724 research outputs found
A Panel Data Regression Model for Defense Merger and Acquisition Activity
Excerpt: This paper examines the relationship between a prime contractor\u27s financial health and its mergers and acquisitions (M&A) spending in the defense industry. It aims to provide models that give the United States Department of Defense (DoD) indications of future M&A activity, informing decision-makers and contributing to ensuring competitive markets that benefit the consumer.
The results show a significant relationship between efficiency and M&A spending, indicating that companies with lower efficiency tend to spend more on M&As. However, there was no significant relationship between M&A spending and a company\u27s profitability or solvency. These results were consistent with previous research and the study\u27s hypotheses for profitability and solvency. However, the effect of liquidity was the opposite of the expected result, possibly due to the defense industry\u27s different view on liquidity compared to previous research
Identification of Preferred DNA-Binding Sites for the Thermus thermophilus Transcriptional Regulator SbtR by the Combinatorial Approach REPSA
One of the first steps towards elucidating the biological function of a putative transcriptional regulator is to ascertain its preferred DNA-binding sequences. This may be rapidly and effectively achieved through the application of a combinatorial approach, one involving very large numbers of randomized oligonucleotides and reiterative selection and amplification steps to enrich for high-affinity nucleic acid-binding sequences. Previously, we had developed the novel combinatorial approach Restriction Endonuclease Protection, Selection and Amplification (REPSA), which relies not on the physical separation of ligand-nucleic acid complexes but instead selects on the basis of ligand-dependent inhibition of enzymatic template inactivation, specifically cleavage by type IIS restriction endonucleases. Thus, no prior knowledge of the ligand is required for REPSA, making it more amenable for discovery purposes. Here we describe using REPSA, massively parallel sequencing, and bioinformatics to identify the preferred DNA-binding sites for the transcriptional regulator SbtR, encoded by the TTHA0167 gene from the model extreme thermophile Thermus thermophilus HB8. From the resulting position weight matrix, we can identify multiple operons potentially regulated by SbtR and postulate a biological role for this protein in regulating extracellular transport processes. Our study provides a proof-of-concept for the application of REPSA for the identification of preferred DNA-binding sites for orphan transcriptional regulators and a first step towards determining their possible biological roles
Plasma-Based Detector of Outer-Space Dust Particles
A report presents a concept for an instrument to be flown in outer space, where it would detect dust particles - especially those associated with comets. The instrument would include a flat plate that would intercept the dust particles. The anticipated spacecraft/dust-particle relative speeds are so high that the impingement of a dust particle on the plate would generate a plasma cloud. Simple electric dipole sensors located equidistantly along the circumference of the plate would detect the dust particle indirectly by detecting the plasma cloud. The location of the dust hit could be estimated from the timing of the detection pulses of the different dipoles. The mass and composition of the dust particle could be estimated from the shapes and durations of the pulses from the dipoles. In comparison with other instruments for detecting hypervelocity dust particles, the proposed instrument offers advantages of robustness, large collection area, and simplicity
The Path to God is Through the Heart: Metaphoric Self-location as a Predictor of Religiosity
Metaphors linking the heart to warm intuition and the head to cold rationality may capture important differences between people because some locate the self in the heart and others locate the self in the head. Five studies (total N = 2575) link these individual differences to religious beliefs. Study 1 found that religious beliefs were stronger among heart-locators than head-locators. Studies 2 and 3 replicated this relationship in more diverse samples. Studies 4 and 5 focused on questions of mediation. Heart-locators believed in God to a greater extent partly because of empathy-related processes (Study 4) and partly because they tended to think in less analytic terms (Study 5). These studies extend our knowledge of how metaphors interact with personality processes
Tailored for Real-World: A Whole Slide Image Classification System Validated on Uncurated Multi-Site Data Emulating the Prospective Pathology Workload.
Standard of care diagnostic procedure for suspected skin cancer is microscopic examination of hematoxylin & eosin stained tissue by a pathologist. Areas of high inter-pathologist discordance and rising biopsy rates necessitate higher efficiency and diagnostic reproducibility. We present and validate a deep learning system which classifies digitized dermatopathology slides into 4 categories. The system is developed using 5,070 images from a single lab, and tested on an uncurated set of 13,537 images from 3 test labs, using whole slide scanners manufactured by 3 different vendors. The system\u27s use of deep-learning-based confidence scoring as a criterion to consider the result as accurate yields an accuracy of up to 98%, and makes it adoptable in a real-world setting. Without confidence scoring, the system achieved an accuracy of 78%. We anticipate that our deep learning system will serve as a foundation enabling faster diagnosis of skin cancer, identification of cases for specialist review, and targeted diagnostic classifications
Recommended from our members
Downhole induction heater and coupling system for oil and gas wells
Described herein are methods and system that use electromagnetic heating to heat wellbores and the fluids therein. The heating is achieved by placing one or more permanent magnets in the wellbore and moving a metallic component and/or the one or more permanent magnets relative to each other. This generates eddy currents in the metallic component, which heat the metallic component. This heat is transferred to the fluids in the wellbore from the metallic component by convection. In some embodiments, permanent magnets are installed in the tubing to induce eddy current heating in a well by converting the linear motion of a sucker rod to rotary motion of a conducting tube using a lead or ball screw. The heater may directly integrate with existing pump jack equipment with little or no additional infrastructure required.Board of Regents, University of Texas Syste
Landscape Features Affecting Northern Bobwhite Predator-Specific Nest Failures in Southeastern USA
Nest predation is a critical component in avian productivity and typically is the leading cause of nest failure for most birds. Several landscape features are thought to drive the behavioral interaction between northern bobwhite (Colinus virginianus; e.g., nest placement) and their predators (e.g., search methods for food acquisition). In order to understand habitat characteristics influencing predation, we studied bobwhite nests using 24-hour near-infrared video cameras. We monitored 675 bobwhite nests with cameras on 3 properties in northern Florida and southern Georgia, USA, during 2000–2006. To test the association between nest failures and specific failure causes with landscape structure, we calculated a suite of landscape metrics and examined these at 3 spatial scales (3.1 ha, 19.6 ha, and 50.3 ha). We found increased probability of nest success with greater proportions of, and proximity to, fallow and annually disked fields at larger scales (50.3 ha), but we found no landscape metrics to be important predictors of bobwhite nest failures at small scales (\u3c20 \u3eha). Fallow and disked fields may provide alternative prey items (e.g., rodents) important in buffering nest predation. Relative to meso-mammal predation, we observed increases in proportion of the landscape in field to be related to lower incidental nest failures at the smallest scale (3.1 ha). Nests closer to feed lines were more likely depredated by meso-mammals than ants at the 2 larger spatial scales. Interestingly, the fate of a nest was independent of the fate of neighboring nests, suggesting bobwhite nest predation may be primarily incidental
Topology of structure in the Sloan Digital Sky Survey: model testing
We measure the three-dimensional topology of large-scale structure in the
Sloan Digital Sky Survey (SDSS). This allows the genus statistic to be measured
with unprecedented statistical accuracy. The sample size is now sufficiently
large to allow the topology to be an important tool for testing galaxy
formation models. For comparison, we make mock SDSS samples using several
state-of-the-art N-body simulations: the Millennium run of Springel et al.
(2005)(10 billion particles), Kim & Park (2006) CDM models (1.1 billion
particles), and Cen & Ostriker (2006) hydrodynamic code models (8.6 billion
cell hydro mesh). Each of these simulations uses a different method for
modeling galaxy formation. The SDSS data show a genus curve that is broadly
characteristic of that produced by Gaussian random phase initial conditions.
Thus the data strongly support the standard model of inflation where Gaussian
random phase initial conditions are produced by random quantum fluctuations in
the early universe. But on top of this general shape there are measurable
differences produced by non-linear gravitational effects (cf. Matsubara 1994),
and biasing connected with galaxy formation. The N-body simulations have been
tuned to reproduce the power spectrum and multiplicity function but not
topology, so topology is an acid test for these models. The data show a
``meatball'' shift (only partly due to the Sloan Great Wall of Galaxies; this
shift also appears in a sub-sample not containing the Wall) which differs at
the 2.5\sigma level from the results of the Millennium run and the Kim & Park
dark halo models, even including the effects of cosmic variance.Comment: 13 Apj pages, 7 figures High-resolution stereo graphic available at
http://www.astro.princeton.edu/~dclayh/stereo50.ep
Persistence of apoptotic cells without autoimmune disease or inflammation in CD14−/− mice
Interaction of macrophages with apoptotic cells involves multiple steps including recognition, tethering, phagocytosis, and anti-inflammatory macrophage responses. Defective apoptotic cell clearance is associated with pathogenesis of autoimmune disease. CD14 is a surface receptor that functions in vitro in the removal of apoptotic cells by human and murine macrophages, but its mechanism of action has not been defined. Here, we demonstrate that CD14 functions as a macrophage tethering receptor for apoptotic cells. Significantly, CD14−/− macrophages in vivo are defective in clearing apoptotic cells in multiple tissues, suggesting a broad role for CD14 in the clearance process. However, the resultant persistence of apoptotic cells does not lead to inflammation or increased autoantibody production, most likely because, as we show, CD14−/− macrophages retain the ability to generate anti-inflammatory signals in response to apoptotic cells. We conclude that CD14 plays a broad tethering role in apoptotic cell clearance in vivo and that apoptotic cells can persist in the absence of proinflammatory consequences
- …