Model of the Belousov-Zhabotinsky reaction

The article describes results of the modified model of the Belousov-Zhabotinsky reaction, which resembles rather well the limit set observed upon experimental performance of the reaction in the Petri dish. We discuss the concept of the ignition of circular waves and show that only the asymmetrical ignition leads to the formation of spiral structures. From the qualitative assumptions on the behavior of dynamic systems, we conclude that the Belousov-Zhabotinsky reaction likely forms a regular grid.Comment: 17 pages, 12 figure

The SiC Problem: Astronomical and Meteoritic Evidence

Presolar grains of silicon carbide, found in meteorites and interpreted as having had an origin around carbon stars from their isotopic composition, have all been found to be of the β-SiC polytype. Yet, to date, fits to the 11.3 μm SiC emission band of carbon stars had been obtained only for α-SiC grains. We present thin-film infrared (IR) absorption spectra that were measured in a diamond-anvil cell for both the α- and β-polymorphs of synthetic SiC, and we compare the results with previously published spectra that were taken using the KBr matrix method. We find that our thin-film spectra have positions nearly identical to those obtained previously from finely ground samples in KBr. Hence, we show that this discrepancy has arisen from inappropriate "KBr corrections" having been made to laboratory spectra of SiC particles dispersed in KBr matrices. We refitted a sample of carbon star mid-IR spectra, using laboratory data with no KBr correction applied, and show that β-SiC grains fitted the observations while α-SiC grains did not. The discrepancy between meteoritic and astronomical identifications of the SiC type is therefore removed. This work shows that the diamond-anvil cell, thin-film method can be used to produce mineral spectra that are applicable to cosmic environments without further manipulation

Silicon carbide: The problem with laboratory spectra

The interpretation of astronomical observations of infrared (IR) silicon carbide (SiC) features in the spectra of carbon stars have revealed discrepancies between the work of astronomers and that of meteoriticists. The silicon carbide observed around carbon stars has been attributed to one type of SiC (α) while meteoritic samples believed to have formed around such stars are of another type of SiC (β). The key to solving this problem has been to understand the sources of laboratory data used by astronomers in order to interpret the IR spectra. Through comparison of thin film IR absorption spectra and spectra taken using finely ground samples dispersed in potassium bromide (KBr) pellets we show that the previously invoked ``KBr matrix-correction'' is unnecessary for powder dispersions obtained from very fine grain sizes of SiC. Comparison of our data and previous measurements show that dust around carbon stars is β-SiC, consistent with laboratory studies of presolar grains in meteorites. The implications of these findings affect twenty years of work. The IR spectroscopic laboratory data used by astronomers to identify dust species in space must be carefully scrutinized to ensure that the KBr correction is not responsible for further misattributions of minerals in astronomical dust features

Successful treatment of high-flow priapism with radiologic transcatheter embolization of the internal pudendal artery: A case report

Priapism, a relatively uncommon disorder, is divided into ischemic (veno-occlusive, low flow) painful priapism and nonischemic (arterial, high flow) painless priapism.. We report our successful treatment of arterial priapism by means of radiologic selective transcatheter embolization of the internal pudendal artery using micro coil

Records of Diatoms and Physicochemical Parameters of Seasonal Ponds in Zaria- Northern Nigeria

A study of diatoms species composition, associated with four ponds in Zaria, Northern Nigeria was carried out between November 2005–January 2006 and June–August 2006. Twenty three taxa of diatoms were recorded in the study. Multivariate analysis showed that there were significant positive and negative relationships (P < 0.05) between some physicochemical parameters and diatom species in these ponds. CCA results showed that Synedra and Actinocyclus were closely associated with TDS, DO and water hardness; Nitzschia, Frustulia, Navicula and Coscinodiscus with NO-N and alkalinity; and Cyclotella, Tabellaria and Achnanthes with phosphate phosphorus 3 levels

Separating Reflection and Transmission Images in the Wild

The reflections caused by common semi-reflectors, such as glass windows, can impact the performance of computer vision algorithms. State-of-the-art methods can remove reflections on synthetic data and in controlled scenarios. However, they are based on strong assumptions and do not generalize well to real-world images. Contrary to a common misconception, real-world images are challenging even when polarization information is used. We present a deep learning approach to separate the reflected and the transmitted components of the recorded irradiance, which explicitly uses the polarization properties of light. To train it, we introduce an accurate synthetic data generation pipeline, which simulates realistic reflections, including those generated by curved and non-ideal surfaces, non-static scenes, and high-dynamic-range scenes.Comment: accepted at ECCV 201

Privacy Preserving Threat Hunting in Smart Home Environments

The recent proliferation of smart home environments offers new and transformative circumstances for various domains with a commitment to enhancing the quality of life and experience. Most of these environments combine different gadgets offered by multiple stakeholders in a dynamic and decentralized manner, which in turn presents new challenges from the perspective of digital investigation. In addition, a plentiful amount of data records got generated because of the day to day interactions between these gadgets and homeowners, which poses difficulty in managing and analyzing such data. The analysts should endorse new digital investigation approaches to tackle the current limitations in traditional approaches when used in these environments. The digital evidence in such environments can be found inside the records of logfiles that store the historical events occurred inside the smart home. Threat hunting can leverage the collective nature of these gadgets to gain deeper insights into the best way for responding to new threats, which in turn can be valuable in reducing the impact of breaches. Nevertheless, this approach depends mainly on the readiness of smart homeowners to share their own personal usage logs that have been extracted from their smart home environments. However, they might disincline to employ such service due to the sensitive nature of the information logged by their personal gateways. In this paper, we presented an approach to enable smart homeowners to share their usage logs in a privacy preserving manner. A distributed threat hunting approach has been developed to permit the composition of diverse threat classes without revealing the logged records to other involved parties. Furthermore, a scenario was proposed to depict a proactive threat Intelligence sharing for the detection of potential threats in smart home environments with some experimental results.Comment: In Proc. the International Conference on Advances in Cyber Security, Penang, Malaysia, July 201

Simultaneous quantification of active carbon- and nitrogen-fixing communities and estimation of fixation rates using fluorescence in situ hybridization and flow cytometry

© 2014, American Society for Microbiology. Understanding the interconnectivity of oceanic carbon and nitrogen cycles, specifically carbon and nitrogen fixation, is essential in elucidating the fate and distribution of carbon in the ocean. Traditional techniques measure either organism abundance or biochemical rates. As such, measurements are performed on separate samples and on different time scales. Here, we developed a method to simultaneously quantify organisms while estimating rates of fixation across time and space for both carbon and nitrogen. Tyramide signal amplification fluorescence in situ hybridization (TSA-FISH) of mRNA for functionally specific oligonucleotide probes for rbcL (ribulose-1,5-bisphosphate carboxylase/oxygenase; carbon fixation) and nifH (nitrogenase; nitrogen fixation) was combined with flow cytometry to measure abundance and estimate activity. Cultured samples representing a diversity of phytoplankton (cyanobacteria, coccolithophores, chlorophytes, diatoms, and dinoflagellates), as well as environmental samples from the open ocean (Gulf of Mexico, USA, and southeastern Indian Ocean, Australia) and an estuary (Galveston Bay, Texas, USA), were successfully hybridized. Strong correlations between positively tagged community abundance and 14C/15N measurements are presented. We propose that these methods can be used to estimate carbon and nitrogen fixation in environmental communities. The utilization of mRNA TSA-FISH to detect multiple active microbial functions within the same sample will offer increased understanding of important biogeochemical cycles in the ocean