h. akhlaghi

It has become established that Helicobacter pullorum could be isolated from raw chicken meat.

This study was aimed to develop a novel culture method (protocol B) to isolate H. pullorum from chicken meat by adding some modifications to the traditional culture method (protocol A), and as a consequence to compare their sensitivity, specificity, and the accuracy of these methods with polymerase chain reaction (PCR) test.

400 chicken meat samples were collected from various retail markets and supermarkets. Each sample was processed by protocol A, protocol B, and PCR test.

Out of 400 samples, 77 (19.25%), and 163 (40.75%) were culture-positive by protocol A and protocol B, respectively. Using PCR test as a gold standard, 196 (49%) samples were identified as H. pullorum. The specificity for both protocols was determined 100%, while the sensitivity of protocol B and protocol A was assessed 83% and 39%, respectively. Also, the higher and lower accuracy belonged to protocol B (92%) and protocol A (70%), respectively.

The methodology designed herein can provide a suitable, approximately sensitive, specific, and accurate method to cultivate H. pullorum from chicken meat.

Transitional boundary layer over a pitching airfoil at low Reynolds number (Re = 2.7×10^5) is experimentally investigated through the space-frequency and time-frequency analyses of hot-film signals. Boundary layer events are visualized based on the space-frequency and time-frequency plots. The precursor phenomena for turbulent as well as fully separated flows are presented based on the time-frequency analysis. A new technique based on the time-frequency analysis of hot-film signals is presented to measure the transition onset as well as the relaminarization locations. This technique is based on the analysis of high-frequency disturbances of the measured data. Special attention is focused on the spatial/temporal progression of the transition onset and the relaminarization points, compared to the static values, for different oscillation frequencies and amplitudes. Investigations are performed prior to, within and beyond the static stall angle of attack conditions. The results obtained by the new technique will be discussed and compared with the observations from the previous investigators.