Change in the polarization of partially coherent electromagnetic beams propagating through the turbulent atmosphere

We study the changes in the degree of polarization of an electromagnetic Gaussian Schell-model beam, as the beam propagates through the turbulent atmosphere. We demonstrate that, within the framework of the Tatarskii model of the turbulent atmosphere, the degree of polarization of the beam changes appreciably at relatively short propagation distances in the atmosphere. In the long-propagation distance limit, however, we find that the degree of polarization of the beam tends to the value that it has in the source plane.     

Effects of linear non-image-forming devices on spectra and on coherence and polarization properties of stochastic electromagnetic beams: part I: general theory

The classic theoretical techniques of polarization optics are the Jones calculus and the Stokes-Mueller calculus. Both deal with transmission of certain ‘one-point’ quantities, which are associated with a light beam. Recently ‘two-point’ quantities were introduced, which are the elements of a 2?×?2 cross-spectral density matrix that characterizes the correlations at two points in a beam or which are expressible in terms of them. Unlike the quantities with which the Jones and the Stokes calculus deal, these generalized quantities contain information not only about the polarization properties of the beam but also about its coherence properties. In this paper we present a generalization of the Jones calculus and of the Stokes-Mueller calculus for transformations of the new two-point quantities by linear non-image-forming devices. They may act on the beam in a deterministic or in a random manner.     

Psychology Training Directors' Views of Trainees' Readiness to Practice Independently.

When are psychology trainees ready to practice independently? This question has been debated extensively during the past few years. To contribute to this debate, a national survey of training directors of academic programs, predoctoral internships, and postdoctoral fellowships was conducted. The study explored training directors' views regarding the examinations and supervisory hours necessary to become an independent practitioner. The study found that training directors were divided in their opinions of when trainees are competent to practice independently. Academic training directors believed that trainees are ready for independent practice earlier in the training sequence than internship and postdoctoral training directors. The implications for conflicting views are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress corrosion cracking behaviour of stainless steels with respect to their use in architecture,part 1: corrosion in the active state

Unexpected failures on 18/8 CrNi and 17/12/2 CrNiMo steels in indoor swimming pool atmospheres made it necessary to reinvestigate chloride induced stress corrosion cracking (SCC). SCC in the active state was investigated on stainless steels 1.3974, 1.4301, 1.4303, 1.4439, 1.4462, 1.4522, 1.4539 and 1.4571 by testing under constant load at temperatures up to 50°C. Selected tests were performed on the material with the highest SCC susceptibility, 1.4301, in solutions with different concentrations of hydrochloric acid and sodium chloride. SCC was only observed in critical ranges of hydrogen-ion concentration and only in conjunction with pronounced general corrosion. In a solution with c(HCl) = 1.0 mol/l and c(NaCl) = 0.5 mol/l, which had proved to be highly SCC-inducing, the effects of different parameters on SCC behaviour were studied. Temperature, stress level and degree of cold deformation exerted only a secondary influence, in contrast to alloy composition: austenitic steels containing about 10% nickel (1.4301, 1.4303, 1.4571) exhibited very pronounced SCC. The other materials with nickel contents distinctively higher or lower proved, respectively, to be less susceptible or resistant to SCC. Thus, the same effect of nickel content was observed as is known for resistance to chloride induced SCC in the passive state. All materials were prone to pronounced general corrosion. The corrosion phenomena observed were completely different from the swimming pool failures reported.     

Psychology Training Directors' Views of Number of Practicum Hours Necessary Prior to Internship Application.

A national survey of training directors of academic programs, predoctoral internships, and postdoctoral fellowships was conducted to explore what constitutes an adequate number of practicum hours necessary to apply for internship. Training directors agreed that minimum standard hours should be set but differed on what those hours should be, with academic training directors endorsing fewer hours than directors of predoctoral internships and postdoctoral fellowships. The results raise questions about what is a practicum hour and suggest a need to obtain consensus about minimum standards and the possibility of a competency-based approach rather than emphasizing hours of practicum experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comment from the editorial team.

Introduces this first edition of Training and Education in Professional Psychology, and presents a brief history of its development. In addition, many of the individuals involved in the Journal's development are recognized. The editorial team of TEPP hopes that the journal will provide a professional forum for psychologists to exchange ideas and contribute thoughtful investigations about the challenges, the discussions, and the future direction of education and training in psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The management of sexual feelings in therapy.

This research project examined the incidence, experience, salient features, and management of sexual attraction between psychologists and clients and assessed 386 American Psychological Association member psychologists who work in university counseling centers. Only 12% reported never having been attracted to any client, and 96% never had acted out sexually against a client. Almost half reported that their feelings of attraction benefited the therapy process, and 43% reported negative consequences. 60% sought consultation or supervision to discuss this attraction. The results of this study support the need for increased awareness and education in this area. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Coordination chemistry of a para-tert-octylcalix[4]arene fitted with phosphinoyl pendant arms towards 4f-elements: Extraction,synergism, separation

The solvent extraction of trivalent lanthanoids (Ln³⁺) by 5,11,17,23-tetra(para-tert-octyl)-25,26,27,28-tetrakis(dimethylphosphinoylmethoxy)calix[4]arene (S), bearing four phosphine oxide donor groups at the lower rim as synergistic agent in combination with a 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (HP) in CHCl₃ from chloride medium at µ = 0.1 was quantitatively described in the form of LnP₃·S complexes. The role of the synergistic agent on the extraction process was discussed. The values of the separation factors have been evaluated. On the basis of the IR and NMR spectra the stoichiometry and the structure of the solid mixed complex of Eu(III) with HP and S were proposed.     

Label-free electrochemical monitoring of DNA ligase activity

This study presents a simple, label-free electrochemical technique for the monitoring of DNA ligase activity. DNA ligases are enzymes that catalyze joining of breaks in the backbone of DNA and are of significant scientific interest due to their essential nature in DNA metabolism and their importance to a range of molecular biological methodologies. The electrochemical behavior of DNA at mercury and some amalgam electrodes is strongly influenced by its backbone structure, allowing a perfect discrimination between DNA molecules containing or lacking free ends. This variation in electrochemical behavior has been utilized previously for a sensitive detection of DNA damage involving the sugar-phosphate backbone breakage. Here we show that the same principle can be utilized for monitoring of a reverse process, i.e., the repair of strand breaks by action of the DNA ligases. We demonstrate applications of the electrochemical technique for a distinction between ligatable and unligatable breaks in plasmid DNA using T4 DNA ligase, as well as for studies of the DNA backbone-joining activity in recombinant fragments of E. coli DNA ligase.