Can a Postmodern Philosopher Teach Modern Philosophy?

This paper considers the following question: how can those whose thought is informed by poststructuralist values, arguments, and training legitimately teach the history of philosophy? In answering this question, three pedagogical approaches to courses in the history of philosophy are considered and criticized: the representational, the phenomenological, and the conversational. Although these three approaches are seemingly exhaustive, each is problematic because the question they attempt to answer rests on the false assumption that there is one, universally right way to teach philosophy and many wrong ways. In rejecting this assumption, the author considers a new, more concrete, and contextualized question concerning teaching philosophy from a postmodern perspective

Evolutionary Markovian Strategies in 2 x 2 Spatial Games

Evolutionary spatial 2 x 2 games between heterogeneous agents are analyzed using different variants of cellular automata (CA). Agents play repeatedly against their nearest neighbors 2 x 2 games specified by a rescaled payoff matrix with two parameteres. Each agent is governed by a binary Markovian strategy (BMS) specified by 4 conditional probabilities [p_R, p_S, p_T, p_P] that take values 0 or 1. The initial configuration consists in a random assignment of "strategists" among the 2^4= 16 possible BMS. The system then evolves within strategy space according to the simple standard rule: each agent copies the strategy of the neighbor who got the highest payoff. Besides on the payoff matrix, the dominant strategy -and the degree of cooperation- depend on i) the type of the neighborhood (von Neumann or Moore); ii) the way the cooperation state is actualized (deterministically or stochastichally); and iii) the amount of noise measured by a parameter epsilon. However a robust winner strategy is [1,0,1,1].Comment: 18 pages, 8 figures (7 of these figures contain 4 encapsulapted poscript files each

Quality of seminal fluids varies with type of stimulus at ejaculation.

The theory of ejaculate economics was mainly built around different sperm competition scenarios but also predicts that investments into ejaculates depend on female fecundity. Previous tests of this prediction focused on invertebrates and lower vertebrate, and on species with high female reproductive potential. It remains unclear whether the prediction also holds for polygynous mammals with low female reproductive potential (due to low litter size and long inter-birth intervals). We used horses (Equus caballus) to experimentally test whether semen characteristics are adjusted to the oestrous cycle of the mare a stallion is exposed to during few moments before ejaculation. We analysed 122 weekly semen samples collected from 16 stallions during exposure to either an oestrous or a dioestrous mare. Semen volume and the rate of motile sperm were higher when stallions were exposed to an oestrous than to a diestrous mare, while total sperm counts and sperm velocity remained unchanged. Sperm collected after exposure to an oestrous mare also showed reduced oxidative degeneration of cell membranes over a period of 48 hours. We conclude that stallions invest more into their seminal fluids when the chance of fertilization is elevated, and that this adjustment of ejaculate quality can happen very quickly

The air pressure effect on the homogeneous nucleation of carbon dioxide by molecular simulation

Vapour-liquid equilibria (VLE) and the influence of an inert carrier gas on homogeneous vapour to liquid nucleation are investigated by molecular simulation for quaternary mixtures of carbon dioxide, nitrogen, oxygen, and argon. Canonical ensemble molecular dynamics simulation using the Yasuoka-Matsumoto method is applied to nucleation in supersaturated vapours that contain more carbon dioxide than in the saturated state at the dew line. Established molecular models are employed that are known to accurately reproduce the VLE of the pure fluids as well as their binary and ternary mixtures. On the basis of these models, also the quaternary VLE properties of the bulk fluid are determined with the Grand Equilibrium method. Simulation results for the carrier gas influence on the nucleation rate are compared with the classical nucleation theory (CNT) considering the "pressure effect" [Phys. Rev. Lett. 101: 125703 (2008)]. It is found that the presence of air as a carrier gas decreases the nucleation rate only slightly and, in particular, to a significantly lower extent than predicted by CNT. The nucleation rate of carbon dioxide is generally underestimated by CNT, leading to a deviation between one and two orders of magnitude for pure carbon dioxide in the vicinity of the spinodal line and up to three orders of magnitude in presence of air as a carrier gas. Furthermore, CNT predicts a temperature dependence of the nucleation rate in the spinodal limit, which cannot be confirmed by molecular simulation

Embryo survival in the oviduct not significantly influenced by major histocompatibility complex social signaling in the horse.

The major histocompatibility complex (MHC) influences sexual selection in various vertebrates. Recently, MHC-linked social signaling was also shown to influence female fertility in horses (Equus caballus) diagnosed 17 days after fertilization. However, it remained unclear at which stage the pregnancy was terminated. Here we test if MHC-linked cryptic female choice in horses happens during the first days of pregnancy, i.e., until shortly after embryonic entrance into the uterus and before fixation in the endometrium. We exposed estrous mares to one of several unrelated stallions, instrumentally inseminated them with semen of another stallion, and flushed the uterus 8 days later to test for the presence of embryos. In total 68 embryos could be collected from 97 experimental trials. This success rate of 70.1% was significantly different from the mean pregnancy rate of 45.7% observed 17 days after fertilization using the same experimental protocol but without embryo flushing. Embryo recovery rate was not significantly dependent on whether the mares had been socially exposed to an MHC-dissimilar or an MHC-similar stallion. These observations suggest that MHC-linked maternal strategies affect embryo survival mainly (or only) during the time of fixation in the uterus

Unraveling the "Pressure-Effect" in Nucleation

The influence of the pressure of a chemically inert carrier-gas on the nucleation rate is one of the biggest puzzles in the research of gas-liquid nucleation. Different experiments can show a positive effect, a negative effect, or no effect at all. The same experiment may show both trends for the same substance depending on temperature, or for different substances at the same temperature. We show how this ambiguous effect naturally arises from the competition of two contributions: nonisothermal effects and pressure-volume work. Our model clarifies seemingly contradictory experimental results and quantifies the variation of the nucleation ability of a substance in the presence of an ambient gas. Our findings are corroborated by results from molecular dynamics simulation and might have important implications since nucleation in experiments, technical applications, and nature practically always occurs in the presence of an ambient gas.Comment: 4 pages, 3 figures. v2: All citations now appear correctly. v3: Updated one point in Fig.

Contracting in the days of eBusiness

Putting electronic business on a sound foundation --- model theoretically as well as technologically --- has to be seen as a central challenge for research as well as for commercial development. This paper concentrates on the discovery and the negotiation phase of concluding an agreement based on a contract. We present a methodology how to come seamlessly from a many-to-many relationship in the discovery phase to a one-to-one relationship in the contract negotiation phase. Making the content of the contracts persistent is achieved by reconstructing contract templates by means of mereologic (logic of the whole-part relation). Possibly nested sub-structures of the contract template are taken as a basis for negotiation in a dialogical way. For the negotiation itself the contract templates are extended by implications (logical) and sequences (topical)

MHC-correlated preferences in diestrous female horses (Equus caballus).

Genes of the major histocompatibility complex (MHC) have been shown to influence communication in many vertebrates, possibly with context-specific MHC-correlated reactions. Here we test for MHC-linked female preferences in the polygynous horse (Equus caballus) by repeatedly exposing 19 mares to a group of seven sexually experienced stallions. Each mare was tested four times during two consecutive reproductive cycles, twice during estrus and twice during diestrus. Male plasma testosterone concentrations were determined from weekly blood samples, and equine leukocyte antigen (ELA) class I and II alleles were determined serologically at the end of the experiments. Perception of male attractiveness was strongly dependent on estrous cycle: mean preference scores did not correlate for mares in diestrus and estrus and varied more during estrus than during diestrus. We found elevated female interests for MHC-dissimilar stallions, but only during diestrus, not during estrus. Female preferences were not significantly predicted by mean male testosterone plasma concentrations. However, testosterone concentrations changed during the 11 weeks of the experiment. By the end of the experiment, average testosterone concentration was significantly correlated to the average number of MHC alleles the stallions shared with the mares. We conclude that the MHC affects female preferences for stallions, but non-MHC linked male characteristics can overshadow effects of the MHC during estrus

Optimization of crystal nucleation close to a metastable fluid-fluid phase transition

The presence of a metastable fluid-fluid critical point is thought to dramatically influence the crystallization pathway, increasing the nucleation rate by many orders of magnitude over the predictions of classical nucleation theory. We use molecular dynamics simulations to study the kinetics of crystallization in the vicinity of this metastable critical point and throughout the metastable fluid-fluid phase diagram. To quantitatively understand how the fluid-fluid phase separation affects the crystal nucleation, we evaluate accurately the kinetics and reconstruct the thermodynamic free-energy landscape of crystal formation. Contrary to expectations, we find no special advantage of the proximity of the metastable critical point on the crystallization rates. However, we find that the ultrafast formation of a dense liquid phase causes the crystallization to accelerate both near the metastable critical point and almost everywhere below the fluid-fluid spinodal line. These results unveil three different scenarios for crystallization that could guide the optimization of the process in experiments