Characteristics of Bitcoin Transactions on Cryptomarkets

Cryptomarkets (or darknet markets) are commercial hidden-service websites that operate on The Onion Router (Tor) anonymity network. Cryptomarkets accept primarily bitcoin as payment since bitcoin is pseudonymous. Understanding bitcoin transaction patterns in cryptomarkets is important for analyzing vulnerabilities of privacy protection models in cryptocurrecies. It is also important for law enforcement to track illicit online crime activities in cryptomarkets. In this paper, we discover interesting characteristics of bitcoin transaction patterns in cryptomarkets. The results demonstrate that the privacy protection mechanism in cryptomarkets and bitcoin is vulnerable. Adversaries can easily gain valuable information for analyzing trading activities in cryptomarkets

Relating Neuronal to Behavioral Performance: Variability of Optomotor Responses in the Blowfly

Behavioral responses of an animal vary even when they are elicited by the same stimulus. This variability is due to stochastic processes within the nervous system and to the changing internal states of the animal. To what extent does the variability of neuronal responses account for the overall variability at the behavioral level? To address this question we evaluate the neuronal variability at the output stage of the blowfly's (Calliphora vicina) visual system by recording from motion-sensitive interneurons mediating head optomotor responses. By means of a simple modelling approach representing the sensory-motor transformation, we predict head movements on the basis of the recorded responses of motion-sensitive neurons and compare the variability of the predicted head movements with that of the observed ones. Large gain changes of optomotor head movements have previously been shown to go along with changes in the animals' activity state. Our modelling approach substantiates that these gain changes are imposed downstream of the motion-sensitive neurons of the visual system. Moreover, since predicted head movements are clearly more reliable than those actually observed, we conclude that substantial variability is introduced downstream of the visual system

Design of a ligand suitable for sensitive uranyl analysis in aqueous solutions

<div><p>Several ligands were designed as plausible reagents for the spectrophotometric analysis of uranyl in aqueous solutions. The ligand  = 3,3′-(ethane-1,2-diylbis(methylazanediyl))bis(methylene)bis(4-hydroxybenzenesulfonate) was found to fit best the requirements. The results point out that carboxylate substituents compete with the phenolate substituents as binding sites to the central uranium cation and therefore decrease the usefulness of ligands containing both carboxylate and phenolate substituents as analytical spectrophotometric reagents.</p></div

Different oxidation mechanisms of Mn^II(polyphosphate)_n by the radicals and

<p>The kinetics and mechanisms of the oxidation of and of by the biological relevant radicals and were studied. The rate constants of the oxidations by both radicals are faster for the complexes than for the complexes, though the redox potentials predict the reverse order of reactivity. Surprisingly, the results point out that these two radicals react via different mechanisms. Thus, the increase in the concentration of the ligands decreases the rate constants of the oxidations by , whereas it increases the rate constants of the oxidation by . These results point out that these radicals behave differently though both are inner-sphere oxidants. The plausible mechanisms of reaction of these radicals are discussed.</p