Seasonal Changes in Testicular Cell Morphology in Domestic Male Cats (Felis catus)

The aim of this study was to asses the variation in the morphology of the seminal epithelium in relation to natural photoperiod in male cats. Tom cats (n = 240) were castrated every other week throughout the year. Each testis was fixed in Bouin's solution and cut into sections. The percentage of tubules with round spermatids (RS), elongated spermatids (ES), tailed spermatids (TS), mature spermatids (MS) and the number of Sertoli cells (SC) and Leydig cells (LC) were recorded in each sample. Testicles from males during short days (SHD) had a higher percentage of tubules with RS and ES compared to testicles from males during long days (LHD, 31.3 ± 0.6 vs 2.1 ± 0.6%, p < 0.001; 30.9 ± 0.7 vs 11.0 ± 0.7%, p < 0.001). Conversely, testicles from males during SHD had a lower percentage of tubules with TS and MS compared to testicles from males during LHD (24.5 ± 0.8 vs 29.7 ± 0.8%, p < 0.01; 13.1 ± 1.2 vs 57.0 ± 1.2%, p < 0.01). Furthermore, testicles from males during SHD had a higher number of SC and lower number of LC compared to testicles from males during LHD (11.4 ± 0.1 vs 8.0 ± 0.1%, p < 0.01; 19.2 ± 1.0 vs 38.0 ± 1.0%, p < 0.01). In conclusion, there are seasonal changes in testis cell morphology in the tom which may be related to seasonal sperm production.     

An improved solution for the infiltration advance problem in irrigation hydraulics

The irrigation advance problem in irrigation hydraulics has been spread across the engineering and soil science literature over a number of decades. The Lewis–Milne framework has been used extensively, but one problem has been to find a suitable infiltration equation. The infiltration advance solutions of Philip and Farrell, and Collis-George and Freebairn are compared to a new solution based on the linear soil infiltration equation. It is shown that the linear soil solution is able to give similar results to the Philip and Farrell solution at early stages of infiltration when this is valid, and the Collis-George and Freebairn solution at longer times when this is valid. The linear soil infiltration advance solution presented here is the first using physically meaningful parameters which is able to give adequate infiltration and advance behaviour over all time scales. To further test the linear soil concept, we inversely fit irrigation advance data to get the sorptivity, saturated hydraulic conductivity and infiltration rate behaviour of the soil using all three infiltration equations. The linear soil is shown to give the best fit for the infiltration behaviour to the measured results with an average r ² of 0.98 compared to 0.84 for Philip and Farrell and 0.77 for Collis-George and Freebairn. The linear soil model was also the best fit using other statistical tests such as RMSE and RSR.