Evidence for nonlinear binding of PAHs to dissolved humic acids

Binding of pyrene, fluoranthene, and phenanthrene to dissolved humic acids (HA) was determined by the fluorescence quenching (FQ) and complexation-flocculation (CF) methods. Determinations by the CF method, using varying contaminant concentrations and a constant HA concentration, yielded nonlinear Freundlich-type isotherms (n = 0.65-0.84). Experiments using both the CF and the FQ methods with varying HA concentrations and a constant contaminant concentration yielded curved "Stern-Volmer"-type plots that also indicate nonlinear binding. These findings suggest that linear partitioning or site complexation in the presence of excess available sites cannot fully describe the interactions of hydrophobic compounds with dissolved humic material. Site-specific hydrophobic interactions at limited interior or external molecular surfaces may be considered.     

Explaining characteristic azeotropic behaviour

An explanation of the formation of minimum-boiling, maximum-boiling and saddle-type azeotropes is given (with illustrative examples) in terms of the molecular interactions in the solutions and in the pure liquids. “Interaction weakening” and “interaction strengthening” effects are defined which tend to be associated with the formation of minimum-boiling and maximum-boiling azeotropes respectively. As defined these effects correspond respectively to positive and to negative values of the interchange energy in regular solution theory, though the concept is considered to be of more general application than is this simple model. When more than two components are present it is possible for both effects to occur leading to the possibility of saddle-type azeotropy.By considering the nature of the intermolecular fones it is possible to predict the kind of azeotope which will be formed, if an azeotrope is formed at all. Although present knowledge of intermolecular fones is far from complete, enough is known to enable this prediction to be made in many cases. The more exacting question of whether or not an azeotope will be formed cannot yet be answered with the same certainty partly because of the lack of a completely satisfactory model of the liquid state.     

Advanced methods for displays and remote control of robots

An in-depth evaluation of the usability and situation awareness performance of different displays and destination controls of robots are presented. In two experiments we evaluate the way information is presented to the operator and assess different means for controlling the robot. Our study compares three types of displays: a “blocks” display, a HUD (head-up display), and a radar display, and two types of controls: touch screen and hand gestures. The HUD demonstrated better performance when compared to the blocks display and was perceived to have greater usability compared to the radar display. The HUD was also found to be more useful when the operation of the robot was more difficult, i.e., when using the hand-gesture method. The experiments also pointed to the importance of using a wide viewing angle to minimize distortion and for easier coping with the difficulties of locating objects in the field of view margins. The touch screen was found to be superior in terms of both objective performance and its perceived usability. No differences were found between the displays and the controllers in terms of situation awareness. This research sheds light on the preferred display type and controlling method for operating robots from a distance, making it easier to cope with the challenges of operating such systems.     

Ranking sensors using an adaptive fuzzy logic algorithm

A procedure to rank sensors according to their noise rates was developed based on an adaptive fuzzy logic algorithm for sensor fusion. No a priori knowledge of the sensors performance is assumed. Simulation analysis indicated 83.33% successful ranking with noise rates up to 50%. In an indoor experiment with a mobile robot equipped with three logical sensors, 88% of the rankings were correct. The ranking procedure also indicates the ranking results success probability.     

Kernel machines for current status data

Machine Learning - In survival analysis, estimating the failure time distribution is an important and difficult task, since usually the data is subject to censoring. Specifically, in this paper we...     

Gauging of Cytochrome c Structural Fluctuation by Time-Resolved Proton Pulse

A brief proton pulse technique, based on photo-excitation of pyranine, was employed for measuring the protonation dynamics of cytochrome c in aqueous solutions. Time-resolved monitoring of the protonation state of the pyranine anion yielded detailed information from which the temporal state protonation of the surface carboxylates and histidine residues were deduced. The surface groups were found to be coupled by electrostatic interaction where the state of protonation of one affects the pK of the others. In the same sense, altering the charge distribution of a protein by a redox reaction affects the reactivity of the surface groups with protons in the bulk. The surface groups can exchange protons among themselves at a very high rate. The velocities of these reactions are functions of the connectivity between the proton binding sites. A single proton exchange reaction between the surface groups could be identified as the proton exchange between H26 and E44. The reaction is fast and affected by the redox state of the protein. It is proposed that the enhanced rate of this reaction is coupled with transient conformational changes that are not noticeable in time-averaging measurements such as X-ray diffraction or NMR.     

On the Effective Deployment of Functional Formal Verification

We examine IBM's exploitation of formal verification using RuleBase—a formal verification tool developed by the IBM Haifa Research Laboratory. The goal of the paper is methodological. We identify an integrated methodology for the deployment of formal verification which involves three complementary modes: architectural verification, block-level verification, and design exploration.     

A Human-Robot Collaborative Reinforcement Learning Algorithm

This paper presents a new reinforcement learning algorithm that enables collaborative learning between a robot and a human. The algorithm which is based on the Q(λ) approach expedites the learning process by taking advantage of human intelligence and expertise. The algorithm denoted as CQ(λ) provides the robot with self awareness to adaptively switch its collaboration level from autonomous (self performing, the robot decides which actions to take, according to its learning function) to semi-autonomous (a human advisor guides the robot and the robot combines this knowledge into its learning function). This awareness is represented by a self test of its learning performance. The approach of variable autonomy is demonstrated and evaluated using a fixed-arm robot for finding the optimal shaking policy to empty the contents of a plastic bag. A comparison between the CQ(λ) and the traditional Q(λ)-reinforcement learning algorithm, resulted in faster convergence for the CQ(λ) collaborative reinforcement learning algorithm.     

Diurnal patterns of micropollutants concentrations in domestic greywater

In recent years, much interest has been given to presence of micropollutants in municipal wastewater, some of which are suspected to be endocrine disruptors, toxic or carcinogenic. Much less attention has been paid to their presence in greywater. The present research studies the diurnal patterns of micropollutants in greywater and computes their daily loads. Monitoring was carried-out using auto-controlled sampling system, designed to overcome the erratic greywater generation. Two main generation periods were identified: morning (5:00–11:00) and evening-night (18:00–2:00), contributing about 20% and >50% of daily greywater discharge, respectively. Average specific daily greywater discharge was 57 L p^?1d^?1, which matches reported value for greywater generated by showers and washbasins in Israel. The most frequently detected micropollutants in this study were methylparben (preservative), galaxolide (fragrance) and oxybenzone (UV-filter), which are common ingredients in many personal care-products. Their daily loads were 2, 840, 1, 887 and 728 µg p^?1d^?1, respectively.     

Chemo-Enzymatic Fluorescence Labeling Of Genomic DNA For Simultaneous Detection Of Global 5-Methylcytosine And 5-Hydroxymethylcytosine**

5-Methylcytosine and 5-hydroxymethylcytosine are epigenetic modifications involved in gene regulation and cancer. We present a new, simple, and high-throughput platform for multi-color epigenetic analysis. The novelty of our approach is the ability to multiplex methylation and de-methylation signals in the same assay. We utilize an engineered methyltransferase enzyme that recognizes and labels all unmodified CpG sites with a fluorescent cofactor. In combination with the already established labeling of the de-methylation mark 5-hydroxymethylcytosine via enzymatic glycosylation, we obtained a robust platform for simultaneous epigenetic analysis of these marks. We assessed the global epigenetic levels in multiple samples of colorectal cancer and observed a 3.5-fold reduction in 5hmC levels but no change in DNA methylation levels between sick and healthy individuals. We also measured epigenetic modifications in chronic lymphocytic leukemia and observed a decrease in both modification levels (5-hydroxymethylcytosine: whole blood 30 %; peripheral blood mononuclear cells (PBMCs) 40 %. 5-methylcytosine: whole blood 53 %; PBMCs 48 %). Our findings propose using a simple blood test as a viable method for analysis, simplifying sample handling in diagnostics. Importantly, our results highlight the assay‘s potential for epigenetic evaluation of clinical samples, benefiting research and patient management.