Local error estimates for adaptive simulation of the Reaction-Diffusion Master Equation via operator splitting

The efficiency of exact simulation methods for the reaction-diffusion master equation (RDME) is severely limited by the large number of diffusion events if the mesh is fine or if diffusion constants are large. Furthermore, inherent properties of exact kinetic-Monte Carlo simulation methods limit the efficiency of parallel implementations. Several approximate and hybrid methods have appeared that enable more efficient simulation of the RDME. A common feature to most of them is that they rely on splitting the system into its reaction and diffusion parts and updating them sequentially over a discrete timestep. This use of operator splitting enables more efficient simulation but it comes at the price of a temporal discretization error that depends on the size of the timestep. So far, existing methods have not attempted to estimate or control this error in a systematic manner. This makes the solvers hard to use for practitioners since they must guess an appropriate timestep. It also makes the solvers potentially less efficient than if the timesteps are adapted to control the error. Here, we derive estimates of the local error and propose a strategy to adaptively select the timestep when the RDME is simulated via a first order operator splitting. While the strategy is general and applicable to a wide range of approximate and hybrid methods, we exemplify it here by extending a previously published approximate method, the Diffusive Finite-State Projection (DFSP) method, to incorporate temporal adaptivity

Unmasking Hidden Commercials in Broadcasting: Origins of the Sponsorship Identification Regulations, 1927-1963

This Article by Richard Kielbowicz and Linda Lawson is an exploration of the origins of sponsorship identification regulations as they pertained to early radio and television programming. Beginning with the statutory sponsorship identification requirement enacted in 1927, the Authors trace the development of sponsorship identification rules in the communications industry. By arguing that such rules express a basic goal of American communication law and policy, Kielbowicz and Lawson analyze trends and developments in sponsorship regulation that did not materialize in the 1930s and 1940s because of the nature of early broadcast sponsorship. The Authors then assert that those same early rules proved unexpectedly useful in dealing with a 1940s\u27 controversy over covert political promotions. Next, the piece reveals that the FCC failed to apply the rule to broadcast practices that had become commonplace in the 1950s, such as quiz show rigging, payola and plugola. The Article then analyzes the 1960 amendments to the Communications Act and examines the resulting rules, which unsuccessfully proposed extending the rules into broadcasters\u27 financial interests. Finally, the Authors conclude by analyzing the dynamics that produced the 1963 regulations

Investigation of Individual Instruction and its Application to the Operation of Audio-Visual Equipment

Clothing, Textiles, and Merchandisin

Current practices in cancer spatial data analysis: a call for guidance

There has long been a recognition that place matters in health, from recognition of clusters of yellow fever and cholera in the 1800s to modern day analyses of regional and neighborhood effects on cancer patterns. Here we provide a summary of discussions about current practices in the spatial analysis of georeferenced cancer data by a panel of experts recently convened at the National Cancer Institute

Effect of Hyperbaric Oxygen Therapy on whole blood cyanide concentrations in carbon monoxide intoxicated patients from fire accidents

<p>Abstract</p> <p>Background</p> <p>Hydrogen cyanide (HCN) and carbon monoxide (CO) may be important components of smoke from fire accidents. Accordingly, patients admitted to hospital from fire accidents may have been exposed to both HCN and CO. Cyanide (CN) intoxication results in cytotoxic hypoxia leading to organ dysfunction and possibly death. While several reports support the use of hyperbaric oxygen therapy (HBO) for the treatment of severe CO poisoning, limited data exist on the effect of HBO during CN poisoning. HBO increases the elimination rate of CO haemoglobin in proportion to the increased oxygen partial pressure and animal experiments have shown that in rats exposed to CN intoxication, HBO can increase the concentration of CN in whole blood.</p> <p>Objective</p> <p>The purpose of the present study was to determine whole blood CN concentrations in fire victims before and after HBO treatment.</p> <p>Materials and methods</p> <p>The patients included were those admitted to the hospital because of CO intoxication, either as fire victims with smoke inhalation injuries or from other exposures to CO. In thirty-seven of these patients we measured CN concentrations in blood samples, using a Conway/microdiffusion technique, before and after HBO. The blood samples consisted of the remaining 2 mL from the arterial blood gas analysis. CN concentration in blood from fire victims was compared to 12 patients from non-fire accidents but otherwise also exposed to CO intoxication.</p> <p>Results</p> <p>The mean WB-CN concentration before patients received HBO did not differ significantly between the two groups of patients (p = 0.42). The difference between WB-CN before and after HBO did not differ significantly between the two groups of patients (p = 0.7). Lactate in plasma before and after did not differ significantly between the two groups of patients. Twelve of the 25 fire patients and one of the non-fire patients had been given a dose of hydroxycobalamin before HBO.</p> <p>Discussion and Conclusion</p> <p>CN concentrations in blood from patients admitted to hospital with CO intoxication and smoke inhalation exposure did not differ significantly from controls. Accordingly, we were not able to detect any changes in CN concentrations in blood after treatment with HBO.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov identifier: NCT00280579</p

The role of the gap junction protein connexin43 in B lymphocyte motility and migration

AbstractThe gap junction family of proteins is widely expressed in mammalian cells and form intercellular channels between adjacent cells, as well as hemichannels, for transport of molecules between the cell and the surrounding environment. In addition, gap junction proteins have recently been implicated as important for the regulation of cell adhesion and migration in a variety of cell types. The gap junction protein connexin43 (Cx43) regulates B lymphocyte adhesion, BCR- and LFA-1-mediated activation of the GTPase Rap1, and cytoskeletal rearrangements resulting in changes to cell shape and membrane spreading. We demonstrate here that the actin cytoskeleton is important for the distribution of Cx43 in the B cell plasma membrane and for other cell processes involving the cytoskeleton. Using shRNA knockdown of Cx43 in B lymphoma cells we show that Cx43 is also necessary for chemokine-mediated Rap 1 activation, motility, CXCL12-directed migration, and movement across an endothelial cell monolayer. These results demonstrate that in addition to its role in B cell spreading, Cx43 is an important regulator of B-cell motility and migration, processes essential for normal B-cell development and immune responses

Perception and Processing of Faces in the Human Brain Is Tuned to Typical Feature Locations.

UNLABELLED: Faces are salient social stimuli whose features attract a stereotypical pattern of fixations. The implications of this gaze behavior for perception and brain activity are largely unknown. Here, we characterize and quantify a retinotopic bias implied by typical gaze behavior toward faces, which leads to eyes and mouth appearing most often in the upper and lower visual field, respectively. We found that the adult human visual system is tuned to these contingencies. In two recognition experiments, recognition performance for isolated face parts was better when they were presented at typical, rather than reversed, visual field locations. The recognition cost of reversed locations was equal to ∼60% of that for whole face inversion in the same sample. Similarly, an fMRI experiment showed that patterns of activity evoked by eye and mouth stimuli in the right inferior occipital gyrus could be separated with significantly higher accuracy when these features were presented at typical, rather than reversed, visual field locations. Our findings demonstrate that human face perception is determined not only by the local position of features within a face context, but by whether features appear at the typical retinotopic location given normal gaze behavior. Such location sensitivity may reflect fine-tuning of category-specific visual processing to retinal input statistics. Our findings further suggest that retinotopic heterogeneity might play a role for face inversion effects and for the understanding of conditions affecting gaze behavior toward faces, such as autism spectrum disorders and congenital prosopagnosia. SIGNIFICANCE STATEMENT: Faces attract our attention and trigger stereotypical patterns of visual fixations, concentrating on inner features, like eyes and mouth. Here we show that the visual system represents face features better when they are shown at retinal positions where they typically fall during natural vision. When facial features were shown at typical (rather than reversed) visual field locations, they were discriminated better by humans and could be decoded with higher accuracy from brain activity patterns in the right occipital face area. This suggests that brain representations of face features do not cover the visual field uniformly. It may help us understand the well-known face-inversion effect and conditions affecting gaze behavior toward faces, such as prosopagnosia and autism spectrum disorders

Development and diagnostic validation of the Brisbane Evidence-Based Language Test

Purpose: To describe the development and determine the diagnostic accuracy of the Brisbane Evidence-Based Language Test in detecting aphasia. Methods: Consecutive acute stroke admissions (n = 100; mean = 66.49y) participated in a single (assessor) blinded cross-sectional study. Index assessment was the ∼45 min Brisbane Evidence-Based Language Test. The Brisbane Evidence-Based Language Test is further divided into four 15–25 min Short Tests: two Foundation Tests (severe impairment), Standard (moderate) and High Level Test (mild). Independent reference standard included the Language Screening Test, Aphasia Screening Test, Comprehensive Aphasia Test and/or Measure for Cognitive-Linguistic Abilities, treating team diagnosis and aphasia referral post-ward discharge. Results: Brisbane Evidence-Based Language Test cut-off score of ≤ 157 demonstrated 80.8% (LR+ =10.9) sensitivity and 92.6% (LR− =0.21) specificity. All Short Tests reported specificities of ≥ 92.6%. Foundation Tests I (cut-off ≤ 61) and II (cut-off ≤ 51) reported lower sensitivity (≥ 57.5%) given their focus on severe conditions. The Standard (cut-off ≤ 90) and High Level Test (cut-off ≤ 78) reported sensitivities of ≥ 72.6%. Conclusion: The Brisbane Evidence-Based Language Test is a sensitive assessment of aphasia. Diagnostically, the High Level Test recorded the highest psychometric capabilities of the Short Tests, equivalent to the full Brisbane Evidence-Based Language Test. The test is available for download from brisbanetest.org. Implications for rehabilitation: Aphasia is a debilitating condition and accurate identification of language disorders is important in healthcare. Language assessment is complex and the accuracy of assessment procedures is dependent upon a variety of factors. The Brisbane Evidence-Based Language Test is a new evidence-based language test specifically designed to adapt to varying patient need, clinical contexts and co-occurring conditions. In this cross-sectional validation study, the Brisbane Evidence-Based Language Test was found to be a sensitive measure for identifying aphasia in stroke