An alternative to Kitcher's theory of conceptual progress and his account of the change of the gene concept

The present paper discusses Kitcher’s framework for studying conceptual change and progress. Kitcher’s core notion of reference potential is hard to apply to concrete cases. In addition, an account of conceptual change as change in reference potential misses some important aspects of conceptual change and conceptual progress. I propose an alternative framework that focuses on the inferences and explanations supported by scientific concepts. The application of my approach to the history of the gene concept offers a better account of the conceptual progress that occurred in the transition from the Mendelian to the molecular gene than Kitcher’s theory

Proton charge radius from electron scattering

The rms-radius $R$ of the proton charge distribution is a fundamental quantity needed for precision physics. This radius, traditionally determined from elastic electron-proton scattering via the slope of the Sachs form factor $G_e(q^2)$ extrapolated to momentum transfer $q^2$=0, shows a large scatter. We discuss the approaches used to analyze the e-p data, partly redo these analyses in order to identify the sources of the discrepancies, and explore alternative parameterizations. The problem lies in the model dependence of the parameterized $G(q)$ needed for the extrapolation. This shape of $G(q<q_{min})$ is closely related to the shape of the charge density $\rho (r)$ at large radii $r$, a quantity which is ignored in most analyses. When using our {\em physics} knowledge about this large-$r$ density together with the information contained in the high-$q$ data, the model dependence of the extrapolation is reduced and different parameterizations of the pre-2010 data yield a consistent value for $R = 0.887 \pm 0.012fm$. This value disagrees with the more precise value $0.8409 \pm 0.0004 fm$ determined from the Lamb shift in muonic hydrogen.Comment: To be published in special issue of Atoms "High precision mesurements of fundamental constants

The impact of inflation on long-term housing loans

The extension of long-term loans, e.g. to finance housing, is adversely affected by inflation. For one thing, the higher nominal interest rates charged by the banks in response to inflation mean that borrowers have to make (nominally) higher interest payments, which unnecessarily reduces their borrowing capacity. For another, long-term loans with variable interest rates increase the probability that borrowers will become unable to meet their payment obligations. The present paper examines these two assertions in detail. At the same time, it presents a concept for substantially reducing the weaknesses of conventional lending methodologies. We start by investigating the consequences of a stable inflation rate on the borrowing capacity of credit clients, then go on to analyze the impact of fluctuating inflation rates on the risk of default

Sulfur and baking-quality of breadmaking wheat

It is well known in biological science that all factors applied to living organisms (light, water, warmth, fertilizers etc.) show an optimum, when their input is increased. Healthy organisms and sus-tainable systems are, on the long run, only achieved when care is taken not to destroy this equilibrium of factors producing an optimum. With regard to the baking quality of wheat breeders and cereal scientists obviously failed to achieve this aim by breeding their cultivars on the background of ample S depositions in the ecosystems. They (involuntarily) selected plants showing definite characteristics of S deficiency (higher proportions of HMW-glutenin, stronger gluten and dough) even under conditions of ample S supply. I suppose they also selected plants with a high warmth susceptibility as this also delivers firm protein structure. When this environ-mental pollution was stopped and S supplies returned to natural conditions, even with a non S craving plant like wheat, problems arose with the gluten structure as doughs turned out so strong that the baking volume decreased. So one may ask, particularly with regard to S, if the plant constitutions of our modern wheat cultivars are still harmonious and in balance. And as a consequence ot that also the nutritional quality of these cultivars is rather questionable