Power supplies for plasma column control in the COMPASS tokamak

The main magnetic fields in COMPASS – i.e. The Toroidal, Magnetising, Equilibrium, and Shaping Fields – are created by a set of four corresponding thyristor power supplies controlled in a 0.5 ms loop.The plasma position has to be controlled both radially and vertically by two additional magnetic fields provided by two fast amplifiers (FAs) based on MOSFET technology, each supplying ±100 V and up to ±5 kA.Currently, an ongoing project aims at ELM triggering by fast changes of the vertical position of the plasma column, also referred to as vertical kicks. For this purpose, a new Vertical Kicks Power Supply (VKPS) capable of quick change of vertical plasma position is being constructed. This power supply should operate at up to 1.2 kV with switching frequency up to 5 kHz. It is designed as a H-bridge but based on IGBT transistors which can be operated at higher voltages than MOSFETs.In this paper, we focus on the FAs and VKPS engineering design and required output parameters. Both the power supplies are based on modern components with highest available ratings in their categories. Unique design of the power supplies takes advantage of the short duration of the COMPASS discharge by overloading the transistors above their maximal steady-state rating.The FA is regularly operating, so that in addition to describing its design, we also describe the achieved performance parameters. Finally, the common controller unit, communication, and error handling is described.     

Polar compounds dominate in vitro effects of sediment extracts

Sediment extracts from three polluted sites of the river Elbe basin were fractionated using a novel online fractionation procedure. Resulting fractions were screened for mutagenic, aryl hydrocarbon receptor (AhR)-mediated, transthyretin (TTR)-binding, and estrogenic activities and their potency to inhibit gap junctional intercellular communication (GJIC) to compare toxicity patterns and identify priority fractions. Additionally, more than 200 compounds and compound classes were identified using GC-MS/MS, LC-MS/MS, and HPLC-DAD methods. For all investigated end points, major activities were found in polar fractions, which are defined here as fractions containing dominantly compounds with at least one polar functional group. Nonpolar PAH fractions contributed to mutagenic and AhR-mediated activities while inhibition of GJIC and estrogenic and TTR-binding activities were exclusively observed in the polar fractions. Known mutagens in polar fractions included nitro- and dinitro-PAHs, azaarenes, and keto-PAHs, while parent and monomethylated PAHs such as benzo[a]pyrene and benzofluoranthenes were identified in nonpolar fractions. Additionally, for one sample, high AhR-mediated activities were determined in one fraction characterized by PCDD/Fs, PCBs, and PCNs. Estrone, 17β-estradiol, 9H-benz[de]anthracen-7-one, and 4-nonylphenol were identified as possible estrogenic and TTR-binding compounds. Thus, not only nonpolar compounds such as PAHs, PCBs, and PCDD/Fs but also the less characterized and investigated more polar substances should be considered as potent mutagenic, estrogenic, AhR-inducing, TTR-binding, and GJIC-inhibiting components for future studies.     

Dimensions of career indecision.

[Correction Notice: An erratum for this article was reported in Vol 37(2) of Journal of Counseling Psychology (see record 2008-10626-001). Editorial error resulted in several misstatements. On page 98, second column, in the 11th line of the second paragraph, the word students ought to read studies; on page 101, in the 9th line, the word Behaviors ought to read Barriers. On page 102, in line 5 of the first paragraph, the reference ought to be to the top left panel of Figure 2. The second paragraph ought to begin with the reference to the top right panel of Figure 2. Also on page 102, the sentence that begins on line 5 of the first paragraph was intended to read, as follows: Two of the groups of girls changed significantly in the expected direction: Group 2 (decided-undecided) significantly increased and Group 3 (undecided-decided) significantly decreased over time.] Recent studies have clarified the factor structure of the Career Decision Scale (CDS), thereby permitting the construction of 4 linearly independent scales to measure dimensions of career indecision. The CDS was administered to 465 junior and senior high school students. The study examined whether the CDS total score and the 4 subscales were related to the students' career decision status, grade level, and gender. Data were collected twice, 6 months apart, to study whether changes in decision status were accompanied by changes in the CDS total score and the 4 subscales and whether these changes differed according to gender or grade level. In addition, a subsample was followed for 3 years to examine long-term change. The results demonstrated the utility of using factor-based subscales to create a typology of career indecision. Many significant differences on the various indecision scales were found to be due to gender and to career decision status but not to grade level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computational Evolution of Beta-2-Microglobulin Binding Peptides for Nanopatterned Surface Sensors

The bottom-up design of smart nanodevices largely depends on the accuracy by which each of the inherent nanometric components can be functionally designed with predictive methods. Here, we present a rationally designed, self-assembled nanochip capable of capturing a target protein by means of pre-selected binding sites. The sensing elements comprise computationally evolved peptides, designed to target an arbitrarily selected binding site on the surface of beta-2-Microglobulin (β2m), a globular protein that lacks well-defined pockets. The nanopatterned surface was generated by an atomic force microscopy (AFM)-based, tip force-driven nanolithography technique termed nanografting to construct laterally confined self-assembled nanopatches of single stranded (ss)DNA. These were subsequently associated with an ssDNA–peptide conjugate by means of DNA-directed immobilization, therefore allowing control of the peptide’s spatial orientation. We characterized the sensitivity of such peptide-containing systems against β2m in solution by means of AFM-based differential topographic imaging and surface plasmon resonance (SPR) spectroscopy. Our results show that the confined peptides are capable of specifically capturing β2m from the surface–liquid interface with micromolar affinity, hence providing a viable proof-of-concept for our approach to peptide design.     

Ranitidine bismuth citrate in the treatment of Helicobacter pylori infection and duodenal ulcer

STATEMENT OF PROBLEM: The existence of mandibular lateral translation and the approaches to its measurement and interpretation by using a pantograph are controversial. PURPOSE: This study evaluated the validity of using a pantograph to measure mandibular lateral translation and analyzed human pantographic tracings to determine whether they exhibited mandibular lateral translation. MATERIAL AND METHODS: A pantograph was modified by adding 2 posterior horizontal recording tables and styli at the transverse horizontal axis. Pantographic tracings of 25 human subjects were compared with the corresponding theoretically determined values for tracings that exhibited only rotation with no translation. Differences in the tracings at 2 pantographic recording table locations, relative to the transverse horizontal axis, were also compared. RESULTS: The character of the lateral component of 100 pantographic tracings all differed from the lateral component of theoretically determined values for pure rotation. In 64% of tracings, over 50% of the total mandibular lateral translation occurred by the first 1 mm of forward movement of the nonworking side condyle. In 94% of tracings, more than 50% of the translation had occurred in the first 3 mm of forward movement. For the pantographic system used, the amount of mandibular translation represented in the tracing was not changed by altering the posterior horizontal recording table position in the anterior-posterior direction, relative to the transverse horizontal axis. CONCLUSION: All subjects showed evidence of mandibular lateral translation. New definitions for timing of mandibular lateral translation are proposed. Of the tracings, 64% were classified as exhibiting early translation, 30% as intermediate, and 4% as late mandibular lateral translation.     

Data management for land disposal of liquid sludge

Metrogro is a program for augmenting the soil on privately-owned farms by application of liquid digested sludge. The system has been operated since 1979. In 1982, more than 60 farmers had approx. 2900 acres of crop land treated. The success of the program has been due to the active marketing and service program as well as to financial savings to farmers who may save more than $60 per acre in fertilizer costs. A comprehensive program to monitor the soil, crop, sludge, and groundwater provides large amounts of information. The data base now includes data on the physical and chemical properties of the sludge, soil chemistry, amounts of sludge hauled and applied, and information on more than three hundred wells in the region. These data are organized into seven computer files which can be queried and manipulated using a data management program.     

The development of falling asleep during the first months of life in man (author's transl)

Ten normal infants were studied at 2, 6, 12 and 20 weeks of age. EEG, respiratory rhythm, eye movements and chin EMG were recorded after the evening meal. Recording was continued during the stages of sleep. During the period of falling asleep the periods of REM sleep have been analyzed and compared with the periods of REM sleep occurring after non-REM sleep. REM sleep occurring on falling asleep and that occurring after non-REM sleep differed. Some of the following criteria were different at the earliest time of examination; absence of chin EMG activity, number of apnoeic episodes; other criteria (eye movements, respiration) differed during the first 5 months. The large number of eye movements at 2 and 6 weeks and the high respiratory rate, corresponding to that occurring during waking, could indicate that during REM sleep occurring on falling asleep, one is observing manifestations connected with the waking state.     

"Dimensions of career indecision": Correction to Vondracek, Hostetler, Schulenberg, and Shimizu.

Reports an error in "Dimensions of career indecision" by Fred W. Vondracek, Michelle Hostetler, John E. Schulenberg and Kazuaki Shimizu (Journal of Counseling Psychology, 1990[Jan], Vol 37[1], 98-106). Editorial error resulted in several misstatements. On page 98, second column, in the 11th line of the second paragraph, the word students ought to read studies; on page 101, in the 9th line, the word Behaviors ought to read Barriers. On page 102, in line 5 of the first paragraph, the reference ought to be to the top left panel of Figure 2. The second paragraph ought to begin with the reference to the top right panel of Figure 2. Also on page 102, the sentence that begins on line 5 of the first paragraph was intended to read, as follows: Two of the groups of girls changed significantly in the expected direction: Group 2 (decided-undecided) significantly increased and Group 3 (undecided-decided) significantly decreased over time. (The following abstract of the original article appeared in record 1990-13462-001.) Recent studies have clarified the factor structure of the Career Decision Scale (CDS), thereby permitting the construction of 4 linearly independent scales to measure dimensions of career indecision. The CDS was administered to 465 junior and senior high school students. The study examined whether the CDS total score and the 4 subscales were related to the students' career decision status, grade level, and gender. Data were collected twice, 6 months apart, to study whether changes in decision status were accompanied by changes in the CDS total score and the 4 subscales and whether these changes differed according to gender or grade level. In addition, a subsample was followed for 3 years to examine long-term change. The results demonstrated the utility of using factor-based subscales to create a typology of career indecision. Many significant differences on the various indecision scales were found to be due to gender and to career decision status but not to grade level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)