Hard- and soft-line responses to Pereboom’s four-case manipulation argument

Derk Pereboom has advanced a four-case manipulation argument that, he claims, undermines both libertarian accounts of free action not committed to agent-causation and compatibilist accounts of such action. The first two cases are meant to be ones in which the key agent is not responsible for his actions owing to his being manipulated. We first consider a “hard-line” response to this argument that denies that the agent is not morally responsible in these cases. We argue that this response invites a dialectically uncharitable reading of the argument. We then propose an alternative interpretation; it affirms that, at least prima facie, the manipulated agent in the first two cases is not responsible. Finally, we question Pereboom’s rationale for why the manipulation in these cases subverts responsibility.     

Sensitive Spectroscopic Detection of Large and Denatured Protein Aggregates in Solution by Use of the Fluorescent Dye Nile Red

The fluorescent dye Nile red was used as a probe for the sensitive detection of large, denatured aggregates of the model protein β-galactosidase (E. coli) in solution. Aggregates were formed by irreversible heat denaturation of β-galactosidase below and above the protein’s unfolding temperature of 57.4°C, and the presence of aggregates in heated solutions was confirmed by static light scattering. Interaction of Nile red with β-galactosidase aggregates led to a shift of the emission maximum (λ _max) from 660 to 611 nm, and to an increase of fluorescence intensity. Time-resolved fluorescence and fluorescence correlation spectroscopy (FCS) measurements showed that Nile red detected large aggregates with hydrodynamic radii around 130 nm. By steady-state fluorescence measurements, it was possible to detect 1 nM of denatured and aggregated β-galactosidase in solution. The comparison with size exclusion chromatography (SEC) showed that native β-galactosidase and small aggregates thereof had no substantial effect on the fluorescence of Nile red. Large aggregates were not detected by SEC, because they were excluded from the column. The results with β-galactosidase demonstrate the potential of Nile red for developing complementary analytical methods that overcome the size limitations of SEC, and can detect the formation of large protein aggregates at early stages.     

Certification of contents of aromatic hydrocarbons in charcoal tubes – CRM 562

A Certified Reference Material (CRM) for determination of aromatic hydrocarbons in air was developed. The CRM 562 consists of aromatic hydrocarbons sorbed on charcoal in glass tubes. Initial feasibility studies established that a homogeneous and stable batch could be prepared. Three intercomparisons prior to the certification allowed the identification of various sources of error. Then, a batch of about 3000 tubes was charged and certified on the basis of analyses carried out in 15 European laboratories. The preparation of the reference material and the results of the certification exercise is described. An overview on the analytical techniques used and the quality control guidelines are also presented. The certified values are 15.0 ± 0.4 μg benzene, 147.3 ± 3.8 μg toluene, 96.4 ± 2.5 μg m-xylene and 93.0 ± 2.9 μg o-xylene per tube. This reference material is recommended for quality control of measurements in the field of occupational hygiene.     

The time-dependent rheology of fermenting wheat flour dough: effects of salt and sugar

The in situ study of the linear viscoelastic behaviour of complex biological materials with changing volume, such as fermenting dough, poses great challenges to the rheologist. The aim of this study is to develop a new methodology involving a parallel-plate setup with an adjustable gap, to enable time-tracking of the dynamic moduli and density of fermenting dough. Frequency sweep snapshots at specific points in time were obtained in multiwave mode to reduce measurement times, and overfilling effects were taken into account by establishing a calibration curve with unfermented dough. The new test protocol allowed to distinguish the rheological impact of the CO₂ gas from that of the other metabolites produced during fermentation. A further validation of the test protocol was achieved by studying the impact of sugar and salt on the fermentation kinetics, for which the results of the oscillatory tests were combined with gas production data obtained with a rheofermentometer.     

Rupture energy and wetting behavior of pendular liquid bridges in relation to the spherical agglomeration process

A novel micro force balance (MFB) is used to investigate the rupture energy of a silicon oil liquid bridge formed in water between two glass particles of either the same or dissimilar surface energy. Rupture energies are integrated from force curves and compared with the models proposed by Simons et al. (Chem. Eng. Sci. 49 (1994) 2331) and Pitois et al. (Eur. Phys. J. B 23 (2001) 79). The latter showed slightly better agreement to the experimental data. Glass ballotini ( approximately 100 microm diameter) are either silanized, in order to increase their wettability toward the oil binder, or kept untreated. Results showed how the interaction between the binder and the particle influences the geometry, the capillary pressure, the force, and the rupture energy of the liquid bridge. Higher values of force and liquid bridge energy were measured between particles characterized by higher interaction (silanized-silanized configuration). A thermodynamic approach to the evaluation of the energy stored in a liquid bridge is also proposed. The mechanical work done to stretch apart the liquid bridge is evaluated as the difference of internal and hysteresis energy between the initial and the rupture configuration of the bridge. This approach showed good agreement with the experimental data only for liquid bridges formed between silanized and untreated glass particles.     

Statistical risk evaluation applied to (Belgian) car insurance

Before applying actuarial techniques to determine different subportfolios and adjusted insurance premiums for contracts that belong to a more or less heterogeneous portfolio, e.g. using credibility theory, it is worthwhile performing a statistical analysis on the relevant factors influencing the risk in the portfolio. Also the distributional behaviour of the portfolio should be examined. In this paper such a programme is presented for car insurance data using logistic regression, correspondence analysis, and statistical techniques from survival analysis. The specific mechanisms governing large claims in such portfolios will also be described. This work is based on a representative sample from Belgian car insurance data from 1989.     

Characterizations of finite classical polar spaces by intersection numbers with hyperplanes and spaces of codimension 2

In this article we show that non-singular quadrics and non-singular Hermitian varieties are completely characterized by their intersection numbers with respect to hyperplanes and spaces of codimension 2. This strongly generalizes a result by Ferri and Tallini [5] and also provides necessary and sufficient conditions for quasi-quadrics (respectively their Hermitian analogues) to be non-singular quadrics (respectively Hermitian varieties).     

Time reversal imaging for sensor networks with optimal compensation in time

Using extensive numerical simulations, several distributed sensor imaging algorithms for localized damage in a structure are analyzed. Given a configuration of ultrasonic transducers, a full response matrix for the healthy structure is assumed known. It is used as a basis for comparison with the response matrix that is recorded when there is damage. Numerical simulations are done with the wave equation in two dimensions. The healthy structure contains many scatterers. The aim is to image point-like defects with several regularly distributed sensors. Because of the complexity of the environment, the recorded traces have a lot of delay spread and travel time migration does not work so well. Instead, the traces are back propagated numerically assuming that there is some knowledge of the background. Since the time at which the back propagated field will focus on the defects is unknown, the Shannon entropy or the bounded variation norm of the image is computed and the time where it is minimal is picked. This imaging method performs well because it produces a tight image near the location of the defects at the time of refocusing. When there are several defects, the singular value decomposition of the response matrix is also carried out.