We study the expressive power in the finite of the logic Fixed-Point+Counting, the extension of first-order logic which is obtained through adding both the fixed-point constructor and the ability to count. To this end an isomorphism preserving (`generic') model of computation is introduced whose PTime restriction exactly corresponds to this level of expressive power, while its PSpace restriction corresponds to While+Counting. From this model we obtain a normal form which shows a rather clear separation of the relational vs. the arithmetical (...) side of the algorithms involved. In parallel, we study the relations of Fixed-Point+Counting with the infinitary logics L r ∞ω (∃ ≥ m ) m∈ω and the corresponding pebble games. The main result, however, involves the concept of an arithmetical invariant. By this we mean a functor taking every finite relational structure to an expansion of (an initial segment of) the standard arithmetical structure. In particular its values are linearly ordered structures. We establish the existence of a family of arithmetical invariants (J r ) r≥ 1 with the following properties: $\bullet$ The invariants themselves can be evaluated in polynomial time. $\bullet$ A class of finite relational structures is definable in Fixed-Point+Counting if and only if membership can be decided in polynomial time on the basis of the values of one of the invariants. $\bullet$ The invariant J r classifies all finite relational structures exactly up to equivalence with respect to the logic L r ∞ω (∃ ≥ m ) m∈ω . We also give a characterization of Fixed-Point+Counting in terms of sequences of formulae in the L r ωω (∃ ≥ m ) m∈ω : It corresponds exactly to the polynomial time computable families (φ n ) n∈ω in these logics. Towards a positive assessment of the expressive power of Fixed-Point+Counting, it is shown that the natural extension of fixed-point logic by Lindström quantifiers, which capture all the PTime computable properties of cardinalities of definable predicates, is strictly weaker than what we get here. This implies in particular that every extension of fixed-point logic by means of monadic Lindstrom quantifiers, which stays within PTime, must be strictly contained in Fixed-Point+Counting. (shrink)

This paper puts forward the hypothesis that consciousness might be linked to matter in a way which is more sophisticated than the traditional macroscopic Cartesian hypothesis suggests.Advances in the biophysics of the nervous system, not only on the level of its macroscopic functioning but also on the level of individual ion channels, have made the question of how finely consciousness is tied to matter and its dynamics more important. Quantum mechanics limits the attainable resolution and puts into doubt the idea (...) of an infinitely fine-woven attachment. A recent approach to physics rekindles such a rationalist hope. Endophysics focuses on the global implications of microscopic computer simulations of chemical and biophysical processes. A complete artificial universe can be set up in the computer. It produces non-classical and nonlocal effects inside — on the interface that exists between an internal observer (fluid neuron) and the rest of the world. This interface is finer than any brain property to which the status of the mind-body interface has been attributed hitherto. A new class of experiments becomes possible in the artificial world and, by analogy, in the real world. Magnetic resonance imaging experiments, routinely performed under open-loop conditions, can be repeated under psychophysical (closed-loop) conditions — in search for microscopically induced changes in the perceived and measured structure of the world. (shrink)

SummaryThis article approaches eighteenth-century views on scientific academies by examining Haller's utterances, public and private, especially those occasioned by the founding of the Göttingen Society. It deals in turn with his understanding of the distinctive purpose of academies, with his explanation of the chief ways in which they realized this end, with his thoughts on their broader usefulness, and finally with his various reasons for considering close ties with the state to be essential to their productive and harmonious operations.

Much research has been done on the economic effects of self-employment, environmental conditions for entrepreneurial success, as well as attributes if the person him-/herself fits to this career path. To successfully run a business, however, is contingent on the health of the entrepreneur. In particular, small business owners (being solo self-employed without personnel) face financial uncertainties, a high workload, long working hours, and are often unable to call in sick. This study aimed at exploring the working situation considering resources (e.g., (...) autonomy), strain (e.g., dependency on contracts with clients) and health and career outcomes of small business owners. This study used a qualitative approach to comprehensively mirror the working situation. Participants who were 29 small business owners from Germany gave permission for recording expert interviews in which they reported, for example, on health complaints, recovery opportunities, obstacles and resources while running their businesses. The interviews emphasize the meaning of active actions and own responsibility for creating working conditions and enabling autonomy. Small business owners yet have to be able to use the autonomy. Besides personal preferences regarding the career path as being pulled into self-employment and not pushed by situational circumstances also marketability and flexibility played a role and explained health and career issues. Our findings underline that the social network is of utmost importance to small business owners and that social support – even or despite of being solo self-employed – is a key to sustaining health and satisfaction. As voluntariness played an essential role for selecting this specific career path those being pulled into self-employment as no other jobs are available should receive particular support through career counseling. One shortcoming of prior research is that the concrete working situation of small business owners and its impact on health and career has not adequately been taken into account. Based on work-related stress models we developed a frame model specific for the situation of small business owners which allows concrete hypotheses for further quantitative research. (shrink)

The paper examines the very beginnings of Bible Mission in Hungary within the Habsburg Empire in the first part of the nineteenth century. It divides the first thirty years into two major epochs: the one before Gottlieb August Wimmer, Lutheran pastor of Felsőlövő (Oberschützen) and agent of the British and Foreign Bible Society (BFBS) and the one characterized by his work until the revolution of 1848. In the paper, I summarize the main obstacles of Bible Mission both political and religious (...) as well as the main achievements and formations of policies and practices that still define Bible Mission of the Bible Societies in all around the world. The work of BFBS in Hungary in this period was also intertwined with the formative period of the Budapest Scottish Mission, a topic that I also touch in the paper. (shrink)

À moins de définir la justice ou le droit de telle manière qu’il existe entre eux un rapport intrinsèque parce qu’on les a déjà conçus comme indiscernables, le rapport entre eux ne peut être que contingent d’un point de vue conceptuel et ontologique. Puisque la justice au sens matériel constitue toujours une conception particulière de la distribution des biens au sens le plus large, la réalisation d’une telle conception est en revanche toujours subordonnée à la technicité du droit qui la (...) concrétise en réglant les comportements sous des conditions non idéales, faisant intervenir sous certaines conditions, entre autres éléments, des actes de violence. Si le droit est de ce point indifférent par rapport à la justice, toute théorie de la justice doit tenir compte des contraintes de sa réalisation juridique. (shrink)