Growth and Poverty in Burkina Faso: A Reassessment of the Paradox

Previous poverty assessments for Burkina Faso were due to the neglect of some important methodological issues misleading and led to the so-called 'Burkinabè Growth-Poverty-Paradox', i.e. relatively sustained macro-economic growth, but almost constant poverty. We estimate that poverty significantly decreased between 1994 and 2003 at least on the national level, i.e. growth was in contrast to what previous poverty estimates suggested 'pro-poor'. However, we also demonstrate that between 1994 and 1998 poverty indeed increased despite a good macro-economic performance. This was due to a severe drought and a resulting profound deterioration of the purchasing power of the poor; an issue which was also overseen by previous studies.Poverty; Pro-poor growth; Differential inflation; Sub-Saharan Africa; Burkina Faso

Constrained Hybrid Monte Carlo algorithms for gauge-Higgs models

We develop Hybrid Monte Carlo (HMC) algorithms for constrained Hamiltonian systems of gauge- Higgs models and introduce a new observable for the constraint effective Higgs potential. We use an extension of the so-called Rattle algorithm to general Hamiltonians for constrained systems, which we adapt to the 4D Abelian-Higgs model and the 5D SU(2) gauge theory on the torus and on the orbifold. The derivative of the potential is measured via the expectation value of the Lagrange multiplier for the constraint condition and allows a much more precise determination of the effective potential than conventional histogram methods. With the new method, we can access the potential over the full domain of the Higgs variable, while the histogram method is restricted to a short region around the expectation value of the Higgs field in unconstrained simulations, and the statistical precision does not deteriorate when the volume is increased. We further verify our results by comparing to the one-loop Higgs potential of the 4D Abelian-Higgs model in unitary gauge and find good agreement. To our knowledge, this is the first time this problem has been addressed for theories with gauge fields. The algorithm can also be used in four dimensions to study finite temperature and density transitions via effective Polyakov loop actions.Comment: added comparison to one-loop potential in section 3.3, improved text; version accepted for publication in Computer Physics Communication

Extinction of gene expression in somatic cell hybrids. a reflection of important regulatory mechanisms?

Extinction in somatic cell hybrids is a multifactorial process that leads to loss of cell-type-specific gene expression. The underlying mechanisms are thought to mirror, at least in part, the repertoire of regulatory mechanisms controlling mammalian cell differentiation

Extinction of tyrosine aminotransferase gene activity in somatic cell hybrids involves modification and loss of several essential transcription factors

Extinction is defined as the loss of cell type-specific gene expression that occurs in somatic cell hybrids derived by fusion of cells with dissimilar phenotypes. To explore the basis of this dominant-negative regulation, we have studied the activities of the control elements of the liver-specific gene encoding tyrosine aminotransferase (TAT) in hepatoma/fibroblast hybrid crosses. We show that extinction in complete somatic cell hybrids is accompanied by the loss of activity of all known cell type-specific control elements of the TAT gene. This inactivity is the result of first, lack of expression of genes coding for the transcriptional activators HNF4 and HNF3[~ and HNF33,, which bind to essential elements of the enhancers; and second, loss of in vivo binding and activity of ubiquitous factors to these enhancers, including CREB, which is the target for repression by the tissue-specific extinguisher locus TSE1. Complete extinction of TAT gene activity is therefore a multifactorial process affecting all three enhancers controlling liver-specific and hormone-inducible expression. It results from lack of activation, rather than active repression, and involves both post-translational modification and loss of essential transcriptional activators