Brain activity linked to the filtering of visual information under uncertain conditions

Abstract onl

Liveness-Driven Random Program Generation

Randomly generated programs are popular for testing compilers and program analysis tools, with hundreds of bugs in real-world C compilers found by random testing. However, existing random program generators may generate large amounts of dead code (computations whose result is never used). This leaves relatively little code to exercise a target compiler's more complex optimizations. To address this shortcoming, we introduce liveness-driven random program generation. In this approach the random program is constructed bottom-up, guided by a simultaneous structural data-flow analysis to ensure that the generator never generates dead code. The algorithm is implemented as a plugin for the Frama-C framework. We evaluate it in comparison to Csmith, the standard random C program generator. Our tool generates programs that compile to more machine code with a more complex instruction mix.Comment: Pre-proceedings paper presented at the 27th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur, Belgium, 10-12 October 2017 (arXiv:1708.07854

Differences in the evolution of the ischemic penumbra in stroke-prone spontaneously hypertensive and Wistar-Kyoto rats

<p><b>Background and Purpose:</b> Stroke-prone spontaneously hypertensive rats (SHRSP) are a highly pertinent stroke model with increased sensitivity to focal ischemia compared with the normotensive reference strain (Wistar-Kyoto rats; WKY). Study aims were to investigate temporal changes in the ischemic penumbra in SHRSP compared with WKY.</p> <p><b>Methods:</b> Permanent middle cerebral artery occlusion was induced with an intraluminal filament. Diffusion- (DWI) and perfusion- (PWI) weighted magnetic resonance imaging was performed from 1 to 6 hours after stroke, with the PWI-DWI mismatch used to define the penumbra and thresholded apparent diffusion coefficient (ADC) maps used to define ischemic damage.</p> <p><b>Results:</b> There was significantly more ischemic damage in SHRSP than in WKY from 1 to 6 hours after stroke. The perfusion deficit remained unchanged in WKY (39.9±6 mm<sup>2</sup> at 1 hour, 39.6±5.3 mm<sup>2</sup> at 6 hours) but surprisingly increased in SHRSP (43.9±9.2 mm<sup>2</sup> at 1 hour, 48.5±7.4 mm<sup>2</sup> at 6 hours; P=0.01). One hour after stroke, SHRSP had a significantly smaller penumbra (3.4±5.8 mm<sup>2</sup>) than did WKY (9.7±3.8, P=0.03). In WKY, 56% of the 1-hour penumbra area was incorporated into the ADC lesion by 6 hours, whereas in SHRSP, the small penumbra remained static owing to the temporal increase in both ADC lesion size and perfusion deficit.</p> <p><b>Conclusions:</b> First, SHRSP have significantly more ischemic damage and a smaller penumbra than do WKY within 1 hour of stroke; second, the penumbra is recruited into the ADC abnormality over time in both strains; and third, the expanding perfusion deficit in SHRSP predicts more tissue at risk of infarction. These results have important implications for management of stroke patients with preexisting hypertension and suggest ischemic damage could progress at a faster rate and over a longer time frame in the presence of hypertension.</p&gt

Bovine Viral Diarrhea Virus Multiorgan Infection in Two White-Tailed Deer in Southeastern South Dakota

The susceptibility of wild ruminants, especially cervids, to bovine viral diarrhea virus (BVDV) has remained an enigma. Two white-tailed deer (Odocoileus virginianus) were submitted to the Animal Disease Research and Diagnostic Laboratory (ADRDL) in the fall of 2003 by the South Dakota Game Fish and Parks for chronic wasting disease (CWD) testing. Both animals were CWD negative. The animals were necropsied and histopathology, viral antigen detection, and virus isolation were performed. A noncytopathic (NCP) BVDV was isolated from the lungs and several other tissues of both animals. Formalin-fixed ear notches from both animals were positive for BVDV antigen by immunohistochemistry. The BVDV isolates were typed with the use of polymerase chain reaction in 59 untranslated region (UTR) and one isolate was typed a Type 2a and the other a Type 1b. Future field surveys to determine the incidence of BVDV along with experimental studies to determine if whitetailed deer fawns can be persistently infected with BVDV are neede

Evaluating the Environmental Performance of the U.S. Next Generation Air Transportation System

The environmental impacts of several possible U.S. Next Generation Air Transportation scenarios have been quantitatively evaluated for noise, air-quality, fuel-efficiency, and CO2 impacts. Three principal findings have emerged. (1) 2025 traffic levels about 30% higher than 2006 are obtained by increasing traffic according to FAA projections while also limiting traffic at each airport using reasonable ratios of demand to capacity. NextGen operational capabilities alone enable attainment of an additional 10-15% more flights beyond that 2025 baseline level with negligible additional noise, air-quality, and fuel-efficiency impacts. (2) The addition of advanced engine and airframe technologies provides substantial additional reductions in noise and air-quality impacts, and further improves fuel efficiency. 2025 environmental goals based on projected system-wide improvement rates of about 1% per year for noise and fuel-efficiency (an air-quality goal is not yet formulated) are achieved using this new vehicle technology. (3) Overall air-transport "product", as measured by total flown distance or total payload distance, increases by about 50% relative to 2006, but total fuel consumption and CO2 production increase by only about 40% using NextGen operational capabilities. With the addition of advanced engine/airframe technologies, the increase in total fuel consumption and CO2 production can be reduced to about 30%

Hurricane impacts on the Caribbean coastal/marine environment : using scientific assessment to plan for the future

The passage of Hurricane Hugo through the eastern Caribbean provided a unique opportunity for multidisciplinary study of (1) the effects of severe storms on tropical coastal and marine ecosystems, and (2) the physical and biological responses of those ecosystems to intense storm-induced changes. In addition to its direct value as basic science, this study can be used to facilitate development of improved coastal and marine resource management capabilities.Funding was provided by the Andrew W. Mellon Foundation to the Coastal Research Center of the Woods Hole Oceanographic Institution (WHOI) and the NOAA National Sea Grant College Program Offce, Department of Commerce, under Grant No. NA86-AA-D-90

An expanded M bh -σ diagram, and a new calibration of active galactic nuclei masses

ABSTRACT We present an updated and improved M bh -σ diagram containing 64 galaxies for which M bh measurements (not just upper limits) are available. Because of new and increased black hole masses at the high-mass end, and a better representation of barred galaxies at the low-mass end, the 'classical' (all morphological type) M bh -σ relation for predicting black hole masses is log (M bh /M ) = (8.13 ± 0.05) + (5.13 ± 0.34)log [σ /200 km s Using updated virial products and velocity dispersions from 28 active galactic nuclei, we determine that the optimal scaling factor f -which brings their virial products in line with the 64 directly measured black hole masses -is 2.8 +0.7 −0.5 . This is roughly half the value reported by Onken et al. and Woo et al., and consequently halves the mass estimates of most high-redshift quasars. Given that barred galaxies are, on average, located ∼0.5 dex below the 'barless' and 'elliptical-only' M bh -σ relations, we have explored the results after separating the samples into barred and non-barred galaxies, and we have also developed a preliminary corrective term to the velocity dispersion based on bar dynamics. In addition, given the recently recognized coexistence of massive black holes and nuclear star clusters, we present the first ever (M bh + M nc )-σ diagram and begin to explore how galaxies shift from their former location in the M bh -σ diagram

Hurricanes and Homeowner Decision-Making

The researchers conducted surveys between 2001 and 2002 that examined homeowner decisions concerning wind damage to homes from hurricanes. They collected information about current mitigation practices, expectation of damage, and willingness to pay for future mitigation improvements. Their key findings were that income, size of the deductible, and expected damages from a category three hurricane—but not category four or five hurricanes—were the main determining factors for people that do mitigation. Homeowners generally dismissed low probability events. They found that homeowner willingness to pay for mitigation devices is negative and requires subsidy in excess of $14,000. Willingness to pay is greater if insurance is not available. They concluded that most homeowners are not willing to purchase excessive mitigation devices