Juvenile chronic arthritis: a cephalometric analysis of the facial skeleton

A retrospective cross-sectional cephalometric investigation was undertaken to examine the facial form of a group of Finnish children with juvenile chronic arthritis (JCA). Following digitization, the radiographs were divided into three age groups, and according to whether or not 'bird-face' deformity was present. From a total of 67 cases (39 females and 28 males) 19 per cent were judged to be 'affected'. Analyses were carried out and the groups compared using t-tests. The mandible was found to be smaller both in ramal height and body length in the affected sample, with reduction in posterior face height being only partly compensated by increase in bony apposition at the angle producing antegonial notching. There was posterior rotation of the mandible with a reduction in angles S-N-B and S-N-Pog, and an increase in the gonial angle, the angle between the mandibular plane and S-N, maxillary, and occlusal planes. The changes in the maxilla were less marked. Although S-N-A was reduced in all three age groups, it was not significantly so. Maxillary length (ANS-PNS) was significantly smaller in the two younger age groups. In the vertical plane maxillary dimensions were reduced in the two younger age groups. A highly significant increase in the occlusal to maxillary planes angle was observed in all groups. There was, however, no difference in S-N to maxillary planes angle, indicating a more steeply inclined occlusal plane due to subnormally erupted maxillary molars. Although the inter-incisal angle was reduced there was no significant difference in the incisor inclinations in relation to the jaws and despite the posterior rotation of the mandible there was no significant increase in size of overjet or in the frequency of anterior open bite.     

Control-canonical-form method applied to generating systems to improve dynamic stability characteristics

Contents The control-canonical-form (CCF) method is introduced for the purpose of applying it to high-order state-space single-input single or multiple-output (SISO or SIMO) and multiple-input multiple-output (MIMO) linear time-invariant system models to determine closed-loop systems (i.e. design robust controllers) from which enchanced dynamic stability characteristics and overall performance of these systems is achieved. The method has been applied successfully to a SISO 6th-order linearized state-space open-loop model (representing a simplified hydro power system), and to a MIMO 8th-order linearized state-space open-loop model (representing an 87.5 kVA synchronous machine with conventional exciter supplying power to an electric utility system through an interconnection network)

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Anwendung der kanonischen Form der Zustandsrückführung auf Erzeugersysteme zur Verbesserung der dynamischen Stabilitätseigenschaften

Übersicht Die Methode der kanonischen Form wird auf lineare zeitinvariante Systeme höherer Ordnung im Zustandsraum angewendet, die eine oder mehrere Eingangsgrößen bei einer oder mehreren Ausgangsgrößen aufweisen. Damit werden robuste Regler entworfen, welche die dynamische Stabilität und das gesamte Betriebsverhalten verbessern. Die Methode wurde erfolgreich auf ein linearisiertes Modell sechster Ordnung mit einem Eingang und einem Ausgang angewendet, das vereinfachend eine Wasserkraftanlage darstellt; außerdem auf ein linearisiertes Zustandsmodell achter Ordnung einer Synchronmaschine 87,5kVA mit konventioneller Erregung, die über ein Verbindungsnetzwerk in das öffentliche Netz einspeist.

     

Overview of health-related quality-of-life measures for pediatric patients: application in the assessment of pharmacotherapeutic and pharmacoeconomic outcomes

Health-related quality of life (HRQOL) is an important dimension in assessing health care. Several methodologic considerations are related to the manner in which these data are obtained in children. Few multidimensional generic measures of quality of life (QOL) have been developed for children and adolescents. Most published research concerns the development of tools to be used in a disease-specific manner for clinical trials. Although several authors point out numerous advantages in assessing HRQOL in clinical practice, several barriers must be overcome for this to occur. In the current era of economic restraint, HRQOL measures must be integrated into pharmaco-economic analyses to assess fully the impact of a drug on health care resources and outcomes.     

Hepatic and pancreatic effects of polyenoylphosphatidylcholine in rats with alloxan-induced diabetes

In neonatally allylestrenol treated animals in adult age a single benzpyrene treatment significantly decreases the female and significantly increases the male rat's sexual activity. Three month old females display the negative sexual behavioral effect of neonatal allylestrenol treatment less than the six month old ones. The benzpyrene treatment in adult age decreases the sexual activity of male rats. The experiments call the attention to the modifying effect of perinatal steroid treatments to similar exposure in adult age.     

Calculi with the greatest number

Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 71–86, May–June, 1995.     

Cost-benefit analysis of power system reliability: two utility casestudies

There is an emerging recognition that utility investments and other decisions that affect electric service reliability should be explicitly evaluated on the basis of their cost and benefit implications. A cost-benefit approach that quantifies the reliability benefits of alternatives in terms of the reduction in costs resulting from unserved energy enables the evaluation of generation and transmission capacity additions on a consistent, economic basis. This approach has been applied to two utility case studies. In a case study for Pacific Gas and Electric Company, it was used to evaluate three options for maintaining reliability in a major load center-two involving local generation, and the third, a new 230 kV transmission connection. In a case study for Duke Power Company, the approach was used to evaluate alternative designs for proposed additions to a transmission station. This paper describes the methodology and presents the two utility studies     

A high-current and high-temperature 6H-SiC thyristor

A 6H-SiC thyristor has been fabricated and characterized. A forward breakover voltage close to 100 V and a pulse switched current density of 5200 A/cm² have been demonstrated. The thyristor is shown to operate under pulse gate triggering for turn-on and turn-off, with a rise time of 43 ns and a fall time of less than 100 ns. The forward breakover voltage is found to decrease by only 4% when the operating temperature is increased from room temperature to 300°C. It is found that anode ohmic contact resistance dominates the device forward drop at high current densities     

Pulsed-current duty cycle dependence of electromigration-inducedstress generation in aluminum conductors

The effect of duty cycle of pulsed dc currents on the critical length-current density product, (jl_c), was measured using the Blech-Kinsbron edge-displacement technique [Thin Solid Films 25, 327 (1975)]. Unencapsulated Al edge-displacement segments mere stressed at various duty cycles and the critical lengths, the so-called “Blech lengths”, were measured. It was found that jl_c increased with decreasing duty cycle. We measured a factor of 2.6 increase in jl_c for the 25% duty cycle as compared to dc. This duty cycle dependence of Blech length implies that electromigration resistance for an integrated circuit would be increased for small duty cycle operation by increasing the fraction of interconnects which are sub-Blech-length and are not susceptible to EM damage