514 research outputs found
Visual Propaganda and Extremism in the Online Environment
Visual images have been a central component of propaganda for as long as propaganda has been produced. But recent developments in communication and information technologies have given terrorist and extremist groups options and abilities they never would have been able to come close to even 5 or 10 years ago. There are terrorist groups who, with very little initial investment, are making videos that are coming so close to the quality of BBC or CNN broadcasts that the difference is meaningless, and with access to the web they have instantaneous access to a global audience. Given the broad social science consensus on the power of visual images relative to that of words, the strategic implications of these groups’ sophistication in the use of images in the online environment is carefully considered in a variety of contexts by the authors in this collection.https://press.armywarcollege.edu/monographs/1942/thumbnail.jp
A robust nanoscale experimental quantification of fracture energy in a bilayer material system
Accurate measurement of interfacial properties is critical any time two materials are bonded—in composites, tooth crowns, or when biomaterials are attached to the human body. Yet, in spite of this importance, reliable methods to measure interfacial properties between dissimilar materials remain elusive. Here we present an experimental approach to quantify the interfacial fracture energy Γ[subscript i] that also provides unique mechanistic insight into the interfacial debonding mechanism at the nanoscale. This approach involves deposition of an additional chromium layer (superlayer) onto a bonded system, where interface debonding is initiated by the residual tensile stress in the superlayer, and where the interface can be separated in a controlled manner and captured in situ. Contrary to earlier methods, our approach allows the entire bonded system to remain in an elastic range during the debonding process, such that Γ[subscript i] can be measured accurately. We validate the method by showing that moisture has a degrading effect on the bonding between epoxy and silica, a technologically important interface. Combining in situ through scanning electron microscope images with molecular simulation, we find that the interfacial debonding mechanism is hierarchical in nature, which is initiated by the detachment of polymer chains, and that the three-dimensional covalent network of the epoxy-based polymer may directly influence water accumulation, leading to the reduction of Γ[subscript i] under presence of moisture. The results may enable us to design more durable concrete composites that could be used to innovate transportation systems, create more durable buildings and bridges, and build resilient infrastructure.National Science Foundation (U.S.) (Grant CMS-0856325
Production of cascade hypernuclei via the (K-,K+) reaction within a quark-meson coupling model
We study the production of bound cascade hypernuclei via the (K-,K+) reaction
on 12C and 28Si targets within a covariant effective Lagrangian model,
employing the cascade bound state spinors derived from the latest quark-meson
coupling model as well as Dirac single particle wave functions. The K+-cascade
production vertex is described by excitation, propagation and decay of Lambda
and Sigma resonance states in the initial collision of a K- meson with a target
proton in the incident channel. The parameters of the resonance vertices are
fixed by describing the available data on total and differential cross sections
for the cascade production in elementary (K-,K+) reaction. We find that both
the elementary and hypernuclear production cross sections are dominated by the
contributions from the Lambda(1520) intermediate resonant state. The 0 degree
differential cross sections for the formation of simple s-state cascade
particle-hole states peak at a beam momentum around 1.0 GeV/c, with a value in
excess of 1 mub.Comment: 17 pages, 8 figures, version accepted for publication in Nucl. Phys.
Trade-Off Between Delineation and Lighting on Freeway Interchanges
DTFH61-85-C-00137The objective was to determine whether, with improved delineation, performance at partially lighted interchanges can approach performance under full lighting, particularly in rain. Two field studies were conducted. The first was to determine whether transient visual adaptation (TVA) influences detection on partially lighted interchanges and could interact with lighting. It was shown that TVA occurs under partial lighting and influences detection up to 600 feet from the last luminaire. The second field study was to determine the effect of lighting, weather, and improved delineation on driver performance. Data were obtained on two exits in dry and wet weather under full lighting with baseline delineation and three improved delineation systems. Partial lighting at one exit was with one luminaire, at the other with three luminaires. Findings support the contention that full lighting is superior to partial lighting in ramp speed-related measures. Analysis of delineation effects on ramp and spot speeds and on speed distributions showed few differences under dry conditions. In rain, effects were stronger but were neither large nor consistent enough to recommend improved delineation over the baseline system. Nonstatistical comparison of the results from two sited provided evidence that three-luminaire partial lighting was superior to single-luminaire. Performance on ramp segments downstream of the last luminaire suggested TVA influenced results
Determination of Driver Needs in Work Zones
DOT-FH-11-9549The objectives of the study were: (a) to determine what information drivers need to travel through work zones safely and efficiently; (b) to determine how this information can best be conveyed to the drivers; and (c) to determine where improvements to the present system of work zone traffic control are needed. The study began with an analysis of driver tasks for eight major work zone types: lane closure, shoulder closure, roadside, lane diversion, crossover, temporary detour, detour to alternate routes, and reduced lane width. From this effort, a set of information content needs was identified for each work zone type. A further analytic effort using the principles of the Positive Guidance Procedure and the concept of Decision Sight Distance, resulted in the identification of recommended information presentation locations for the various types of information. These analytic efforts were combined into information requirements which were then evaluated for applicability by exercising each on a series of actual work zones. The requirements were modified where necessary and were then used as the basis for the development of a procedure for the derivation of work zones signing plans. Another aspect of the project involved the evaluation of individual construction-related signs, in which each device was evaluated with respect to several criteria and problems were identified
PUF60 variants cause a syndrome of ID, short stature, microcephaly, coloboma, craniofacial, cardiac, renal and spinal features.
PUF60 encodes a nucleic acid-binding protein, a component of multimeric complexes regulating RNA splicing and transcription. In 2013, patients with microdeletions of chromosome 8q24.3 including PUF60 were found to have developmental delay, microcephaly, craniofacial, renal and cardiac defects. Very similar phenotypes have been described in six patients with variants in PUF60, suggesting that it underlies the syndrome. We report 12 additional patients with PUF60 variants who were ascertained using exome sequencing: six through the Deciphering Developmental Disorders Study and six through similar projects. Detailed phenotypic analysis of all patients was undertaken. All 12 patients had de novo heterozygous PUF60 variants on exome analysis, each confirmed by Sanger sequencing: four frameshift variants resulting in premature stop codons, three missense variants that clustered within the RNA recognition motif of PUF60 and five essential splice-site (ESS) variant. Analysis of cDNA from a fibroblast cell line derived from one of the patients with an ESS variants revealed aberrant splicing. The consistent feature was developmental delay and most patients had short stature. The phenotypic variability was striking; however, we observed similarities including spinal segmentation anomalies, congenital heart disease, ocular colobomata, hand anomalies and (in two patients) unilateral renal agenesis/horseshoe kidney. Characteristic facial features included micrognathia, a thin upper lip and long philtrum, narrow almond-shaped palpebral fissures, synophrys, flared eyebrows and facial hypertrichosis. Heterozygote loss-of-function variants in PUF60 cause a phenotype comprising growth/developmental delay and craniofacial, cardiac, renal, ocular and spinal anomalies, adding to disorders of human development resulting from aberrant RNA processing/spliceosomal function
Systemic Inhibition of NF-κB Activation Protects from Silicosis
Background: Silicosis is a complex lung disease for which no successful treatment is available and therefore lung transplantation is a potential alternative. Tumor necrosis factor alpha (TNFα) plays a central role in the pathogenesis of silicosis. TNFα signaling is mediated by the transcription factor, Nuclear Factor (NF)-κB, which regulates genes controlling several physiological processes including the innate immune responses, cell death, and inflammation. Therefore, inhibition of NF-κB activation represents a potential therapeutic strategy for silicosis. Methods/Findings: In the present work we evaluated the lung transplant database (May 1986-July 2007) at the University of Pittsburgh to study the efficacy of lung transplantation in patients with silicosis (n = 11). We contrasted the overall survival and rate of graft rejection in these patients to that of patients with idiopathic pulmonary fibrosis (IPF, n = 79) that was selected as a control group because survival benefit of lung transplantation has been identified for these patients. At the time of lung transplantation, we found the lungs of silica-exposed subjects to contain multiple foci of inflammatory cells and silicotic nodules with proximal TNFα expressing macrophage and NF-κB activation in epithelial cells. Patients with silicosis had poor survival (median survival 2.4 yr; confidence interval (CI): 0.16-7.88 yr) compared to IPF patients (5.3 yr; CI: 2.8-15 yr; p = 0.07), and experienced early rejection of their lung grafts (0.9 yr; CI: 0.22-0.9 yr) following lung transplantation (2.4 yr; CI:1.5-3.6 yr; p<0.05). Using a mouse experimental model in which the endotracheal instillation of silica reproduces the silica-induced lung injury observed in humans we found that systemic inhibition of NF-κB activation with a pharmacologic inhibitor (BAY 11-7085) of IκBα phosphorylation decreased silica-induced inflammation and collagen deposition. In contrast, transgenic mice expressing a dominant negative IκBα mutant protein under the control of epithelial cell specific promoters demonstrate enhanced apoptosis and collagen deposition in their lungs in response to silica. Conclusions: Although limited by its size, our data support that patients with silicosis appear to have poor outcome following lung transplantation. Experimental data indicate that while the systemic inhibition of NF-κB protects from silica-induced lung injury, epithelial cell specific NF-κB inhibition appears to aggravate the outcome of experimental silicosis. © 2009 Di Giuseppe et al
Phenomenological model for the Kbar N --> K Xi reaction
A phenomenological model for the Kbar N --> K Xi reaction is suggested. The
model includes s and u channel exchanges by Lambda, Sigma, Sigma(1385), and
Lambda(1520) and s channel exchanges by above-threshold hyperonic resonances.
Explicit expression for the propagator for a particle with spin 7/2 is
presented. High-mass and high-spin resonances play a significant role in the
process. We deal with the whole set of existing experimental data on the cross
sections and polarizations in the energy range from the threshold to 2.8 GeV in
the center-of-mass system and reach a good agreement with experiments.
Applications of the model to other elementary reactions of Xi production and to
Xi hypernuclear spectroscopy are briefly discussed.Comment: Published version; minor change
- …