Monte Carlo Simulation of Deffuant opinion dynamics with quality differences

In this work the consequences of different opinion qualities in the Deffuant model were examined. If these qualities are randomly distributed, no different behavior was observed. In contrast to that, systematically assigned qualities had strong effects to the final opinion distribution. There was a high probability that the strongest opinion was one with a high quality. Furthermore, under the same conditions, this major opinion was much stronger than in the models without systematic differences. Finally, a society with systematic quality differences needed more tolerance to form a complete consensus than one without or with unsystematic ones.Comment: 8 pages including 5 space-consuming figures, fir Int. J. Mod. Phys. C 15/1

Accelerated hardware video object segmentation: From foreground detection to connected components labelling

This is the preprint version of the Article - Copyright @ 2010 ElsevierThis paper demonstrates the use of a single-chip FPGA for the segmentation of moving objects in a video sequence. The system maintains highly accurate background models, and integrates the detection of foreground pixels with the labelling of objects using a connected components algorithm. The background models are based on 24-bit RGB values and 8-bit gray scale intensity values. A multimodal background differencing algorithm is presented, using a single FPGA chip and four blocks of RAM. The real-time connected component labelling algorithm, also designed for FPGA implementation, run-length encodes the output of the background subtraction, and performs connected component analysis on this representation. The run-length encoding, together with other parts of the algorithm, is performed in parallel; sequential operations are minimized as the number of run-lengths are typically less than the number of pixels. The two algorithms are pipelined together for maximum efficiency

Searching for T Dwarfs Within the Spitzer XFLS

One of the main advantages of the Spitzer Space Telescope are the Extragalactic and Galactic First Look Survey (XFLS, FLS) created during the first months of nominal operations. The IRAC instrument, especially, allowed simultaneous observations in multiple bands of these large areas of sky available to the astronomical community. We have decided to exploit the XFLS for a brown dwarf search, as well as the GFLS. In this paper, we report on the progress on our search within the XFLS

Gender-specific prevalence of pilonidal sinus disease over time: A systematic review and meta-analysis.

BACKGROUND Gender-specific risk factors have been suggested to promote a fourfold higher incidence of pilonidal sinus disease (PSD) in male as compared to female patients. However, in recent decades there has been an apparent shift towards an increasing prevalence of PSD in women, as body weight and other risk factors influence the disease. We aimed at determining whether PSD prevalence actually changed in men and women over time. METHODS Following PRISMA guidelines (PROSPERO ID: 42016051588), databases were systematically searched. Papers reporting on PSD published between 1833 and 2018 in English, French, German, Italian and Spanish containing precise numbers of male and female participants were selected for analysis. Gender-specific prevalence of PSD over several decades was the main outcome measure. RESULTS We screened 679 studies reporting on 104 055 patients and found that the male/female ratio in patients with PSD has remained constant over time, with women being affected in about 20% of all PSD cases (I2  = 96.18%; meta-regression p < 0.001). CONCLUSION While the prevalence of PSD has risen over the past decades, the ratio between affected males and affected females has remained constant, with women invariably representing about 20% of patients despite wide ranging socioeconomic and behavioural changes

Extreme event ecology needs proactive funding

Commentary: Extreme events such as wildfires, hurricanes, and floods have increased in frequency and intensity. It is no longer a question of if, but rather when and where these events will occur (Stott 2016), with adverse impacts on essential ecosystemservices including clean water, harvestable materials, and carbon sequestration. In some cases, extreme events such as wildfires may have positive impacts on populations and ecosystems. Managing these impacts requires understanding how environmental context as well as ecosystem and disturbance characteristics drive system responses (Hogan et al. 2020). However, funding for ecological extreme events research, such as through the US National Science Foundation’s (NSF’s) RAPID program, is typically reactive. Pre-event data, a RAPID prerequisite, aretypically lacking or only sporadically available, and case studies of extreme events often arise from chance disturbances at existing long-term research sites. This reactive stochastic approach has seeded the literature with unplanned case studies describing individual events. While useful for meta-analyses (eg Patrick et al. 2022), such studies provide limited spatiotemporal inference and predictive capacity. Prioritizing the study of extreme events and empirically testing fundamental concepts in disturbance ecology is paramount (Aoki et al. 2022). (...

Using drift scans to improve astrometry with Spitzer

The Spitzer Space Telescope Infrared Array Camera (IRAC) is the only space-based instrument currently capable of continuous long duration monitoring of brown dwarfs to detect variability and characterize their atmospheres. Any such studies are limited, however, by the accuracy to which we know the positions and distances to these targets (most of which are newly discovered and therefore do not yet have multiple epochs of astrometric data). To that end, we have begun a new initiative to adapt the astrometric drift scanning technique employed by the Hubble Space Telescope to enhance Spitzer measurements of parallaxes and proper motions of brown dwarfs and other targets. A suite of images are taken with a set of sources scanned across the array. This technique reduces random noise by coaddition, and because each target covers multiple pixels we are able to average over residual instrumental distortion and intra-pixel variations. Although these benefits can be realized with appropriate dithering, scanning is much more effcient because we can take data concurrently with the spacecraft motion, covering many pixels without waiting to reposition and settle. In this contribution we demonstrate that the observing mode works and describe our software for analyzing the observations. We outline ongoing efforts towards simultaneously solving for source position and residual distortion. Initial testing shows a factor of more than 2 improvement in the astrometric precision can be obtained with Spitzer. We anticipate being able to measure parallaxes for sources out to about 50 pc, increasing the volume surveyed by a factor of 100 and enabling luminosity measurements of the young population of brown dwarfs in the β Pictoris moving group. This observing mode will be ready for public use around Winter of 2015

Transient Dynamics of Sparsely Connected Hopfield Neural Networks with Arbitrary Degree Distributions

Using probabilistic approach, the transient dynamics of sparsely connected Hopfield neural networks is studied for arbitrary degree distributions. A recursive scheme is developed to determine the time evolution of overlap parameters. As illustrative examples, the explicit calculations of dynamics for networks with binomial, power-law, and uniform degree distribution are performed. The results are good agreement with the extensive numerical simulations. It indicates that with the same average degree, there is a gradual improvement of network performance with increasing sharpness of its degree distribution, and the most efficient degree distribution for global storage of patterns is the delta function.Comment: 11 pages, 5 figures. Any comments are favore

The Role of the Immune Response in the Pathogenesis of Thyroid Eye Disease: A Reassessment

Background Although thyroid eye disease is a common complication of Graves’ disease, the pathogenesis of the orbital disease is poorly understood. Most authorities implicate the immune response as an important causal factor. We sought to clarify pathogenesis by using gene expression microarray. Methods An international consortium of ocular pathologists and orbital surgeons contributed formalin fixed orbital biopsies. RNA was extracted from orbital tissue from 20 healthy controls, 25 patients with thyroid eye disease (TED), 25 patients with nonspecific orbital inflammation (NSOI), 7 patients with sarcoidosis and 6 patients with granulomatosis with polyangiitis (GPA). Tissue was divided into a discovery set and a validation set. Gene expression was quantified using Affymetrix U133 Plus 2.0 microarrays which include 54,000 probe sets. Results Principal component analysis showed that gene expression from tissue from patients with TED more closely resembled gene expression from healthy control tissue in comparison to gene expression characteristic of sarcoidosis, NSOI, or granulomatosis with polyangiitis. Unsupervised cluster dendrograms further indicated the similarity between TED and healthy controls. Heat maps based on gene expression for cytokines, chemokines, or their receptors showed that these inflammatory markers were associated with NSOI, sarcoidosis, or GPA much more frequently than with TED. Conclusion This is the first study to compare gene expression in TED to gene expression associated with other causes of exophthalmos. The juxtaposition shows that inflammatory markers are far less characteristic of TED relative to other orbital inflammatory diseases

Spitzer Infrared Array Camera (IRAC) Pipeline: final modifications and lessons learned

In more than ten years of operations, the Spitzer Space Telescope has conducted a wide range of investigations from observing nearby asteroids to probing atmospheric properties of exoplanets to measuring masses of the most distance galaxies. Observations using the Infrared Array Camera (IRAC) at 3.6 and 4.5um will continue through mid-2019 when the James Webb Space Telescope will succeed Spitzer. In anticipation of the eventual end of the mission, the basic calibrated data reduction pipeline designed to produce flux-calibrated images has been finalized and used to reprocess all the data taken during the Spitzer warm mission. We discuss all final modifications made to the pipeline