Characterisation of movement pattern and velocities of stallion spermatozoa depending on donor, season and cryopreservation

The aim of the study was to compare different types of movement pattern and velocities of stallion spermatozoa depending on cryopreservation during breeding and non-breeding season. Ejaculates were collected from four stallions during May (n = 24) and December (n = 24). Parameters of sperm movement were evaluated by computer-aided sperm analysis (CASA) system, and included percentages of motile spermatozoa, different patterns of motility, the velocity, linearity (LIN), amplitude of lateral head displacement (ALH) and beat-cross frequency (BCF). In winter the average percentages of motility were slightly higher compared to the breeding season in May (70.8 ± 12.7% vs. 66.8 ± 12.2%, respectively). Cryopreservation and thawing led to a significant decrease in the number of motile sperm to 11.3 ± 5.8% in May and 15.6 ± 7.0% in December. The pattern of motility was also changed. Detailed analysis by CASA demonstrated that cryopreservation resulted in a shift from the proportions of linear to more non-linear motile spermatozoa and to a significant increase of local motile and hyperactivated spermatozoa. Mean velocity of fresh motile spermatozoa differed between May and December (119.1 ± 43.9 vs. 164.4 ± 66.4 µm/sec, respectively; P < 0.05). Cryopreservation and thawing led to a slight increase of curvilinear velocity (VCL) and straight line velocity (VSL). The motility analysis has shown that the parameters BCF and ALH were highly correlated in stallion spermatozoa (r = -0.67; P < 0.001). The BCF of stallion spermatozoa was slightly reduced in the non-breeding season. Altogether, the influence of factors on the motility of stallion spermatozoa has the following rank order: cryopreservation (P < 0.0001) ≯ stallion (P < 0.001) ≯ season (P < 0.05)

Prolactin Heterogeneity: A Limitation on the Evaluation of Results from Prolactin Assays due to Differences in Immunoassays and the Different Bioactivities of Prolactin Forms

Peer Reviewe

What Shapes Attitudes Toward Paying Taxes? Evidence from Multicultural European Countries

Objectives. Considerable evidence suggests that enforcement efforts cannot fully explain the high degree of tax compliance. To resolve this puzzle of tax compliance, several researchers have argued that citizens' attitudes toward paying taxes, defined as tax morale, helps to explain the high degree of tax compliance. However, most studies have treated tax morale as a black box, without discussing which factors shape it. Additionally, the tax compliance literature provides little empirical research that investigates attitudes toward paying taxes in Europe. Methods. Thus, this article is unique in its examination of citizen tax morale within three multicultural European countries, Switzerland, Belgium, and Spain, a choice that allows far more detailed examination of the impact of culture and institutions using data sets from the World Values Survey and the European Values Survey. Results. The results indicate the tendency that cultural and regional differences affect tax morale. Conclusion. The findings suggest that higher legitimacy for political institutions leads to higher tax morale