A comparative study on the response of six maize hybrids: two hybrids each from the 1980s (8321-21 and 8425-8), 1990s (9801-11 and 9803-2) and 2000s (0103-11 and 0103-15) to sub-optimal and optimal nitrogen fertilization was conducted in Oke-Oyi, Nigeria. The trials were set up in a split plot with three nitrogen levels (0, 30 and 90 kg N ha -1 ) as a main plot and six hybrids as sub-plots. Significant interactions were observed between hybrid and N level for all characters, with increasing in variation as the level of N decreased. Mean grain yield reductions across eras were 73.8% at no-N and 32.6% at low-N, and those of optimal-N fertilization were 34.3% and 15.7% for 1980s and 1990s genotypes respectively. Depending on N treatment, grain yield varied from 0.67 to 4.89 t ha -1 . Kernel number was most severely reduced by N stress, but had positive and highly significant (p≤0.01) correlation with grain yield at all N levels. Genetic gains in grain yield were 42% (between 1980 and 2000 eras) and 9% (between 1990 and 2000 eras) under optimal-N fertilization. The two modern hybrids of 2000 era (0103-11 and 0103-15) were outstanding for all the agronomic traits and leaf chlorophyll concentration at all N levels. Improving traits associated with fertilizer N response could accelerate rate of genetic gains in maize yields.

Traumatic Brain Injuries (TBI) or head injuries are injuries or trauma to the scalp and or brain caused by an outside force, usually a violent blow or collision to the head by accident or deliberate attack. It can also be called be craniocerebral trauma. TBI are examples of acquired, non-degenerative assault to the brain from an external mechanical force, causing impairment of brain functions, with or without alteration to the mental state or consciousness of the victim. This paper provides a synopsis of the epidemiology and patterns of associated injuries in mild and moderate head injuries in literature. Mild and moderate head injuries were selected because they are by far commoner than severe head injuries and the outcomes are widely varied than severe head injuries. Traumatic brain injury is a global and public health problem, which in the coming years, might be the leading cause of death in Africa. High incidence is found among the adolescent and the adult age group and gender-wise, it is common among the males of the same age group. Likewise, the provision of an ambulance system and standard healthcare facilities to manage 18 patients with a traumatic brain injury can not be overemphasized.