Isolation and Characterization of Two Novel Siphoviruses Novomoskovsk and Bolokhovo,Encoding Polysaccharide Depolymerases Active against Bacillus pumilus

This study describes two novel bacteriophages infecting members of the Bacillus pumilus group. Even though members of the group are not recognized as pathogenic, several strains belonging to the group have been reported to cause infectious diseases in plants, animals and humans. Bacillus pumilus group species are highly resistant to ultraviolet radiation and capable of forming biofilms, which complicates their eradication. Bacteriophages Novomoskovsk and Bolokhovo were isolated from soil samples. Genome sequencing and phylogenetic analysis revealed that the phages represent two new species of the genus Andromedavirus (class Caudoviricetes). The phages remained stable in a wide range of temperatures and pH values. A host range test showed that the phages specifically infect various strains of B. pumilus. The phages form clear plaques surrounded by halos. Both phages Novomoskovsk and Bolokhovo encode proteins with pectin lyase domains—Putative depolymerases. Obtained in a purified recombinant form, the proteins produced lysis zones on the lawn of a B. pumilus strain. This suggests that Novomoskovsk and Bolokhovo may be effective for the eradication of B. pumilus biofilms.     

An empirical investigation into the difficulties experienced by visually impaired Internet users

In this paper, an empirical based study is described which has been conducted to gain a deeper understanding of the challenges faced by the visually impaired community when accessing the Web. The study, involving 30 blind and partially sighted computer users, has identified navigation strategies, perceptions of page layout and graphics using assistive devices such as screen readers. Analysis of the data has revealed that current assistive technologies impose navigational constraints and provide limited information on web page layout. Conveying additional spatial information could enhance the exploration process for visually impaired Internet users. It could also assist the process of collaboration between blind and sighted users when performing web-based tasks. The findings from the survey have informed the development of a non-visual interface, which uses the benefits of multimodal technologies to present spatial and navigational cues to the user.     

Do Dogs (Canis familiaris) Understand Invisible Displacement?

Domestic dogs (Canis familiaris) perform above chance on invisible displacement tasks despite showing few other signs of possessing the necessary representational abilities. Four experiments investigated how dogs find an object that has been hidden in 1 of 3 opaque boxes. Dogs passed the task under a variety of control conditions, but only if the device used to displace the object ended up adjacent to the target box after the displacement. These results suggest that the search behavior of dogs was guided by simple associative rules rather than mental representation of the object's past trajectory. In contrast, Experiment 5 found that on the same task, 18- and 24-month-old children showed no disparity between trials in which the displacement device was adjacent or nonadjacent to the target box. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of noise parameter extraction methods

The influence of the algorithm used for noise parameter fitting on the accuracy of the microwave noise parameter measurements is investigated. Five different commonly used algorithms are compared by a statistical analysis including instrument accuracy specifications. Some of these algorithms are found to be more efficient in terms of available accuracy and computer time. The best predicted available accuracies reported betwen 4 and 20 GHz for each noise parameter compare well with observed accuracies on noise parameter measurements performed with a dedicated test set on a noise standard made of a passive two-port. The accuracy on minimum noise figure is found to be 0.1 dB maximum     

Determination of heavy metals in milk by potentiometric stripping analysis using a home-made flow cell

A method is described for sensitive and reliable determination of trace concentrations of cadmium, lead and copper in real samples by stripping potentiometry with a home-made flow cell. The selection of the experimental conditions was made using experimental design methodology. The optimum conditions for the method include an acetic acid–acetate buffer mixture (pH 3.4) as supporting electrolyte, an electrolysis potential of −1.1 V and a flow rate of 3 ml min⁻¹. The detection limits were 6.51 × 10⁻¹⁰ mol l⁻¹ for cadmium, 4.60 × 10⁻¹⁰ mol l⁻¹ for lead and 8.59 × 10⁻¹⁰ mol l⁻¹ for copper, with an electrolysis time of 900 s. The relative standard deviations at this concentration level were 0.038, 0.086 and 0.095, respectively. In order to check the analytical accuracy, standard solutions have been used and recoveries close to 100% were obtained. The method was successfully applied to the determination of cadmium, lead and copper in powdered milk, using the method of standard additions.     

Structure dependent charging process in RF MEMS capacitive switches

The paper investigates the dependence of charging process on the dielectric charging of radiation induced defects in Si₃N₄ and SiO₂ dielectric films, which are used in RF-MEMS switches. The radiation has been performed with 5 MeV alpha particles. The assessment has been carried out in Metal-Insulator-Metal capacitors with the thermally stimulated depolarization currents and discharge current transient methods. This allowed monitoring the defects introduction as a function of radiation fluence. The defects electrical characteristics that are the activation energy and corresponding depolarization time constant were determined from the evolution of the thermally stimulated current spectra and the transient response of discharge currents at different temperatures.     

Accuracy of confidence ratings associated with general knowledge and eyewitness memory.

The confidence–accuracy (C–A) relation for general knowledge (GK) and eyewitness memory (EM) was compared in both within- and between-Ss analyses. Researchers in the cognitive tradition tend to use within-Ss designs and to find moderately positive C–A relations, whereas those in the forensic tradition tend to use between-Ss designs and to find no relations. 80 Ss took part in 1 of 2 conditions, EM or GK. No difference between conditions was found on the within-Ss measure of the C–A relation, but there was differentiation with a between-Ss measure. There was a strong positive C–A correlation (r?=?.58, p?r?=?–.11, ns). One source of this difference may be the differing opportunities for calibration offered by the 2 kinds of memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)