An inelastic model with indiscernibles

1978 ◽  
Vol 43 (2) ◽  
pp. 331-334 ◽  
Author(s):  
Julia F. Knight
Keyword(s):  
Relation Symbol ◽  
Unary Relation ◽  
Mere Presence ◽  
Carry Over ◽  
Infinite Set

Let L be a countable language including the unary relation symbol U. Let and be L-structures such that is a proper elementary U-extension of ; i.e., , and . Under what conditions will have a proper elementary U-extension? In [2], it was shown that this is not always the case, even if and are countable. However, the examples given are completely artificial, and it still seems that in most cases will have a proper elementary U-extension.Lascar asked whether will necessarily have a proper elementary U-extension whenever it contains an infinite set of indiscernibles over . This paper gives a counterexample for Lascar's question. The example is produced by modifying one of the examples in [2], using an idea of Marcus [5].Models containing an infinite set of indiscernibles can often be “stretched” to produce larger models that share some desired nonelementary property with the original [1], [6]. However, the mere presence of indiscernibles in a model does not guarantee that it can be used in this way.If the model is not completely determined by the indiscernibles, the nonelementary property may not carry over to larger models. An example of this is given in [3]. The example for Lascar's question is further evidence that models with indiscernibles need not be “elastic”.

scholarly journals Completeness of two theories on ordered abelian groups and embedding relations

1980 ◽  
Vol 77 ◽  
pp. 33-39 ◽  
Author(s):  
Yuichi Komori
Keyword(s):  
Binary Relation ◽  
Abelian Groups ◽  
Function Symbol ◽  
Binary Function ◽  
Relation Symbol ◽  
Unary Function ◽  
First Order ◽  
Order Language ◽  
Unary Relation ◽  
Binary Relation Symbol

The first order language ℒ that we consider has two nullary function symbols 0, 1, a unary function symbol –, a binary function symbol +, a unary relation symbol 0 <, and the binary relation symbol = (equality). Let ℒ′ be the language obtained from ℒ, by adding, for each integer n > 0, the unary relation symbol n| (read “n divides”).

scholarly journals A uniform method for proving lower bounds on the computational complexity of logical theories

2001 ◽  
Author(s):  
Kevin J. Compton ◽  
C. Ward Henson
Keyword(s):  
Computational Complexity ◽  
Lower Bounds ◽  
Uniform Method ◽  
Order Logic ◽  
First Order Logic ◽  
Finite Model ◽  
Relation Symbol ◽  
Unary Relation ◽  
Second Order Logic ◽  
Monadic Second Order Logic

In this chapter we present a method for obtaining lower bounds on the computational complexity of logical theories, and give several illustrations of its use. This method is an extension of widely used procedures for proving the recursive undecidability of logical theories. (See Rabin [1965] and Eršov et al. [1965].) One important aspect of this method is that it is based on a family of inseparability results for certain logical problems, closely related to the well-known inseparability result of Trakhtenbrot (as refined by Vaught), that no recursive set separates the logically valid sentences from those which are false in some finite model, as long as the underlying language has at least one non-unary relation symbol. By using these inseparability results as a foundation, we are able to obtain hereditary lower bounds, i.e., bounds which apply uniformly to all subtheories of the theory. The second important aspect of this method is that we use interpretations to transfer lower bounds from one theory to another. By doing this we eliminate the need to code machine computations into the models of the theory being studied. (The coding of computations is done once and for all in proving the inseparability results.) By using interpretations, attention is centred on much simpler definability considerations, viz., what kinds of binary relations on large finite sets can be defined using short formulas in models of the theory. This is conceptually much simpler than other approaches that have been proposed for obtaining lower bounds, such as the method of bounded concatenations of Fleischmann et al. [1977]. We will deal primarily with theories in first-order logic and monadic second-order logic.

Some characterization theorems for infinitary universal Horn logic without equality

1996 ◽  
Vol 61 (4) ◽  
pp. 1242-1260 ◽  
Author(s):  
Pilar Dellunde ◽  
Ramon Jansana
Keyword(s):  
Algebraic Logic ◽  
Point Of View ◽  
Abstract Algebraic Logic ◽  
Relation Symbol ◽  
Horn Logic ◽  
First Order ◽  
Order Language ◽  
Unary Relation ◽  
Theoretic Point ◽  
Horn Fragment

In this paper we mainly study preservation theorems for two fragments of the infinitary languages Lκκ, with κ regular, without the equality symbol: the universal Horn fragment and the universal strict Horn fragment. In particular, when κ is ω, we obtain the corresponding theorems for the first-order case.The universal Horn fragment of first-order logic (with equality) has been extensively studied; for references see [10], [7] and [8]. But the universal Horn fragment without equality, used frequently in logic programming, has received much less attention from the model theoretic point of view. At least to our knowledge, the problem of obtaining preservation results for it has not been studied before by model theorists. In spite of this, in the field of abstract algebraic logic we find a theorem which, properly translated, is a preservation result for the strict universal Horn fragment of infinitary languages without equality which, apart from function symbols, have only a unary relation symbol. This theorem is due to J. Czelakowski; see [5], Theorem 6.1, and [6], Theorem 5.1. A. Torrens [12] also has an unpublished result dealing with matrices of sequent calculi which, properly translated, is a preservation result for the strict universal Horn fragment of a first-order language. And in [2] of W. J. Blok and D. Pigozzi we find Corollary 6.3 which properly translated corresponds to our Corollary 19, but for the case of a first-order language that apart from its function symbols has only one κ-ary relation symbol, and for strict universal Horn sentences. The study of these results is the basis for the present work. In the last part of the paper, Section 4, we will make these connections clear and obtain some of these results from our theorems. In this way we hope to make clear two things: (1) The field of abstract algebraic logic can be seen, in part, as a disguised study of universal Horn logic without equality and so has an added interest. (2) A general study of universal Horn logic without equality from a model theoretic point of view can be of help in the field of abstract algebraic logic.

Minimizing Carry-Over Effects After Treatment Failure and Maximizing Therapeutic Outcome

2014 ◽  
Vol 222 (3) ◽  
pp. 171-178 ◽  
Author(s):  
Mareile Hofmann ◽  
Nathalie Wrobel ◽  
Simon Kessner ◽  
Ulrike Bingel
Keyword(s):  
Treatment Failure ◽  
Human Subjects ◽  
Subsequent Treatment ◽  
Clinical Samples ◽  
Administration Route ◽  
Healthy Human ◽  
Negative Experiences ◽  
Analgesic Treatment ◽  
Balanced Design ◽  
Carry Over

According to experimental and clinical evidence, the experiences of previous treatments are carried over to different therapeutic approaches and impair the outcome of subsequent treatments. In this behavioral pilot study we used a change in administration route to investigate whether the effect of prior treatment experience on a subsequent treatment depends on the similarity of both treatments. We experimentally induced positive or negative experiences with a topical analgesic treatment in two groups of healthy human subjects. Subsequently, we compared responses to a second, unrelated and systemic analgesic treatment between both the positive and negative group. We found that there was no difference in the analgesic response to the second treatment between the two groups. Our data indicate that a change in administration route might reduce the influence of treatment history and therefore be a way to reduce negative carry-over effects after treatment failure. Future studies will have to validate these findings in a fully balanced design including larger, clinical samples.

Does CBT for Psychosis Have an Impact on Delusions by Improving Reasoning Biases and Negative Self-Schemas?

2018 ◽  
Vol 226 (3) ◽  
pp. 152-163 ◽  
Author(s):  
Stephanie Mehl ◽  
Björn Schlier ◽  
Tania M. Lincoln
Keyword(s):  
Behavioral Therapy ◽  
Theoretical Models ◽  
Self Esteem ◽  
Secondary Outcome ◽  
Intervention Effect ◽  
Produce Change ◽  
Attribution Biases ◽  
Carry Over ◽  
Implicit And Explicit ◽  
Reasoning Biases

Abstract. Cognitive-behavioral therapy for psychosis (CBTp) builds on theoretical models that postulate reasoning biases and negative self-schemas to be involved in the formation and maintenance of delusions. However, it is unclear whether CBTp induces change in delusions by improving these proposed causal mechanisms. This study reports on a mediation analysis of a CBTp effectiveness trial in which delusions were a secondary outcome. Patients with psychosis were randomized to individualized CBTp (n = 36) or a waiting list condition (WL; n = 34). Reasoning biases (jumping to conclusions, theory of mind, attribution biases) and self-schemas (implicit and explicit self-esteem; self-schemas related to different domains) were assessed pre- and post-therapy/WL. The results reveal an intervention effect on two of four measures of delusions and on implicit self-esteem. Nevertheless, the intervention effect on delusions was not mediated by implicit self-esteem. Changes in explicit self-schemas and reasoning biases did also not mediate the intervention effects on delusions. More focused interventions may be required to produce change in reasoning and self-schemas that have the potential to carry over to delusions.

Investigation on the control of multiphase flow behavior in a continuous casting tundish during ladle change

2020 ◽  
Vol 117 (6) ◽  
pp. 619
Author(s):  
Rui Xu ◽  
Haitao Ling ◽  
Haijun Wang ◽  
Lizhong Chang ◽  
Shengtao Qiu
Keyword(s):  
Multiphase Flow ◽  
Flow Behavior ◽  
Rolled Strip ◽  
Impact Zone ◽  
Steel Cleanliness ◽  
Carry Over ◽  
Slag Carry Over ◽  
Hot Rolled ◽  
Turbulence Inhibitor ◽  
The Impact

The transient multiphase flow behavior in a single-strand tundish during ladle change was studied using physical modeling. The water and silicon oil were employed to simulate the liquid steel and slag. The effect of the turbulence inhibitor on the slag entrainment and the steel exposure during ladle change were evaluated and discussed. The effect of the slag carry-over on the water-oil-air flow was also analyzed. For the original tundish, the top oil phase in the impact zone was continuously dragged into the tundish bath and opened during ladle change, forming an emulsification phenomenon. By decreasing the liquid velocities in the upper part of the impact zone, the turbulence inhibitor decreased considerably the amount of entrained slag and the steel exposure during ladle change, thereby eliminating the emulsification phenomenon. Furthermore, the use of the TI-2 effectively lowered the effect of the slag carry-over on the steel cleanliness by controlling the movement of slag droplets. The results from industrial trials indicated that the application of the TI-2 reduced considerably the number of linear inclusions caused by ladle change in hot-rolled strip coils.

Effects of insecticides on adults and eggs of Drosophila suzukii (Diptera, Drosophilidae)

2017 ◽  
Vol 43 (2) ◽  
pp. 208 ◽  
Author(s):  
Daniele Cristine Hoffmann Schlesener ◽  
Jutiane Wollmann ◽  
Juliano De Bastos Pazini ◽  
Anderson Dionei Grützmacher ◽  
Flávio Roberto Mello Garcia
Keyword(s):  
North America ◽  
South America ◽  
Chemical Control ◽  
Stone Fruits ◽  
Drosophila Suzukii ◽  
Ovicidal Effect ◽  
Mere Presence ◽  
South Of Brazil ◽  
Different Cultures ◽  
First Time

Drosophila suzukii (Diptera, Drosophilidae) is an exotic species, endemic to Asia and currently a pest to small and stone fruits in several countries of North America and Europe. It was detected in 2013 for the first time in South America, in the south of Brazil. Unlike most drosophilids, this species deserves special attention, because the females are capable of oviposit inside healthy fruits, rendering their sale and export prohibited. Despite the confirmed existence of this species in different states of Brazil, this insect is yet been to be given the pest status. Nevertheless, the mere presence of this species is enough to cause concern to producers of small fruits and to justify further investigation for it’s control, especially chemical control for a possible change in status. Therefore, the goal of this work was to evaluate, in laboratory, mortality of D. suzukii adults and ovicidal effect when exposed to different insecticides registered for species of the Tephritidae and Agromyzidae families in different cultures. The insecticides deltamethrin, dimethoate, spinosad, fenitrothion, phosmet, malathion, methidathion, and zeta-cypermethrin resulted in mortality to 100 % of the subjects three days after the treatment (DAT). Regarding the effects over eggs, it was  established that the insecticides fenitrothion, malathion, and methidathion deemed 100 % of the eggs not viable, followed by phosmet and diflubenzuron, which also caused elevated reduction in the eclosion of larvae two DAT.

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