Models of war 1770–1830: the birth of wargames and the trade-off between realism and simplicity

The first sophisticated wargames (military board games) were developed between 1770 and 1830 and are models of military conflict. Designers of these early games experimented fruitfully with different concepts that were formulated in interaction with the external dynamics of the military systems that they tried to represent and the internal dynamics of the design process itself. The designers of early wargames were confronted with a problem that affects all models: the trade-off between realism and simplicity, which in the case of wargames amounts to the trade-off between realism and playability. I try to show how different game concepts were developed as an answer to this problem, and how these seemingly arcane concepts form a relevant topic of investigation in the history of ideas. Moreover, a direct offshoot of this conceptual experimentation between 1770 and 1830 was the ‘free’ German wargame (Kriegsspiel), which became an integral part of German operational planning in the nineteenth and twentieth centuries, thus adding another chapter to the story of the influence of ideas on human history

Onderzoek naar de oorzaken van de slechte bespeelbaarheid van enkele sportvelden in Den Haag

De dienst gemeente-plantsoenen van 's-Gravenhage heeft verzocht aandacht te besteden aan de slechte bespeelbaarheid van verscheidene van hun sportvelden (voetbal en hockey). Het probleem is , dat in natte perioden in herfst en winter te lang water op het veld blijft staan of de toplaag van het terrein te zacht wordt, waardoor het sportveld te vaak voor wedstrijden moet worden afgekeurd. Ook een te gladde toplaag wordt vaak, vooral bij hockey, als minder gewenst beschouwd. Het verzoek om enig onderzoek hield ook verband met het feit dat men de indruk had, dat het bodemkundige aspect bij aanleg en onderhoud van sportvelden nog een verwaarloosd terrein van onderzoek is

A perturbative approximation to DFT/MRCI: DFT/MRCI(2)

We introduce a perturbative approximation to the combined density functional theory and multireference configuration interaction (DFT/MRCI) method. The method, termed DFT/MRCI(2), results from the application of quasi-degenerate perturbation theory and the Epstein-Nesbet partitioning of the DFT/MRCI Hamiltonian matrix. This results in the replacement of the diagonalization of the large DFT/MRCI Hamiltonian with that of a small effective Hamiltonian, and affords orders of magnitude savings in terms of computational cost. Moreover, the DFT/MRCI(2) approximation is found to be of excellent accuracy, furnishing excitation energies with a root mean squared deviation from the DFT/MRCI values of less than 0.03 eV for an extensive test set of organic molecules

Of the Conduct of the Understanding, by John Locke

The editor’s General Introduction is divided into two parts. The first part, ‘Context’, discusses Locke’s analysis of the nature of error, the causes of error and the prevention and cure of error in the Conduct. His enquiry is placed in the context of his way of ideas as given in his Essay concerning Human Understanding. Locke’s two-stage way of ideas, his occupation with our mental faculties and with method form the interrelated main ingredients of his logic of ideas. There is a complicated relation of continuity and change between the content and the structure of this new logic on the one hand and the content and structure of works by both scholastic predecessors (Du Trieu, Smith, Sanderson) and novel philosophers (Descartes, Arnauld, Malebranche) on the other hand. Once this context is taken into account, the Conduct can be understood as work that has a function within the structure of Locke’s logic of ideas that runs parallel to the function of the De sophisticis elenchis in the Aristotelian Organon. The second part of the General Introduction, ‘Text’, gives a description of the relevant MSS, an overview of references to the Conduct in Locke’s correspondence, a history of the genesis of the Conduct until its first publication in 1706 in the Posthumous Works, an analysis of the evidence provided by the MSS on how the Conduct grew out of the Essay, and a statement of the principles that underlie the present editon

Ultrafast X-ray spectroscopy of conical intersections

Ongoing developments in ultrafast X-ray sources offer powerful new means of probing the com- plex non-adiabatically coupled structural and electronic dynamics of photoexcited molecules. These non-Born-Oppenheimer effects are governed by general electronic degeneracies termed conical in- tersections which play a key role, analogous to that of a transition state, in the electronic-nuclear dynamics of excited molecules. Using high level ab initio quantum dynamics simulations, we studied time-resolved X-ray absorption and photoelectron spectroscopy (TRXAS and TRXPS, respectively) of the prototypical unsaturated organic chromophore, ethylene, following excitation to its S2 state. The TRXAS in particular is highly sensitive to all aspects of the ensuing dynamics. These X-ray spectroscopies provide a clear signature of the wavepacket dynamics near conical intersections, related to charge localization effects driven by the nuclear dynamics. Given the ubiquity of charge localization in excited state dynamics, we believe that ultrafast X-ray spectroscopies offer a unique and powerful route to the direct observation of dynamics around conical intersections.Comment: 5 pages, 4 figure

Expressions of self-ageism in four European countries:a comparative analysis of predictors across cultural contexts

Self-ageism has a significant negative impact on older people's ageing experiences and health outcomes. Despite ample evidence on cross-cultural ageism, studies have rarely looked into the way cultural contexts affect self-ageism. In this article, we compare expressions of self-ageism and its possible predictors across four European countries based on two questionnaires in a study sample of 2,494 individuals aged 55 and older. We explore how predictors of self-ageism are moderated by cultural values in a comparative fixed-effects regression model. We empirically show that similarly to ageism, self-ageism is not present in the same way and to the same extent in every country. Moreover, the level to which cultures value hierarchy and intellectual autonomy significantly moderates the association between self-ageism and individual predictors of self-ageism. Our study adds to the small existing body of work on self-ageism by confirming empirically that certain expressions of self-ageism and individual predictors are susceptible to change in different cultural contexts. Our research results suggest that self-ageism interventions may benefit from a culturally sensitive approach and imply that more culturally diverse comparisons of self-ageism are necessary to figure out fitting ways to reduce self-ageism

Epithelium-Free Area in The Thymic Cortex of Rats

The histology of epithelium-free areas in the subcapsular region of the thymus was studied in Wistar rats. Lymphocytes in these areas were CD4/CD8 double-positive, TCR α/β positive in low intensity, and in CD5 labeling either negative or positive in low intensity. There was a high proliferative activity as assessed by bromodeoxyuridine incorporation in vivo and detected by immunohistochemistry. Various macrophage types were observed. They were either large and round to slightly dendritic, or small and dendritic. Most large cells were positive for MHC Class II, and labeled by the antimacrophage antibodies ED1 and ED2. A few cells were strongly positive for Sudan black, Oil red O, nonspecific esterase, and acid phosphatase; they resembled the large rounded macrophages in the corticomedullary zone, although their MHC Class II and ED2 staining was more intense. A few cells showed features of tingible body macrophages, as they contained cellular debris