Africa is rich in natural as well as
human resources which are the basis for the prosperity of a given nation.
Despite its potential the continent is still underdeveloped. Different scholars
have tried to analyze the root causes of under development in Africa in
different perspective. Some from the colonization perspective and others from
the political set up of the continent. Based on this rational, we were
initiated to review different literatures to identify the real causes of
poverty in Africa, and to recommend an appropriate development theory for the
continent. The socio political set up of African countries has a similarity with
those of the East Asian nations which have brought economic progress through
exercising developmental state.
The phylogenetic tree portrays a
relationship between sets of species and represents a model of molecular
evolution. The current forms of species retain many of their ancestral
features, some of which gradually change to help these species adjust to their
environment. We provide a review of phylogenetic construction and validation
methods and its application in cancer analysis. The need of alignment free
methods for sequence comparison is also explored as an alternative to alignment
based methods.
Why do many male birds display specific colorful
patterns on their plumage? The demand-relationship theory explains that beauty
preferences reflect human and birds' desire for approaching some objects; these
patterns look beautiful because they resemble their ideal food sources or
environments. Mutants that have enhanced human and birds' ability and
motivation in finding these were hence selected by nature. Such beauty
preferences of the female birds then selected the male plumage. Some convincing
photos are provided. A statistical analysis about inference "If a bird has
yellow feather then it probably likes eating nectar” shows that this inference
has higher confidence level and conveys more semantic information than
inference "If a person has high triglyceride then he probably also has
fatty liver”.
There is a great need to predict liquid water
saturation in porous layers such as gas diffusion layers (GDL) and micro porous
layers (MPL) of polymer electrolyte membrane fuel cells (PEMFCs) as this is a
key parameter in flooding occurrence which is a limiting factor of PEM fuel
cell performance. Several models have been developed in order to study water
distribution and migration in micro porous layers. These models require heavy
computational efforts and doubt in their applicability to the gas diffusion
layer (GDL). Recently Qin & Hassanizadeh [1] developed a new approach based
on the reduced continua model for modeling multiphase flow through a stack of
thin porous layers. Their approach requires
much less computational efforts and predicts less water flooding in the GDL,
but is using an empirical closure inaccurate model.
