Technology adoption in small-scale agriculture

This study sets out to explore one of the most important questions for alleviating poverty in sub-Saharan Africa namely: why are advancements in agricultural technology not taking root in this region? Using data from deep interviews of 42 smallscale farmers in Ghana and Cameroon, a conceptual analysis of drivers and factors of agricultural technology adoption in this region is made and represented as causal loop diagrams. Interviews also provide a basis for weighting factors that farmers consider before adopting a new technology. These weights are then used to run a systems dynamics model with a hypothetical population of 10.000 farmers to see the effects of different drivers of technology adoption on the adoption rate and number of adopters over a 25 year period. Results show that most farmers have a bethedging strategy as they try to minimize risks of production failures. While certain factors like scale of production, long-term considerations, the history of success of past technologies, and the endorsement of technologies by opinion leaders may be important, many other factors do influence decisions to adopt new technologies. This limits any silver bullet strategy towards solving the problem of limited diffusion of agricultural technologies in this region. Addressing such a problem therefore calls for a much more holistic approach

Comparative Genomic Characterization of Francisella tularensis Strains Belonging to Low and High Virulence Subspecies

Tularemia is a geographically widespread, severely debilitating, and occasionally lethal disease in humans. It is caused by infection by a gram-negative bacterium, Francisella tularensis. In order to better understand its potency as an etiological agent as well as its potential as a biological weapon, we have completed draft assemblies and report the first complete genomic characterization of five strains belonging to the following different Francisella subspecies (subsp.): the F. tularensis subsp. tularensis FSC033, F. tularensis subsp. holarctica FSC257 and FSC022, and F. tularensis subsp. novicida GA99-3548 and GA99-3549 strains. Here, we report the sequencing of these strains and comparative genomic analysis with recently available public Francisella sequences, including the rare F. tularensis subsp. mediasiatica FSC147 strain isolate from the Central Asian Region. We report evidence for the occurrence of large-scale rearrangement events in strains of the holarctica subspecies, supporting previous proposals that further phylogenetic subdivisions of the Type B clade are likely. We also find a significant enrichment of disrupted or absent ORFs proximal to predicted breakpoints in the FSC022 strain, including a genetic component of the Type I restriction-modification defense system. Many of the pseudogenes identified are also disrupted in the closely related rarely human pathogenic F. tularensis subsp. mediasiatica FSC147 strain, including modulator of drug activity B (mdaB) (FTT0961), which encodes a known NADPH quinone reductase involved in oxidative stress resistance. We have also identified genes exhibiting sequence similarity to effectors of the Type III (T3SS) and components of the Type IV secretion systems (T4SS). One of the genes, msrA2 (FTT1797c), is disrupted in F. tularensis subsp. mediasiatica and has recently been shown to mediate bacterial pathogen survival in host organisms. Our findings suggest that in addition to the duplication of the Francisella Pathogenicity Island, and acquisition of individual loci, adaptation by gene loss in the more recently emerged tularensis, holarctica, and mediasiatica subspecies occurred and was distinct from evolutionary events that differentiated these subspecies, and the novicida subspecies, from a common ancestor. Our findings are applicable to future studies focused on variations in Francisella subspecies pathogenesis, and of broader interest to studies of genomic pathoadaptation in bacteria