Effect of various levels of dissolved oxygen on reactive oxygen species and cryocapacitation-like changes in bull sperm.

The present investigation was carried out to study the effect of various levels of dissolved oxygen (DO) on reactive oxygen species (ROS) and cryocapacitation-like changes in bull sperm. Egg yolk-Tris-glycerol (EYTG) extender was split into four subextenders; viz., Extender I (control; no flushing with liquid nitrogen (LN )), Extender II, Extender III and Extender IV were flushed with LN for 40, 16 and 8 min, respectively.

Partial deoxygenation of extender improves sperm quality, reduces lipid peroxidation and reactive oxygen species during cryopreservation of buffalo (Bubalus bubalis) semen.

The present study was designed to investigate the effect of partial deoxygenation of extender on sperm quality, lipid peroxidation (LPO) and reactive oxygen species (ROS) in buffalo (Bubalus bubalis) during cryopreservation of semen. Semen extender was prepared freshly and split into three sub-extenders [Extender I: control (non-deoxygenated), Extender II (partially deoxygenated by using LN flushing) and Extender III (partially deoxygenated mechanically by vacuum pump)]. Amounts of dissolved oxygen (DO) were determined in all the three extenders and also in post-thaw semen.

Zimbabwean farmers in Nigeria: exceptional farmers or spectacular support?

Since 2004, white commercial farmers displaced under Zimbabwe's fast-track land reform programme have established new successful farms near the central Nigerian town of Shonga. This article explores the basis of that success. It addresses three key questions: (1) What has actually happened near Shonga since 2004? (2) What or who is driving the process of agrarian transformation? And (3) What are the long-term consequences for the peasantry since Nigerian agriculture is still largely peasant-based? It argues that contrary to popular myths of ‘enterprising’ white Zimbabwean farmers, the process is driven by a complex group of actors, including the national and regional states.