Representation theorems using DOS languages

It is demonstrated that every context-free language is a homomorphic image of the intersection of two DOS languages and that every recursively enumerable language is the homomorphic image of the intersection of three DOS languages. It is also proved that by increasing the number of components in the intersections of DOS languages one gets an infinite hierarchy of classes of languages within the class of context-sensitive languages.     

Educating patients about the benefits and drawbacks of hormone replacement therapy

Transthoracic Doppler echocardiography was used to evaluate the technique of measuring and normal patterns of pulmonary venous flow in fourteen normal dogs. Polyphasic pulmonary venous flow profiles were obtained in all dogs, consisting of one (S) or two (SE and SL) systolic forward flow waves, one early diastolic forward flow wave (D), one reverse flow wave (R) related to atrial contraction, and one reverse flow wave (R2) observed after cessation of systolic flow. Pulmonary venous flow was laminar in 9 dogs (65%). Maximal flow velocity during systole (0.39 +/- 0.14 m/sec) was significantly lower (P < 0.01) than in early diastole (0.56 +/- 0.14 m/sec). During late diastole peak flow velocity was 0.20 +/- 0.08 m/sec and maximum R2 velocity was 0.17 +/- 0.05 m/sec. Duration of mitral A-wave was significantly greater (P < 0.05) than R-wave duration in all dogs (0.075 +/- 0.010 vs 0.058 +/- 0.012 sec). These results can be used for comparison with patterns found in disease states.     

Recording the use of memory in right-boundary grammars and push-down automata

Summary Within the framework of coordinated pair systems a push-down automatonA is formalized as an ordered pair (G ₁,G ₂) of grammars, whereG ₁ is a right-linear grammar modelling the finite state control ofA and the reading of the input ofA, and G₂ is a right-boundary grammar modelling the push-down store ofA. In this paper we present a systematic investigation into the use of memory of right-boundary grammars. Various methods of recording the use of memory are introduced. The results presented concern regularity properties of each of the methods and the interrelationships of the records obtained by different methods. Finally the translation of these results to the level of push-down automata (coordinated pair systems) is discussed.     

An epidemiological study of diagnostic and therapeutic strategies in office practice patients with subacute or chronic pain in the thoracic or low back. Comparison of practices in primary care and rheumatology settings

Mucin was purified by the gel filtration method on columns with high porous molecular sives in buffers with SDS and proteinase inhibitors. The addition of proteinase inhibitors distinctly inhibited proteolytic activity. It was found that the obtained mucin, after disulphide-bound reduction, is dissociated to mucin subunits and N-glycosylated glycoprotein of molecular weight about 75 kDa. This protein has carbohydrate and amino acid composition different from high molecular fraction. The 75 kDa protein is strongly associated with high molecular mass mucin subunits and can be separated either during electrophoresis or fractionation in buffers with 2-mercaptoethanol.     

EOL languages are not codings of FPOL languages

One of the useful results concerning EOL languages states that a language is an EOL language if and only if it is a cording of OL language. In this paper we retine this result by demonstrating that there exist EOL languages that are not codings of languages that are generated by propagating OL systems with finite axiom sets. This solves Problem 10 from the L Systems Problem Book '75.     

Egotism versus generalization-of-uncontrollability explanations of helplessness: Reply to Snyder and Frankel (1989).

M. L. Snyder and A. Frankel (see record 1990-09504-001) argue that our experiments (M. Kofta and G. S?dek; see record 1989-24900-001) were inadequate for testing the egotism theory of helplessness because they did not directly address the role of threat to self-esteem, the process held responsible for helplessness deficits by this theory. We reply that failure experience—the chief manipulation in these experiments—is critical for arousing threat to self-esteem. Therefore, our findings—that (a) noncontingency, not ego-threatening failure, is specifically responsible for helplessness deficits, and (b) availability of excuse for failure in the test phase augments performance deficits instead of mitigating them—call into question the validity of the egotism explanation of helplessness. We conclude that by and large, our study lends support to the original learned helplessness theory of Seligman and his associates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The investigation of aggregate grain size effect on fracture toughness of ordinary concrete structures

The material under investigation was ordinary conerete of B 20 class, different in the sizes of coarse aggregate and water-cement ratio of the same value w/c=0.55. It was found during the tests that there were two kinds of sample cracking mechanisms. Some samples cracked at the moment of the initiation of slit (when P _Q=P _max); in others the decohesion force P _max exceeded P _Q, which was identified as a minor deflection or relative extremum of the curve. The frequency of the second type of cracking increased with the growing size of coarse aggregate grains. Together with the growth of the grain size, the angle of curve inclination also became smaller. This phenomenon can be explained by the fact that, in the process of decohesion, the aggregate grains are relocated and the system of contact between them changes, so the K _Hc depends on coarse aggregate.