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Arieli O.,The Academic College of Tel-Aviv-Yaffo
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

In this paper we propose a new presentation of logic-based argumentation theory through Gentzen-style sequent calculi. We show that arguments may be represented by Gentzen-type sequents and that attacks between arguments may be represented by sequent elimination rules. This framework is logic-independent, i.e., it may be based on arbitrary languages and consequence relations. Moreover, the usual conditions of minimality and consistency of support sets are relaxed, allowing for a more flexible way of expressing arguments, which also simplifies their identification. This generic representation implies that argumentation theory may benefit from incorporating techniques of proof theory and that different non-classical formalisms may be used for backing up intended argumentation semantics. © 2013 Springer-Verlag. Source

Ben-Amram A.M.,The Academic College of Tel-Aviv-Yaffo
Logical Methods in Computer Science

Size-Change Termination (SCT) is a method of proving program termination based on the impossibility of infinite descent. To this end we use a program abstraction in which transitions are described by monotonicity con-straints over (abstract) variables. When only constraints of the form x > y' and x ≥ y' are allowed, we have size-change graphs. In the last decade, both theory and practice have evolved significantly in this restricted framework. The crucial underlying assumption of most of the past work is that the domain of the variables is well-founded. In a recent paper I showed how to extend and adapt some theory from the domain of size-change graphs to general monotonicity constraints, thus complementing previous work, but remaining in the realm of well-founded domains. However, monotonicity constraints are, interestingly, capable of proving termination also in the integer domain, which is not well-founded. The purpose of this paper is to explore the application of monotonicity constraints in this domain. We lay the necessary theoretical foundation, and present precise decision procedures for termination; finally, we provide a procedure to construct explicit global ranking functions from monotonicity constraints in singlyexponential time, and of optimal worst-case size and dimension (ordinal). © A. M. Ben-Amram. Source

Einat H.,The Academic College of Tel-Aviv-Yaffo
Harvard Review of Psychiatry

There is a well-known deficiency in valid animalmodels for bipolar disorder. Developing the single idealmodel for the disorder-one that will represent its full scope-will probably not be possible until we have a much better understanding of the underlying pathology. Yet, intermediatemodels, even with partial validity, are critical in order to advance our knowledge and put us into position to develop even better models. The present article discusses the various efforts under way to develop the best models based on our current level of understanding. These efforts include (1) identifying new tests, (2) developing models based on the endophenotypes approach, (3) identifying the best rodent strains, (4) identifying the most appropriate species, (5) segregating susceptible versus resilient animals, and (6) segregating animals that respond or do not respond to treatment. It is suggested that a combined approach that includes these directions and others can result in better models with higher validity that will offer significant help in advancing research on bipolar disorder and developing new and better treatments. © 2014 President and Fellows of Harvard College. Source

Ben-Amram A.M.,The Academic College of Tel-Aviv-Yaffo | Genaim S.,Complutense University of Madrid
Journal of the ACM

In this article, we study the complexity of the problems: given a loop, described by linear constraints over a finite set of variables, is there a linear or lexicographical-linear ranking function for this loop? While existence of such functions implies termination, these problems are not equivalent to termination. When the variables range over the rationals (or reals), it is known that both problems are PTIME decidable. However, when they range over the integers, whether for single-path or multipath loops, the complexity has not yet been determined. We show that both problems are coNP-complete. However, we point out some special cases of importance of PTIME complexity. We also present complete algorithms for synthesizing linear and lexicographical-linear ranking functions, both for the general case and the special PTIME cases. Moreover, in the rational setting, our algorithm for synthesizing lexicographical-linear ranking functions extends existing ones, because our definition for such functions is more general, yet it has PTIME complexity. © 2014 ACM 0004-5411/2014/07-ART26 $15.00. Source

Braunstein-Bercovitz H.,The Academic College of Tel-Aviv-Yaffo
International Journal of Stress Management

The purpose of the current study was to examine a theoretically-based multidimensional model, delineating the nature of the associations between perceived gain of three types of organizational resources and burnout, through the mediation of various dimensions of the work-family conflict (WFC). A sample of 179 mothers of young children, holding demanding careers (hospital nurses) completed several questionnaires. Consistent with the Conservation of Resources theory, structural equation modeling analysis (X2 = 9.24, df = 5, NFI = .93, CFI= .94, TLI = .90, and SRMR = .066) indicated that personal-empowerment (e.g., enhanced self-esteem and a sense of mastery and autonomy) and a supportive work-family culture at the workplace are negatively associated with burnout (β = .32, -.17). The relationship between personalempowerment and burnout was fully mediated by the strain-based source of both work interferes with family and family interferes with work dimensions of the conflict (β = -.18, -.15). These results imply that personal-empowerment may augment resiliency and general resistance to stressors, as it attenuates strain spillover from the work to the family domains, as well as from the family to the work domains. The relationship between a supportive work-family culture and burnout was fully mediated by the work interferes with family dimension (both strain- and time-based sources). However, reduced workload (in terms of sufficient time and space) was excluded from the final model, as it did not contribute to reduced WFC and burnout, above the contribution of the other resourcetypes. Implications for career planning and organizational change processes are discussed. © 2013 American Psychological Association. Source

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