The aim of this study was to check what decide about breeding success in red- backed shrike Lanius collurio: nest-site concealment or parent’s aggressive behaviour. The study was carried out in eastern Poland in 1999–2003, on study plot consisted of 855 ha of extensively agricultural landscape. The effect of nest site concealment and defence of brood by parents on breeding success was determined. In observations only natural nests were used. During the two of 10 days periods after commence of egg laying, no effect of index nest concealment and index of parents aggressiveness was observed. However, in first seven days of life of nestlings, was noticed that breeding success was depended on aggressiveness of parents, in relation to index nest concealment. The results showed behavior (aggression) as an important factor in breeding success of the red-backed shrike.
Optical mapping is a fluorescence-based physiological method to image spreading of action potential in excitable tissues, such as the heart and central nervous system. Because of the requirements for high speed imaging in low light conditions, highly sensitive high-speed cameras together with an optical system with maximum photon efficiency are required. While the optimization of these two components is relatively straightforward, the choice of the perfect light source is less simple; depending on the other (usually fixed) components, various parameters may acquire different weight in decisionmaking process. Here we describe the rationale for building an optical mapping setup and consider the relative advantages and disadvantages of three different commonly available light sources: mercury vapor lamp (HBO), xenon lamp (XBO), and light emitting diode (LED). Using the same optical system (fluorescence macroscope) and high-speed camera (Ultima L), we have tested each of the sources for its ability to provide bright and even illumination of the field of view and measured its temporal fluctuations in intensity. Then we used each in the actual optical mapping experiment using isolated, perfused adult mouse heart or chick embryonic heart to determine the actual signal to noise ratio at various acquisition rates. While the LED sources have undergone significant improvements in the recent past, the other alternatives may still surpass them in some parameters, so LEDs may not be the automatic number one choice for every application., Veronika Olejnickova, David Sedmera., and Obsahuje bibliografii
This cross sectional study focused on how Postural Stability (PS) indicators: body sway deviation (BSD) and body sway velocity (BSV), change with age and their association with levels of social and physical activity. Observational study: 80 older adults (aged: 60-96) were purposefully recruited from two sources: the University of the Third Age (TAU) (n = 35) and a residential care home (CH) (n = 45). Differences in the indicators of PS, approximated through Centre of Pressure (COP) measurements, were assessed by the Romberg Stance Test (Test A) subsequently repeated on 10 cm foam surface (Test B), using a Kistler Dynamometric Platform. The RCH Group was older, had higher BMI and was less socially and physically active, showed more body sway in all indicators compared to TAU group. For all participants body sway velocity (BSV) was significantly correlated with age. The strength of correlation of body sway deviation (BSD) with age was also significant but not as strong. The findings indicate in line with previous studies that deterioration in BSV is associated with poor PS more than deterioration in BSD. and J. Jančová Všetečková, N. Drey
Epileptic afterdischarges (ADs) elicited by electrical stimulation of sensorimotor cortical area were used as a model to study the role of neurotransmitter systems in cortical seizures in three age groups of developing rats. Drugs augmenting inhibition mediated by GABAA receptors were found to suppress ADs in all age groups, their activity was usually more marked in younger than in 25-day-old rat pups. Drugs potentiating GABAB receptors exhibit lower efficacy and more complicated developmental profile than GABAA-ergic drugs. Effects of an antagonist of GABAB receptor – marked prolongation of ADs in all three age groups – suggest an important role of GABAB receptors in arrest of cortical seizures. Drugs affecting glutamate receptors exhibit variable effects, usually better expressed in older animals than in 12-day-old ones. No specific role for ionotropic as well as metabotropic glutamate receptors could be predicted. Activation of adenosinergic inhibitory modulatory system also exhibited anticonvulsant action in the present model. All three neurotransmitter systems probably participate in mechanisms of generation, maintenance and arrest of cortical seizures., P. Mareš, H. Kubová., and Obsahuje bibliografii a bibliografické odkazy