young children and trends in tuberculin skin test and interferon γ-release assays. More recently, M. tuberculosis whole-genome sequencing has been used to estimate population levels of recent transmission, identify the distribution of specific strains within communities, and decipher chains of transmission among culture-positive tuberculosis cases. The factors that drive the transmission of tuberculosis in communities depend on the burden of prevalent tuberculosis; the ways in which individuals live, work, and interact (eg, congregate settings); and the capacity of healthcare and public health systems to identify and effectively treat individuals with infectious forms of tuberculosis. Here we provide an overview of these factors, describe tools for measurement of ongoing transmission, and highlight knowledge gaps that must be addressed
Zoonotic tuberculosis in human beings caused by Mycobacterium bovis—a call for action
Mycobacterium tuberculosis is recognised as the primary cause of human tuberculosis worldwide. However, substantial evidence suggests that the burden of Mycobacterium bovis, the cause of bovine tuberculosis, might be underestimated in human beings as the cause of zoonotic tuberculosis. In 2013, results from a systematic review and meta-analysis of global zoonotic tuberculosis showed that the same challenges and concerns expressed 15 years ago remain valid. These challenges faced by people with zoonotic tuberculosis might not be proportional to the scientific attention and resources allocated in recent years to other diseases. The burden of zoonotic tuberculosis in people needs important reassessment, especially in areas where bovine tuberculosis is endemic and where people live in conditions that favour direct contact with infected animals or animal products. As countries move towards detecting the 3 million tuberculosis cases estimated to be missed annually, and in view of WHO's end TB strategy endorsed by the health authorities of WHO Member States in 2014 to achieve a world free of tuberculosis by 2035, we call on all tuberculosis stakeholders to act to accurately diagnose and treat tuberculosis caused by M bovis in human beings
The Cold Spot in the Cosmic Microwave Background: the Shadow of a Supervoid
Standard inflationary hot big bang cosmology predicts small
fluctuations in the Cosmic Microwave Background (CMB) with
isotropic Gaussian statistics. All measurements support the
standard theory, except for a few anomalies discovered in the
Wilkinson Microwave Anisotropy Probe maps and confirmed recently
by the Planck satellite. The Cold Spot is one of the most
significant of such anomalies, and the leading explanation of it
posits a large void that imprints this extremely cold area via
the linear Integrated Sachs-Wolfe (ISW) effect due to the decay
of gravitational potentials over cosmic time, or via the Rees-
Sciama (RS) effect due to late-time non-linear evolution.
Despite several observational campaigns targeting the Cold Spot
region, to date no suitably large void was found at higher
redshifts z>0.3. Here we report the detection of an R=(192±15)h
−1Mpc size supervoid of depth δ=−0.13±0.03, and centred at
redshift z=0.22. This supervoid, possibly the largest ever
found, is large enough to significantly affect the CMB via the
non-linear RS effect, as shown in our Lemaitre-Tolman-Bondi
framework. This discovery presents the first plausible
explanation for any of the physical CMB anomalies, and raises
the possibility that local large-scale structure could be
responsible for other anomalies as well
RH5.1-CyRPA-Ripr antigen combination vaccine shows little improvement over RH5.1 in a preclinical setting
Background: RH5 is the leading vaccine candidate for the Plasmodium falciparum blood stage and has shown impact on parasite growth in the blood in a human clinical trial. RH5 binds to Ripr and CyRPA at the apical end of the invasive merozoite form, and this complex, designated RCR, is essential for entry into human erythrocytes. RH5 has advanced to human clinical trials, and the impact on parasite growth in the blood was encouraging but modest. This study assessed the potential of a protein-in-adjuvant blood stage malaria vaccine based on a combination of RH5, Ripr and CyRPA to provide improved neutralizing activity against P. falciparum in vitro.
Methods: Mice were immunized with the individual RCR antigens to down select the best performing adjuvant formulation and rats were immunized with the individual RCR antigens to select the correct antigen dose. A second cohort of rats were immunized with single, double and triple antigen combinations to assess immunogenicity and parasite neutralizing activity in growth inhibition assays.
Results: The DPX® platform was identified as the best performing formulation in potentiating P. falciparum inhibitory antibody responses to these antigens. The three antigens derived from RH5, Ripr and CyRPA proteins formulated with DPX induced highly inhibitory parasite neutralising antibodies. Notably, RH5 either as a single antigen or in combination with Ripr and/or CyRPA, induced inhibitory antibodies that outperformed CyRPA, Ripr.
Conclusion: An RCR combination vaccine may not induce substantially improved protective immunity as compared with RH5 as a single immunogen in a clinical setting and leaves the development pathway open for other antigens to be combined with RH5 as a next generation malaria vaccine
Logically Inferred Tuberculosis Transmission (LITT): A Data Integration Algorithm to Rank Potential Source Cases
Understanding tuberculosis (TB) transmission chains can help public health staff target their resources to prevent further transmission, but currently there are few tools to automate this process. We have developed the Logically Inferred Tuberculosis Transmission (LITT) algorithm to systematize the integration and analysis of whole-genome sequencing, clinical, and epidemiological data. Based on the work typically performed by hand during a cluster investigation, LITT identifies and ranks potential source cases for each case in a TB cluster. We evaluated LITT using a diverse dataset of 534 cases in 56 clusters (size range: 2–69 cases), which were investigated locally in three different U.S. jurisdictions. Investigators and LITT agreed on the most likely source case for 145 (80%) of 181 cases. By reviewing discrepancies, we found that many of the remaining differences resulted from errors in the dataset used for the LITT algorithm. In addition, we developed a graphical user interface, user's manual, and training resources to improve LITT accessibility for frontline staff. While LITT cannot replace thorough field investigation, the algorithm can help investigators systematically analyze and interpret complex data over the course of a TB cluster investigation.Code available at:https://github.com/CDCgov/TB_molecular_epidemiology/tree/1.0; https://zenodo.org/badge/latestdoi/166261171
The Epoch of Disk Settling: z~1 to Now
We present evidence from a sample of 544 galaxies from the DEEP2 Survey for
evolution of the internal kinematics of blue galaxies with stellar masses
ranging 8.0 < log M* (M_Sun) < 10.7 over 0.2<z<1.2. DEEP2 provides galaxy
spectra and Hubble imaging from which we measure emission-line kinematics and
galaxy inclinations, respectively. Our large sample allows us to overcome
scatter intrinsic to galaxy properties in order to examine trends in
kinematics. We find that at a fixed stellar mass galaxies systematically
decrease in disordered motions and increase in rotation velocity and potential
well depth with time. Massive galaxies are the most well-ordered at all times
examined, with higher rotation velocities and less disordered motions than less
massive galaxies. We quantify disordered motions with an integrated gas
velocity dispersion corrected for beam smearing (sigma_g). It is unlike the
typical pressure-supported velocity dispersion measured for early type galaxies
and galaxy bulges. Because both seeing and the width of our spectral slits
comprise a significant fraction of the galaxy sizes, sigma_g integrates over
velocity gradients on large scales which can correspond to non-ordered gas
kinematics. We compile measurements of galaxy kinematics from the literature
over 1.2<z<3.8 and do not find any trends with redshift, likely for the most
part because these datasets are biased toward the most highly star-forming
systems. In summary, over the last ~8 billion years since z=1.2, blue galaxies
evolve from disordered to ordered systems as they settle to become the
rotation-dominated disk galaxies observed in the Universe today, with the most
massive galaxies being the most evolved at any time.Comment: submitted to ApJ and responded to referee repor
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