1000 resultados para strain theory of suicide


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Quarks were introduced 50 years ago opening the road towards our understanding of the elementary constituents of matter and their fundamental interactions. Since then, a spectacular progress has been made with important discoveries that led to the establishment of the Standard Theory that describes accurately the basic constituents of the observable matter, namely quarks and leptons, interacting with the exchange of three fundamental forces, the weak, electromagnetic and strong force. Particle physics is now entering a new era driven by the quest of understanding of the composition of our Universe such as the unobservable (dark) matter, the hierarchy of masses and forces, the unification of all fundamental interactions with gravity in a consistent quantum framework, and several other important questions. A candidate theory providing answers to many of these questions is string theory that replaces the notion of point particles by extended objects, such as closed and open strings. In this short note, I will give a brief overview of string unification, describe in particular how quarks and leptons can emerge and discuss what are possible predictions for particle physics and cosmology that could test these ideas.

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Quarks were introduced 50 years ago opening the road towards our understanding of the elementary constituents of matter and their fundamental interactions. Since then, a spectacular progress has been made with important discoveries that led to the establishment of the Standard Theory that describes accurately the basic constituents of the observable matter, namely quarks and leptons, interacting with the exchange of three fundamental forces, the weak, electromagnetic and strong force. Particle physics is now entering a new era driven by the quest of understanding of the composition of our Universe such as the unobservable (dark) matter, the hierarchy of masses and forces, the unification of all fundamental interactions with gravity in a consistent quantum framework, and several other important questions. A candidate theory providing answers to many of these questions is string theory that replaces the notion of point particles by extended objects, such as closed and open strings. In this short note, I will give a brief overview of string unification, describe in particular how quarks and leptons can emerge and discuss what are possible predictions for particle physics and cosmology that could test these ideas.

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In this article, we present a new microscopic theoretical approach to the description of spin crossover in molecular crystals. The spin crossover crystals under consideration are composed of molecular fragments formed by the spin-crossover metal ion and its nearest ligand surrounding and exhibiting well defined localized (molecular) vibrations. As distinguished from the previous models of this phenomenon, the developed approach takes into account the interaction of spin-crossover ions not only with the phonons but also a strong coupling of the electronic shells with molecular modes. This leads to an effective coupling of the local modes with phonons which is shown to be responsible for the cooperative spin transition accompanied by the structural reorganization. The transition is characterized by the two order parameters representing the mean values of the products of electronic diagonal matrices and the coordinates of the local modes for the high- and low-spin states of the spin crossover complex. Finally, we demonstrate that the approach provides a reasonable explanation of the observed spin transition in the [Fe(ptz)6](BF4)2 crystal. The theory well reproduces the observed abrupt low-spin → high-spin transition and the temperature dependence of the high-spin fraction in a wide temperature range as well as the pronounced hysteresis loop. At the same time within the limiting approximations adopted in the developed model, the evaluated high-spin fraction vs. T shows that the cooperative spin-lattice transition proves to be incomplete in the sense that the high-spin fraction does not reach its maximum value at high temperature.

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Spurred by the consumer market, companies increasingly deploy smartphones or tablet computers in their operations. However, unlike private users, companies typically struggle to cover their needs with existing applications, and therefore expand mobile software platforms through customized applications from multiple software vendors. Companies thereby combine the concepts of multi-sourcing and software platform ecosystems in a novel platform-based multi-sourcing setting. This implies, however, the clash of two different approaches towards the coordination of the underlying one-to-many inter-organizational relationships. So far, however, little is known about impacts of merging coordination approaches. Relying on convention theory, we addresses this gap by analyzing a platform-based multi-sourcing project between a client and six software vendors, that develop twenty-three custom-made applications on a common platform (Android). In doing so, we aim to understand how unequal coordination approaches merge, and whether and for what reason particular coordination mechanisms, design decisions, or practices disappear, while new ones emerge.

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BACKGROUND Compliance with surgical checklist use remains an obstacle in the context of checklist implementation programs. The theory of planned behaviour was applied to analyse attitudes, perceived behaviour control, and norms as psychological antecedents of individuals' intentions to use the checklist. METHODS A cross-sectional survey study with staff (N = 866) of 10 Swiss hospitals was conducted in German and French. Group mean differences between individuals with and without managerial function were computed. Structural equation modelling and confirmatory factor analysis was applied to investigate the structural relation between attitudes, perceived behaviour control, norms, and intentions. RESULTS Significant mean differences in favour of individuals with managerial function emerged for norms, perceived behavioural control, and intentions, but not for attitudes. Attitudes and perceived behavioural control had a significant direct effect on intentions whereas norms had not. CONCLUSIONS Individuals with managerial function exhibit stronger perceived behavioural control, stronger norms, and stronger intentions. This could be applied in facilitating checklist implementation. The structural model of the theory of planned behaviour remains stable across groups, indicating a valid model to describe antecedents of intentions in the context of surgical checklist implementation.

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The concept of theory of mind (ToM), a hot topic in cognitive psychology for the past twenty-five years, has gained increasing importance in the fields of linguistics and pragmatics. However, even though the relationship between ToM and verbal communication is now recognized, the extent, causality and full implications of this connection remain mostly to be explored. This book presents a comprehensive discussion of the interface between language, communication, and theory of mind, and puts forward an innovative proposal regarding the role of discourse connectives for this interface. The proposed analysis of connectives is tested from the perspective of their acquisition, using empirical methods such as corpus analysis and controlled experiments, thus placing the study of connectives within the emerging framework of experimental pragmatics.

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This is the edited and translated version of the article by Richard Scherhag “Zur Theorie der Hoch- und Tiefdruckgebiete. Die Bedeutung der Divergenz in Druckfeldern” (On the theory of high and low pressure areas: The significance of divergence in pressure areas), which was published in Meteorologische Zeitschrift 51, 129–138.

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The entrepreneurial theory of the firm argues that entrepreneurship, properly understood, is a crucial but neglected element in explaining the nature and boundaries of the firm. By contrast, the theory of the entrepreneurial firm presumably seeks not to understand the nature and boundaries of "the firm" in general but rather to understand a particular type of firm: one that is entrepreneurial. This paper is an attempt to reconcile the two. After briefly delving for the concept of entrepreneurship in the work of Schumpeter, Kirzner, and (especially) Knight, the paper makes the case for the entrepreneurial theory of the firm. In such a theory, the firm exists as the solution to a coordination problem in a world of change and uncertainty, including Knightian or structural uncertainty. Taking a historical or developmental perspective, the paper then examines the changing nature of the entrepreneurial coordination problem over the life-cycle. In this formulation, "the entrepreneurial firm" is a nascent firm or proto-firm facing a problem of coordinating systemic change in economic capabilities. Lacking (by definition) adequate guidance from existing systems of rules of conduct embedded in markets or organizations, the entrepreneurial firm typically relies on a form of organization Max Weber called charismatic authority. In the end, although there is no such thing as a non-entrepreneurial firm, firms that must solve coordination problems in a world of novelty and systemic change ("entrepreneurial firms") are perhaps the purest case of the entrepreneurial theory of the firm.

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Redemption laws give mortgagors the right to redeem their property following default for a statutorily set period of time. This paper develops a theory that explains these laws as a means of protecting landowners against the loss of non-transferable values associated with their land. A longer redemption period reduces the risk that this value will be lost but also increases the likelihood of default. The optimal redemption period balances these effects. Empirical analysis of cross-state data from the early twentieth century suggests that these factors, in combination with political considerations, explain the existence and length of redemption laws.

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Redemption laws give mortgagors the right to redeem their property following default for a statutorily set period of time. This paper develops a theory that explains these laws as a means of protecting landowners against the loss of nontransferable values associated with their land. A longer redemption period reduces the risk that this value will be lost but also increases the likelihood of default. The optimal redemption period balances these effects. Empirical analysis of cross-state data from the early twentieth century suggests that these factors, in combination with political considerations, explain the existence and length of redemption laws.

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Economic models of crime have focused primarily on the goal of deterrence; the goal of incapacitation has received much less attention. This paper adapts the standard deterrence model to incorporate incapacitation. When prison only is used, incapacitation can result in a longer or a shorter optimal prison term compared to the deterrence-only model. It is longer if there is underdeterrence, and shorter if there is overdeterrence. In contrast, when a fine is available and it is not constrained by the offender's wealth, the optimal prison term is zero. Since the fine achieves first-best deterrence, only efficient crimes are committed and hence, there is no gain from incapacitation.

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A feature of many penal codes is that punishments are more severe for repeat offenders, yet economic models have had a hard time providing a theoretical justification for this practice. This paper offers an explanation based on the wage penalty suffered by individuals convicted of crime. While this penalty probably deters some first-timers from committing crimes, it actually hampers deterrence of repeat offenders because of their diminished employments opportunities. We show that in this setting, an escalating penalty scheme is optimal and time consistent.