6,261 research outputs found
Finding by Counting: A Probabilistic Packet Count Model for Indoor Localization in BLE Environments
We propose a probabilistic packet reception model for Bluetooth Low Energy
(BLE) packets in indoor spaces and we validate the model by using it for indoor
localization. We expect indoor localization to play an important role in indoor
public spaces in the future. We model the probability of reception of a packet
as a generalized quadratic function of distance, beacon power and advertising
frequency. Then, we use a Bayesian formulation to determine the coefficients of
the packet loss model using empirical observations from our testbed. We develop
a new sequential Monte-Carlo algorithm that uses our packet count model. The
algorithm is general enough to accommodate different spatial configurations. We
have good indoor localization experiments: our approach has an average error of
~1.2m, 53% lower than the baseline range-free Monte-Carlo localization
algorithm.Comment: 8 pages, 6 figures, to be published in WiNTECH 201
Reimagining the dissemination of engineering education practices through a global learning partnership
Attitudes and Beliefs of African-Americans Toward Genetics, Genetic Testing, and Sickle Cell Disease Education and Awareness
Research among African-Americans indicates this population perceives sickle cell (SCD) to be a serious disease and sickle cell trait (SCT) screening an important intervention. However, studies have consistently demonstrated a lower than desired uptake of SCD education, inadequate knowledge regarding personal and family trait status, and a low perceived susceptibility of giving birth to a child with the disease. We examined general attitudes and beliefs regarding genetics and genetic testing including prenatal testing and newborn screening; we used this information as the foundation to more specifically assess attitudes and beliefs regarding SCD and perceived barriers to SCD education and awareness. Thirty-five African-American adult men and women participated in one of four focus groups. Thematic analysis identified that both prenatal testing and newborn screening are acceptable forms of genetic testing. Based largely on their personal experiences, participants possessed an understanding of the natural progression of SCD but had a limited understanding of the inheritance and probable risk of giving birth to a child with the disease. Barriers to education and greater awareness of SCD were classified as personal, familial, and societal. Community based interventions focused on sharing the stories of individuals with first-hand experiences with SCD should be considered
Plasma Membrane Profiling Reveals Upregulation of ABCA1 by Infected Macrophages Leading to Restriction of Mycobacterial Growth.
The plasma membrane represents a critical interface between the internal and extracellular environments, and harbors multiple proteins key receptors and transporters that play important roles in restriction of intracellular infection. We applied plasma membrane profiling, a technique that combines quantitative mass spectrometry with selective cell surface aminooxy-biotinylation, to Bacille Calmette-Guérin (BCG)-infected THP-1 macrophages. We quantified 559 PM proteins in BCG-infected THP-1 cells. One significantly upregulated cell-surface protein was the cholesterol transporter ABCA1. We showed that ABCA1 was upregulated on the macrophage cell-surface following infection with pathogenic mycobacteria and knockdown of ABCA1 resulted in increased mycobacterial survival within macrophages, suggesting that it may be a novel mycobacterial host-restriction factor.Medical Research Council (Clinician Scientist Fellowship), Tsinghua University, Wellcome Trust (Senior Fellowship (Grant ID: 108070/Z/15/Z)), National Institute for Health Research (Academic Clinical Fellowship), China Scholarship CouncilThis is the final version of the article. It first appeared from Frontiers via http://dx.doi.org/10.3389/fmicb.2016.0108
An Uncommon Undergraduate Experience: Conducting Research and Fieldwork in Ecological Restoration
The Ecological Restoration Institute (ERI) at Northern Arizona University offers a formal program to encourage undergraduate students to integrate research and educational activities. In the past three years, 55 undergraduates representing 18 majors have been financially supported to participate in ecological research and practical work experience. Students selected and awarded assistantships work as year-round researchers in campus laboratories and as summer field crew assistants at research sites across the Colorado Plateau
The Milky Way Tomography with SDSS: III. Stellar Kinematics
We study Milky Way kinematics using a sample of 18.8 million main-sequence
stars with r<20 and proper-motion measurements derived from SDSS and POSS
astrometry, including ~170,000 stars with radial-velocity measurements from the
SDSS spectroscopic survey. Distances to stars are determined using a
photometric parallax relation, covering a distance range from ~100 pc to 10 kpc
over a quarter of the sky at high Galactic latitudes (|b|>20 degrees). We find
that in the region defined by 1 kpc <Z< 5 kpc and 3 kpc <R< 13 kpc, the
rotational velocity for disk stars smoothly decreases, and all three components
of the velocity dispersion increase, with distance from the Galactic plane. In
contrast, the velocity ellipsoid for halo stars is aligned with a spherical
coordinate system and appears to be spatially invariant within the probed
volume. The velocity distribution of nearby ( kpc) K/M stars is complex,
and cannot be described by a standard Schwarzschild ellipsoid. For stars in a
distance-limited subsample of stars (<100 pc), we detect a multimodal velocity
distribution consistent with that seen by HIPPARCOS. This strong
non-Gaussianity significantly affects the measurements of the velocity
ellipsoid tilt and vertex deviation when using the Schwarzschild approximation.
We develop and test a simple descriptive model for the overall kinematic
behavior that captures these features over most of the probed volume, and can
be used to search for substructure in kinematic and metallicity space. We use
this model to predict further improvements in kinematic mapping of the Galaxy
expected from Gaia and LSST.Comment: 90 pages, 26 figures, submitted to Ap
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