The causes of nomadism, migration, and decline in vertebrates are debated issues in the ecological sciences. Literature suggests nomadism may arise in species that specialize in granivory, nectivory, or the utilization of rodent outbreaks. Migration is thought to arise as a result of the exploitation of certain scarce or variable food resources. Species decline is hypothesized to be the result ...

Ethiopia's childhood mortality has continued to decline although at a swift pace. The drop in urban childhood mortality decline, duration of breastfeeding is the principle reason for the overall decline in mortality trends in Ethiopia. Data from the Ethiopian Demographic and Health Surveys 2000 and 2005 were used. Indirect estimation of Brass and Trussell's methods were adopted. Selected demogr...

Last decades have witnessed a progressing decline of social trust, which has been predominantly linked to worsening economic conditions and increasing social inequality. In the present research we propose a different type of explanation for the observed decline - cognitive load related to technological development and the accelerating pace of modern life. In an experimental study participants p...

This paper reviews the progress made in the assessment of water resources in South Africa over the past 60 years by examining 5 major studies that were undertaken in this period. These studies illustrate how the exponential growth in computer power and the concomitant development of highly sophisticated tools have changed the manner in which our water resources have been appraised, allowing us ...

BACKGROUND Humanity faces many great challenges. Some already appear imposing, yet grow relentlessly in seriousness and complexity. Critical resources are in decline in much of the world. Quantities and qualities of clean air, fresh water and topsoil (1) are outstripping their renewal rates. Production of non-renewable resources such as oil has peaked in most of the world. Climate change and in...

Resource construction employment grew rapidly during the investment phase of the resources boom. However, both investment and employment in the resources sector peaked in 2013 and are expected to decline over coming years. A range of sources suggest that the earlier increase in resource construction employment largely drew on workers with experience in other types of construction, and that dema...

Individual differences in cognitive performance increase from early to late adulthood, likely reflecting influences of a multitude of factors. We hypothesize that losses in neurochemical and anatomical brain resources in normal aging modulate the effects of common genetic variations on cognitive functioning. Our hypothesis is based on the assumption that the function relating brain resources to...

In this study, we evaluated an associative deficit hypothesis. This hypothesis suggests that the deficit seen in the episodic memory performance of older adults is due, in considerable part, to older adults' difficulty in binding together unrelated components of an episode into a cohesive entity (Naveh-Benjamin, 2000). The study extended the conditions under which older adults show a differenti...