Speech sound acquisition, coarticulation, and rate effects in a neural network model of speech production.

This article describes a neural network model of speech motor skill acquisition and speech production that explains a wide range of data on variability, motor equivalence, coarticulation, and rate effects. Model parameters are learned during a babbling phase. To explain how infants learn language-specific variability limits, speech sound targets take the form of convex regions, rather than points, in orosensory coordinates. Reducing target size for better accuracy during slower speech leads to differential effects for vowels and consonants, as seen in experiments previously used as evidence for separate control processes for the 2 sound types. Anticipatory coarticulation arises when targets are reduced in size on the basis of context; this generalizes the well-known look-ahead model of coarticulation. Computer simulations verify the model's properties. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polymers containing formamidine groups

Summary Aliphatic polyformamidines have been synthesized by reaction of aliphatic diamines with triethyl orthoformate in presence of catalytic amounts of acetic acid. The reaction has been carried out in DMSO at 180°C. The polymer structure has been confirmed by IR and NMR spectroscopy. For determination of molecular weights ¹H NMR end group signals have been used.     

Measuring the friction coefficient in the case of plastification of metals by elastomers

The friction measuring apparatus according to O. Pawelski, which is based on the strip drawing experiment, is used to determine friction coefficients in plastic shaping of metals. By implementing elastomer inlays into the drawing cheeks the same principle has been applied to the contact between metals and elastomeric media. The plastification of metal by the extremely shear-weak elastomer is possible, because it is completely constrained with metal, so that a sufficiently high hydrostatic pressure in the inlay is generated. Elementary theory in combination with FEM showed that the friction coefficient, calculated using only the global static equilibrium of forces, is in very good approximation with simply the mixture of the friction coefficient between metal strip and elastomer and the friction coefficient between metal strip and drawing cheek weighted with the corresponding contact areas. Drawing experiments with aluminium 99.5 or steel St 37 and polyurethane or soft rubber were carried out. The important influence of lubrication and roughness of the metal strip on the friction coefficient was investigated.     

Scoring prevalence and severity in gonarthritis: the suitability of the Kellgren & Lawrence scale

OBJECTIVES: Infection with the high-risk strain of human papillomaviruses (HPVs) and the inactivation of the tumor suppressor gene p53 through mutation are important factors in cervical carcinogenesis. To know whether such events would occur in cervical carcinomas of Indians, 43 tumors (consisting of 36 of stage III B and 6 of stage II B) were screened for p53 and p16 gene mutations. METHODS: PCR followed by single-strand conformation polymorphism (SSCP) analysis were used to detect mutations in p53 and p16 genes and PCR for the presence of human papillomavirus genome. HPV status was ascertained by PCR amplification of parts of E6 and E7 genes using primers pU-1M and pU-2R and typing was carried out by restriction analysis. RESULTS: Of the 43 samples analyzed, 4 samples (9%) showed mobility shifts for p53 mutations; PCR products of the p16 gene did not show band shifts in SSCP analysis. HPV DNA was detected in 70% of the 43 samples analyzed: HPV 16 in 23 cases (53%), HPV 18 in 4 cases (13.3%), and HPV 33 in 1 case (3.3%). Two amplified HPV DNAs that were difficult to type with various restriction enzymes were cloned and the amplified regions were sequenced. One of these was 93% close to HPV 35 and the other was 80% close to HPV 58. Three samples had both p53 mutations and HPV genome. CONCLUSIONS: Our results indicate that HPV 16 infection was more common than HPV 18, the p53 mutations and HPV infection were not mutually exclusive events in the genesis of carcinoma of uterine cervix among Indian women, and p16 gene may not play a role in Indian cervical carcinomas.     

Low power laser trigger switching of a solid insulated spark gap

The feasibility of reliably triggering solid dielectric insulated spark gaps by low power ( approximately 6 MW) lasers has been demonstrated. Breakdown of 10-mil Lexan dielectric sheets stressed to 70 kV was initiated by a focused 6 MW, Nd in YAG laser emitting 40 mJ in a pulse 6 ns wide at the half-peak intensity height. Delays achieved were in the tens of ns. Slight increases in laser power or electrical stress should produce shorter delays (<10 ns) and subnanosecond jitter.     

Verhalten des Stahles X 6 CrNi 18 11 unter kombinierter Kriech- und Wechselbeanspruchung bei 823 K

Experimentelle Untersuchung des Kriech- und Wechseldehnverhaltens des austenitischen Stahles X 6 CrNi 18 11 (Werkstoffnummer 1.4948) bei Beanspruchung durch Kriechen und Ermüden. Auswertung der Ergebnisse unter Anwendung der linearen Schadensregel. Vergleich mit Auslegungskriterien nach dem ASME BPVC.     

Monohydroperoxides of linoleic acid in endoplasmic lipids of rats exposed to tetrachloromethane

An accurate method for the quantitative determination of hydroperoxy and hydroxy fatty acids in liver microsomes is presented which involves the use of¹⁸O-labeled internal standards. The method is employed for the determination of hydroperoxides in rat liver microsomes after aerobic incubation with Fe²⁺/ADP and in microsomes from animals exposed to 75 mg tetrachloromethane/kg body weight. The amounts found after artificial microsomal “lipid peroxidation” are almost two orders of magnitude larger than those in microsomes from tetrachloromethaneexposed animals.