This study analyzed the determinants of the productivity of smallholder arable crop farmers with a particular focus on land fragmentation using the Simpson Index as measures of land fragmentation in Imo state of Nigeria. Data collected by using structured questionnaire and interview schedules were analyzed using simple descriptive statistics; Simpson index and regression analysis. Results showe...

background: oxidative stress in teratozoospermic semen samples caused poor assisted reproductive techniques (art) outcomes. among antioxidants, ascorbic acid is a naturally occurring free radical scavenger and as such its presence assists various other mechanisms in decreasing numerous disruptive free radical processes. objective: the main goal of this study was to evaluate potential protective...

background: heat shock protein a2 (hspa2) is correlated with sperm maturity and function. therefore, dysfunctional expression of this gene results in abnormal spermatogenesis. on the other hand, dna damage in spermatozoa is considered to be an important cause of male infertility, and the presence of sperm with dna fragmentation and chromatin abnormalities in human ejaculates is well documented,...

■ Abstract The literature on effects of habitat fragmentation on biodiversity is huge. It is also very diverse, with different authors measuring fragmentation in different ways and, as a consequence, drawing different conclusions regarding both the magnitude and direction of its effects. Habitat fragmentation is usually defined as a landscape-scale process involving both habitat loss and the br...

BACKGROUND In humans, sperm DNA fragmentation rates have been correlated with sperm viability rates. Reduced sperm viability is associated with high sperm DNA fragmentation, while conversely high sperm viability is associated with low rates of sperm DNA fragmentation. Both elevated DNA fragmentation rates and poor viability are correlated with impaired male fertility, with a DNA fragmentation r...

Habitat fragmentation is an issue of primary concern in conservation biology. However. both the concepts of habitat and fragmentation are ill-defined and often misused. We review the habitat concept and examine differences between habitat fragmentation and habitat heterogeneity, and we suggest that habitat fragmentation is both a state (or outcome) and a process. In addition, we attempt to dist...