In order to support his revolutionary view on scientific change, Kuhn suggests that there exist two separate aspects of the theory-change from Newtonian to Einsteinian physics that support his incommensurability thesis. For the evidence of his thesis, Kuhn offers the conceptual change in the meaning of the notion of “mass” in the theory-change. And he claims the absence of any neutral observational basis to evaluate the strengths of the two theories. This essay argues that these two cases fail to support his incommensurability thesis.
We studied the possible role of clutch crypsis in antipredator behaviour in two related species of ground-nesting waders with camouflaged eggs, the northern lapwing (Vanellus vanellus) and the little ringed plover (Charadrius dubius). We examined whether this behaviour appears regularly in both species and tested the difference in the use of this trait between the two species. The results suggest that both charadriids rely on egg crypsis as a reasonable strategy toward avian nest predators. However, the larger and more conspicuous lapwings use it less frequently than plovers, probably because they rather rely on body size and aggressiveness combined with colonial breeding. Smaller and solitary little ringed plovers tended to hide the nest location more thoroughly than lapwings, probably due to their limited ability to defend the nest actively. Instead of aggressive attacks, they use alternative behavioural elements intended to deceive predators, namely incubation-feigning. Although egg crypsis is regularly used as a passive strategy for protecting nests against predators in both species, it seems to be unprofitable as an exclusive form of nest protection. The birds combine it with other behavioural elements, such as the above mentioned aggressiveness or incubation-feigning.
Drug abuse of pregnant women is a growing problem. The effect of prenatal drug exposure may have devastating effect on development of the offsprings that may be long-term or even permanent. One of the most common drug abused by pregnant women is methamphetamine (MA), which is also the most frequently abused illicit drug in the Czech Republic. Our previous studies demonstrated that prenatal MA exposure alters behavior, cognition, pain and seizures in adult rats in sex-specific manner. Our most recent studies demonstrate that prenatal MA exposure makes adult rats more sensitive to acute injection of the same or related drugs than their controls. The aim of the present study was to examine the effect of prenatal MA exposure on drugseeking behavior of adult male rats tested in the Conditioned place preference (CPP). Adult male rats were divided to: prenatally MA-exposed (5 mg/kg daily for the entire prenatal period), prenatally saline-exposed (1 ml/kg of physiological saline) and controls (without maternal injections). The following drugs were used in the CPP test in adulthood: MA (5 mg/kg), amphetamine (5 mg/kg), cocaine (5 and 10 mg/kg), morphine (5 mg/kg), MDMA (5 mg/kg) and THC (2 mg/kg). Our data demonstrated that prenatally MA-exposed rats displayed higher amphetamine-seeking behavior than both controls. MA as well as morphine induced drug-seeking behavior of adult male rats, however this effect did not differ based on the prenatal MA exposure. In contrast, prenatal MA exposure induced rather tolerance to cocaine than sensitization after the conditioning in the CPP. MDMA and THC did not induce significant effects. Even though the present data did not fully confirmed our hypotheses, future studies are planned to test the drug-seeking behavior also in self-administration test., R. Šlamberová, ... [et al.]., and Obsahuje seznam literatury