22,880 research outputs found
Bright gamma-ray Galactic Center excess and dark dwarfs: Strong tension for dark matter annihilation despite Milky Way halo profile
We incorporate Milky Way dark matter halo profile uncertainties, as well as
an accounting of diffuse gamma-ray emission uncertainties in dark matter
annihilation models for the Galactic Center Extended gamma-ray excess (GCE)
detected by the Fermi Gamma Ray Space Telescope. The range of particle
annihilation rate and masses expand when including these unknowns. However, two
of the most precise empirical determinations of the Milky Way halo's local
density and density profile leave the signal region to be in considerable
tension with dark matter annihilation searches from combined dwarf galaxy
analyses for single-channel dark matter annihilation models. The GCE and dwarf
tension can be alleviated if: one, the halo is very highly concentrated or
strongly contracted; two, the dark matter annihilation signal differentiates
between dwarfs and the GC; or, three, local stellar density measures are found
to be significantly lower, like that from recent stellar counts, increasing the
local dark matter density.Comment: 9 pages, 3 figures; v3 & v4: match version to appear in PRD; analysis
code available at https://github.com/rekeeley/GCE_error
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Face-to-face or distance training? Two different approaches to motivate SMEs to learn - an update
In the past, too many government-sponsored initiatives have presented learning resources that have been wasted because the target small business audience has failed to make use of them. This paper explores the issue of offering learning materials to small and medium-sized enterprises (SMEs) in a manner that recognizes their working environment, mode of operation and preferred learning methods. It then outlines methods currently being tested in the UK and Ireland, and indicates preliminary findings. The two methodologies are different in that the UK (LSSB - Learning Support for Small Businesses) programme is aimed at distance learning in primarily small businesses, whilst the Irish (University of Limerick and Limerick City Enterprise Board) programme is aimed at face-to-face learning primarily in micro-enterprises. Preliminary findings are presented
Validation of Satellite Rainfall Products for Western Uganda.
Central equatorial Africa is deficient in long-term, ground-based measurements of rainfall; therefore, the aim of this study is to assess the accuracy of three high-resolution, satellite-based rainfall products in western Uganda for the 2001–10 period. The three products are African Rainfall Climatology, version 2 (ARC2); African Rainfall Estimation Algorithm, version 2 (RFE2); and 3B42 from the Tropical Rainfall Measuring Mission, version 7 (i.e., 3B42v7). Daily rainfall totals from six gauges were used to assess the accuracy of satellite-based rainfall estimates of rainfall days, daily rainfall totals, 10-day rainfall totals, monthly rainfall totals, and seasonal rainfall totals. The northern stations had a mean annual rainfall total of 1390 mm, while the southern stations had a mean annual rainfall total of 900 mm. 3B42v7 was the only product that did not underestimate boreal-summer rainfall at the northern stations, which had ~3 times as much rainfall during boreal summer than did the southern stations. The three products tended to overestimate rainfall days at all stations and were borderline satisfactory at identifying rainfall days at the northern stations; the products did not perform satisfactorily at the southern stations. At the northern stations, 3B42v7 performed satisfactorily at estimating monthly and seasonal rainfall totals, ARC2 was only satisfactory at estimating seasonal rainfall totals, and RFE2 did not perform satisfactorily at any time step. The satellite products performed worst at the two stations located in rain shadows, and 3B42v7 had substantial overestimates at those stations
What the Milky Way's Dwarfs tell us about the Galactic Center extended excess
The Milky Way's Galactic Center harbors a gamma-ray excess that is a
candidate signal of annihilating dark matter. Dwarf galaxies remain
predominantly dark in their expected commensurate emission. In this work we
quantify the degree of consistency between these two observations through a
joint likelihood analysis. In doing so we incorporate Milky Way dark matter
halo profile uncertainties, as well as an accounting of diffuse gamma-ray
emission uncertainties in dark matter annihilation models for the Galactic
Center Extended gamma-ray excess (GCE) detected by the Fermi Gamma-Ray Space
Telescope. The preferred range of annihilation rates and masses expands when
including these unknowns. Even so, using two recent determinations of the Milky
Way halo's local density leave the GCE preferred region of single-channel dark
matter annihilation models to be in strong tension with annihilation searches
in combined dwarf galaxy analyses. A third, higher Milky Way density
determination, alleviates this tension. Our joint likelihood analysis allows us
to quantify this inconsistency. We provide a set of tools for testing dark
matter annihilation models' consistency within this combined dataset. As an
example, we test a representative inverse Compton sourced self-interacting dark
matter model, which is consistent with both the GCE and dwarfs.Comment: v2, 12 pages, 4 figures, tools online at:
https://github.com/rekeeley/GCE_error
A Catalog of MIPSGAL Disk and Ring Sources
We present a catalog of 416 extended, resolved, disk- and ring-like objects
as detected in the MIPSGAL 24 micron survey of the Galactic plane. This catalog
is the result of a search in the MIPSGAL image data for generally circularly
symmetric, extended "bubbles" without prior knowledge or expectation of their
physical nature. Most of the objects have no extended counterpart at 8 or 70
micron, with less than 20% detections at each wavelength. For the 54 objects
with central point sources, the sources are nearly always seen in all IRAC
bands. About 70 objects (16%) have been previously identified, with another 35
listed as IRAS sources. Among the identified objects, those with central
sources are mostly listed as emission-line stars, but with other source types
including supernova remnants, luminous blue variables, and planetary nebulae.
The 57 identified objects (of 362) without central sources are nearly all PNe
(~90%).which suggests that a large fraction of the 300+ unidentified objects in
this category are also PNe. These identifications suggest that this is
primarily a catalog of evolved stars. Also included in the catalog are two
filamentary objects that are almost certainly SNRs, and ten unusual compact
extended objects discovered in the search. Two of these show remarkable spiral
structure at both 8 and 24 micron. These are likely background galaxies
previously hidden by the intervening Galactic plane
Telecommunications and data acquisition support for the Pioneer Venus Project: Pioneers 12 and 13, prelaunch through March 1984
The support provided by the Telecommunications and Data Acquisition organization of the Jet Propulsion Laboratory (JPL) to the Pioneer Venus missions is described. The missions were the responsibility of the Ames Research Center (ARC). The Pioneer 13 mission and its spacecraft design presented one of the greatest challenges to the Deep Space Network (DSN) in the implementation and operation of new capabilities. The four probes that were to enter the atmosphere of Venus were turned on shortly before arrival at Venus, and the DSN had to acquire each of these probes in order to recover the telemetry being transmitted. Furthermore, a science experiment involving these probes descending through the atmosphere required a completed new data type to be generated at the ground stations. This new data type is known as the differential very long baseline interferometry. Discussions between ARC and JPL of the implementation requirements involved trade-offs in spacecraft design and led to a very successful return of science data. Specific implementation and operational techniques are discussed, not only for the prime mission, but also for the extended support to the Pioneer 12 spacecraft (in orbit around Venus) with its science instruments including that for radar observations of the planet
Exploring Challenges in Conducting E-Mental Health Research Among Asian American Women
In this discussion paper, we explore the challenges of conducting e-mental health intervention research among Asian American women and propose a model for addressing these barriers. Based on an extensive literature review, we identify two main types of barriers to conducting e-mental health intervention research among Asian American women: recruitment barriers and adherence barriers. Recruitment barriers are further subcategorized into those related to (1) stigmatized cultural beliefs about mental illness and mental health services; (2) lack of awareness about mental health services; and (3) language barrier. As to adherence barriers, the two identified subtypes concern (1) acuity and severity of mental health condition; and (2) lack of time. In order to enhance recruitment and adherence in e-mental health intervention research among the studied population, we formulate the following three main research strategies, namely: (1) considering the cultural and social contexts of Asian American women in the development of e-mental health interventions; (2) determining appropriate program length; and (3) conducting feasibility studies to test e-mental health interventions. We suggest that nurse researchers integrate our proposed model in conducting e-mental health interventions among Asian American women. Our proposed model also implies that nurses play an important role in encouraging Asian American women’s acceptance of and adherence to e-mental health interventions. In order to overcome the obstacles to conducting e-mental health research among Asian American women, we recommend that nurses familiarize themselves with credible, relevant, and evidence-based e-mental health resources and integrate online mental health services and information within their nursing practice
Cost-effectiveness of the Manchester approach to identifying Lynch syndrome in women with endometrial cancer
This is the final version. Available on open access from MDPI via the DOI in this recordLynch syndrome (LS) is a hereditary cancer syndrome responsible for 3% of all
endometrial cancer and 5% in those aged under 70 years. It is unclear whether universal testing for
LS in endometrial cancer patients would be cost-effective. The Manchester approach to identifying
LS in endometrial cancer patients uses immunohistochemistry (IHC) to detect mismatch repair
(MMR) deficiency, incorporates testing for MLH1 promoter hypermethylation, and genetic testing
for pathogenic MMR variants. We aimed to assess the cost-effectiveness of the Manchester approach
based on primary research data from clinical practice in Manchester. The PETALS study informed
estimates of diagnostic performances for a number of different strategies. A recent microcosting
study was adapted and used to estimate diagnostic costs. A Markov model was used to predict
long-term costs and health outcomes (measured in quality-adjusted life years, QALYs) for
individuals and their relatives. Bootstrapping and probabilistic sensitivity analysis were used to
estimate the uncertainty in cost-effectiveness. The Manchester approach dominated other reflex
testing strategies when considering diagnostic costs and Lynch syndrome cases identified. When
considering long-term costs and QALYs the Manchester approach was the optimal strategy, costing
£5459 per QALY gained (compared to thresholds of £20,000 to £30,000 per QALY commonly used
in the NHS). Cost-effectiveness is not an argument for restricting testing to younger patients or those
with a strong family history. Universal testing for Lynch syndrome in endometrial cancer patients
is expected to be cost-effective in the UK NHS, and the Manchester approach is expected to be the
optimal testing strategy.Medical Research Council (MRC)National Institute for Health Research (NIHR
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