Practical guidelines for the assessment and treatment of selective mutism

OBJECTIVE: To provide practical guidelines for the assessment and treatment of children with selective mutism, in light of the recent hypothesis that selective mutism might be best conceptualized as a childhood anxiety disorder. METHOD: An extensive literature review was completed on the phenomenology, evaluation, and treatment of children with selective mutism. Additional recommendations were based on clinical experience from the authors' selective mutism clinic. RESULTS: No systematic studies of the phenomenology of children with selective mutism were found. Reports described diverse and primarily noncontrolled treatment approaches with minimal follow-up information. Assessment and treatment options for selective mutism are presented, based on new hypotheses that focus on the anxiety component of this disorder. Ongoing research suggests a role for behavior modification and pharmacotherapy similar to the approaches used for adults with social phobia. CONCLUSION: Selectively mute children deserve a comprehensive evaluation to identify primary and comorbid problems that might require treatment. A school-based multidisciplinary individualized treatment plan is recommended, involving the combined effort of teachers, clinicians, and parents with home- and clinic-based interventions (individual and family psychotherapy, pharmacotherapy) as required.     

Kurzschlußvorgänge in mehrfach gespeisten,vermaschten Netzen

Zusammenfassung Die Darstellung des Kurzschlusses erfolgte durch Überlagerung der Spannung am Kurzschlußort mit einer Überlagerungsspannung, die ihrerseits wieder in einheitlicher, für die Zeiten vor und nach dem Kurzschlußeintritt geltender Form durch ein Fourier-Integral dargestellt wurde. Aus diesem Überlagerungsspannungsintegral wurden die Überlagerungsstromintegrale abgeleitet unter Verwendung der Stromgleichungen für die einzelnen Teile der untersuchten Anordnungen bzw. der entsprechenden Ersatzwiderstände, deren Aufbau aus den Ersatzwiderständen der Schaltelemente der Anordnungen in allgemeiner Form behandelt wurde. Die Auswertung der Stromintegrale wurde sodann ebenfalls in allgemeiner Form vorgenommen, wobei ein Näherungsverfahren zu grundsätzlicher Anwendung kam, das eine erhebliche Vereinfachung der Rechnung mit sich brachte, ohne daß praktisch eine Einbuße an Genauigkeit auftrat.Zur Erläuterung der gewonnenen allgemeinen Rechenvorschriften wurden einige typische Beispiele behandelt, deren Ergebnisse als Charakteristikum der beim Kurzschluß in vermaschten, mehrfach gespeisten Netzen auftretenden Ausgleichsvorgängen die Tatsache erkennen lassen, daß der Ausgleichsstrom aus mehreren Wechselstromund Gleichstromgliedern besteht, die verschiedene Zeitkonstanten besitzen und sich auf die einzelnen Teile der Anordnung in verschiedener Weise vcrteilen. Im besonderen ergibt sich, daß die Zahl der Wechselstromglieder gleich der Zahl der nicht mehr zusammenfaßbaren Generatoren, und die Zahl der Gleichstromglieder gleich der Zahl der vom Kurzschlußort ausgehenden Stromwege mit verschiedenem Verhältnis von Selbstinduktion zu ohmschem Widerstand plus der Zahl der nicht mehr zusammenfaßbaren Kapazitäten ist. Ferner zeigt sich, daß sich die Stromglieder nicht notwendigerweise sämtlich addieren müssen, sondern daß sie auch teilweise in Opposition stehen können, so daß an manchen Stellen der Fall eintreten kann, daß der Gesamt-Wechselstromanteil oder -Gleichstromanteil anfänglich nur wenig abnimmt, konstant bleibt oder sogar anschwillt.Bemerkenswert ist ferner das Ergebnis, daß beim zweipoligen Kurzschluß im allgemeinen die gesunde Phase nur am Kurzschlußort frei von Überlagerungsströmen ist, während in den übrigen Teilen der Anordnungen auch in dieser Phase ein Überlagerungsstrom fließt, der jedoch ohne Stoßerscheinung von Null auf seinen Endwert anwächst.Dissertation des Verfassers, T. H. Berlin, Fakultät für Maschinenwesen.     

Spannungsanisotropie und Struktur von TiN-Schichten

Stress anisotropy and structure of TiN thin films In many sputtering processes the substrate is rotated or periodically moved with respect to the target in order to obtain a homogeneous film deposition. In that case anisotropic conditions of film growth exist which lead to anisotropic mechanical stresses. The stress anisotropy depends on the carrier velocity and can be attributed to the film structure. The stress measurements, therefore, will be related to measurements of composition by SNMS, to determination of stoichiometry by ellipsometry and to investigations of structure by X-ray diffraction.     

Rational design of Rhizopus oryzae lipase with modified stereoselectivity toward triradylglycerols

The binding site of sn-1(3)-regioselective Rhizopus oryzae lipase (ROL) has been engineered to change the stereoselectivity of hydrolysis of triacylglycerol substrates and analogs. Two types of prochiral triradylglycerols were considered: 'flexible' substrates with ether, benzylether or ester groups, and 'rigid' substrates with amide or phenyl groups, respectively, in the sn-2 position. The molecular basis of sn-1(3) stereoselectivity of ROL was investigated by modeling the interactions between substrates and ROL, and the model was confirmed by experimental determination of the stereoselectivity of wild-type and mutated ROL. For the substrates, the following rules were derived: (i) stereopreference of ROL toward triradylglycerols depends on the substrate structure. Substrates with 'flexible' sn-2 substituents are preferably hydrolyzed at sn-1, 'rigid' substrates at sn-3. (ii) Stereopreference of ROL toward triradylglycerols can be predicted by analyzing the geometry of the substrate docked to ROL: if the torsion angle phiO3-C3 of glycerol is more than 150 degrees, the substrate will preferably be hydrolyzed in sn-1, otherwise in sn-3. For ROL, the following rules were derived: (i) residue 258 affects stereoselectivity by steric interactions with the sn-2 substituent rather than polar interactions. To a lower extent, stereoselectivity is influenced by mutations further apart (L254) from residue 258. (ii) With 'rigid' substrates, increasing the size of the binding site (mutations L258A and L258S) shifts stereoselectivity of hydrolysis toward sn-1, decreasing its size (L258F and L258F/L254F) toward sn-3.      

Problem of catalyst ageing during the hot-wire chemical vapour deposition of thin silicon films

The filament in a hot-wire chemical vapour deposition (HWCVD) reactor is an important component. When tantalum (Ta) filaments are used for the deposition of thin silicon films, strong degradation takes place: there is a large amount of silicon not only at the surface but also in the bulk of the tantalum catalyst. Ta-Si phases form on the filament surface and in the bulk, which can lead to a porous structure of the catalyst filament. Filament contamination (silicide formation and thick silicon deposits (TSDs)) is the reason for the changes in filament resistance. It also reduces filament lifetime, which is a serious concern for HWCVD deposition technology. A cleaning procedure for the filament at high-temperatures in a vacuum (about 2000 °C) can neither remove the thick silicon deposits nor fully restore the filament surface properties. In order to decrease the silicon content in the tantalum catalyst and suppress TSD formations on the filament surface, we use radio-frequency alternating current (RF, 13.5 MHz) instead of direct current (DC) to heat the filament. The skin effect of the RF current reduces the formation of TSDs on the surface and silicon diffusion into the filament. We show that it is possible to clean the filament surface of TSDs by means of a high-frequency current. Combined RF + DC filament heating allows us to increase the lifetime of the catalyst (almost twofold) and to improve HWCVD process reproducibility without any deterioration in the quality of the deposited film.     

beta-Endorphin and adrenocorticotrophin after incremental exercise and marathon running--female responses

Investigations of exercise-induced increases in beta-endorphin, adrenocorticotropic hormone (ACTH) and cortisol concentration have been carried out mainly in men. Data concerning the female reaction are sparse and less clear. In a comparison between incremental exercise and marathon running 14 experienced female marathon runners volunteered to run to exhaustion according to an incremental treadmill protocol. They ran a marathon 4 weeks later. Blood was analysed for beta-endorphin, ACTH and cortisol concentration immediately prior to the laboratory treadmill test, 3, 30 and 60 min later, as well as prior to the marathon, after 60 min and 120 min of running and 3, 30 min, and 24 h after completion of the run. At each blood collection, lactate concentration, heart frequency and perceived exertion were determined. The mean marathon running time was 3.22 h. Baseline concentrations for beta-endorphin of 22 pmol.l-1 before the marathon and 19 pmol.l-1 before the treadmill exercise increased 1.4-fold 30 min after the marathon and 1.9-fold after the treadmill exercise; for ACTH the baseline of 4.7 and 4.0 pmol.l-1 was increased by 8.3- and 10.3-fold, respectively. Cortisol concentration rose exponentially from a baseline 17 micrograms.dl-1 and peaked at 2.2-fold 30 min after the run, when the maximal concentration also had been reached after the treadmill test, increasing 1.3-fold from a baseline of 21 micrograms.dl-1. The maximal values for cortisol concentration after both exercises differed from each other, while the maxima of ACTH and beta-endorphin concentrations were similar. The ACTH and beta-endorphin concentration declined more slowly during the recovery after the marathon than after the treadmill. Cortisol concentration was below baseline 24 h later. In comparison with men studied earlier, female marathon runners showed higher baseline concentrations and lesser increases in beta-endorphin and lower baseline concentrations and larger increases in ACTH concentration after both types of exercise. The delayed decrease in concentration of the hormones after the marathon was similar in male and female runners.     

Comparison of measured and calculated dose rates for the Castor HAW 20/28 CG

In January 2003 neutron and gamma dose rate measurements at a CASTOR HAW 20/28 CG were performed by the Bundesamt für Strahlenschutz at Gorleben. First, commercial dose rate measurement devices were used, then spectral measurements with a Bonner sphere system were made to verify the results. Axial and circumferential dose rate profiles were measured near the cask surface and spectral measurements were performed for some locations. A shielding analysis of the cask was performed with the MCNP Monte Carlo Code with ENDF/B-VI cross section libraries. The cask was modelled 'as built', i.e. with its real inventory, dimensions and material densities and with the same configuration and position as in the storage facility. The average C/E-ratios are 1.3 for neutron dose rates and 1.4 for gamma dose rates. Both the measured and calculated dose rates show the same qualitative trends in the axial and circumferential direction. The spectral measurements show a variation in the spectra across the cask surface. This correlates with the variation found in the C/E-ratios. At cask midheight good agreement between the Bonner sphere system and the commercial device (LB 6411) is found with a 7% lower derived H*(10) dose rate from the Bonner sphere system.