Food Pricing Policy and Rural Poverty: Insights from Maize in Kenya

This study estimates the effects on poverty resulting from maize price changes associated with the operations of the maize marketing board in Kenya. We consider both supply and demand responses and the accompanying adjustments in rural labor markets in estimating a second order approximation to equilibrium income changes. We then use stochastic dominance techniques to generate poverty rankings between the distribution of income with the effects of the government marketing operations and the distribution of counterfactual incomes. This approach effectively addresses concerns regarding the sensitivity of poverty estimates to the type of poverty measure used. Results indicate that the price-elevating effects of government maize marketing operations have exacerbated rural poverty in all regions of the country except the region from which the largest part of surplus maize originates.Kenya, income transfers, maize policy, Crop Production/Industries, Food Security and Poverty, C22, O2, Q13, Q18,

Smallholder Farming Under Increasingly Difficult Circumstances: Policy and Public Investment Priorities for Africa

Agricultural and Food Policy,

High Voltage Coefficient Piezoelectric Materials For Underwater Transducer Applications

An investigation into the piezoelectric voltage coefficient (gij) has been carried out from a fundamental materials science perspective. For single crystals, the tetragonality is found to be the structural driving force for high polarisation and gij coefficients. Textured ceramics also exhibit high gij values due to the degree of grain and polarisation orientation. For polycrystalline ceramics, the presence of grains and grain boundaries and the associated elastic stresses suppresses gij at high tetragonalities. Landau-Devonshire theory has been applied to BiFeO3-PbTiO3 to highlight its potential as a high gij candidate. Initially the compositional dependence is modelled by applying Vegard's law between the Landau coefficients of each end member. Whilst this manages to replicate the experimentally constructed phase diagram, the spontaneous strain behaviour is incorrectly described. The second method models the compositional dependence as an external tensile stress which acts to elongate the unit cell within the tetragonal phase, and as a shear stress within the rhombohedral region to reduce the angle between the polarisation and [001]. Using this method, the g33, g31, g15 and gh for 0.70BiFeO3-0.30PbTiO3 are calculated to be 0.208, -0.061, 0.078 and 0.087 Vm/N, respectively; significantly larger than current military grade devices and previously reported bulk materials. Nb-doping of 0.65BiFeO3-0.35PbTiO3 has been carried out to reduce conductivity. For all doping regimes, the low-signal AC and DC conductivity decreases by up to an order of magnitude. Initially Nb-doping hinders the piezoelectric activity however once annealed, g33 values improve by up to 10 times for some compositions. Impedance spectroscopy, P/x-E loops and X-ray photoelectron spectroscopy show that the piezoelectric behaviour is dictated by the degree of defect distribution, with annealed samples possessing a more distributed defect network and an increase in domain wall mobility. A cooling rate study showed that whilst a more randomly distributed defect structure is achieved compared to unannealed samples, quenching decreases the piezoelectric activity due to the larger intergranular stress when transitioning through the Curie temperature

Human-in-the-last-instance? The concept of “man” between Foucault and Laruelle

Although he has been publishing since the early 1970s, François Laruelle’s project of non-philosophy has only recently received any sustained attention in English-language scholarly work, spurred in large part by the writings of Ray Brassier (along with Alexander Galloway, Katerina Kolozova, John Mullarkey, and Anthony Paul Smith, amongst others). Yet Brassier’s nihilistic anti-humanism has tended to colour this reception in a manner inimical to Laruelle’s stated intentions. The purpose of this article, then, is to focus upon one of the most important, but perhaps also one of the least discussed aspects of Laruelle’s fascinating (if abstruse) non-philosophy: his theory of man, and his claim to have recovered a truly ordinary mode of thought, which he associates with the figure of the One. The task of non-philosophy, Laruelle claims, is not to think about the One (which would be to reduce the human individual to Being), but to think according to the One, whereby the auto-positioned sufficiency of philosophy is suspended, and it is instead understood as occasional material that is determined-in-the-last-instance by the radical immanence of the One, which is not a subject in the philosophical sense, but a living human ‘in flesh and blood’. Over the course of this article, we will examine Laruelle’s (non-)humanist intervention in relation to Michel Foucault’s announcement of the forthcoming ‘death of man’, perhaps the single most notable example of philosophical anti-humanism

The relation of Christianity to Socialism

Thesis (Ph.D.)--Boston Universit

Baby Skyrmions in AdS

We study the baby Skyrme model in a pure AdS background without a mass term. The tail decays and scalings of massless radial solutions are demonstrated to take a similar form to those of the massive flat space model, with the AdS curvature playing a similar role to the flat space pion mass. We also numerically find minimal energy solutions for a range of higher topological charges and find that they form concentric ring-like solutions. Popcorn transitions (named in analogy with studies of toy models of holographic QCD) from an n layer to an n + 1-layer configuration are observed at topological charges 9 and 27 and further popcorn transitions for higher charges are predicted. Finally, a pointparticle approximation for the model is derived and used to successfully predict the ring structures and popcorn transitions for higher charge solitons

Human Papillomavirus Replication Regulation by Acetylation of a Conserved Lysine in the E2 Protein

The papillomavirus (PV) E2 protein is a sequence-specific DNA binding protein that recruits cellular factors to its genome in infected epithelial cells. E2 also binds to and loads the viral E1 DNA helicase at the origin of replication. Posttranslational modifications (PTMs) of PV E2 have been identified as potential regulators of E2 functions. We recently reported lysine 111 (K111) as a target of p300 acetylation in bovine PV (BPV). The di-lysines at 111 and 112 are conserved in almost all papillomaviruses. We pursued a mutational approach to query the functional significance of lysine in human PV (HPV) E2. Amino acid substitutions that prevent acetylation, including arginine, were unable to stimulate transcription and E1-mediated DNA replication. The arginine K111 mutant retained E2 transcriptional repression, nuclear localization, DNA and chromatin binding, and association with E2 binding partners involved in PV transcription and replication. While the replication-defective E2-K111R mutant recruited E1 to the viral replication origin, surprisingly, unwinding of the duplex DNA did not occur. In contrast, the K111 glutamine (K111Q) mutant increased origin melting and stimulated replication compared to wild-type E2. These experiments reveal a novel activity of E2 necessary for denaturing the viral origin that likely depends on acetylation of highly conserved lysine 111.IMPORTANCE HPV is one of the most common sexually transmitted infections in the United States. Over 200 HPVs have been described, and they manifest in a variety of ways; they can be asymptomatic or can result in benign lesions (papillomas) or progress to malignancy. Although 90% of infections are asymptomatic and resolve easily, HPV16 and -18 alone are responsible for 70% of all cervical cancers, which are almost entirely caused by HPV infection. Interestingly, 60 to 90% of other cancers have been linked to HPV. The goal of this research is to further elucidate the mechanisms that regulate and mediate viral replication

SUPERMAN, a regulator of floral homeotic genes in Arabidopsis

We describe a locus, SUPERMAN, mutations in which result in extra stamens developing at the expense of the central carpels in the Arabidopsis thaliana flower. The development of superman flowers, from initial primordium to mature flower, is described by scanning electron microscopy. The development of doubly and triply mutant strains, constructed with superman alleles and previously identified homeotic mutations that cause alterations in floral organ identity, is also described. Essentially additive phenotypes are observed in superman agamous and superman apetala2 double mutants. The epistatic relationships observed between either apetala3 or pistillata and superman alleles suggest that the SUPERMAN gene product could be a regulator of these floral homeotic genes. To test this, the expression patterns of AGAMOUS and APETALA3 were examined in superman flowers. In wild-type flowers, APETALA3 expression is restricted to the second and third whorls where it is required for the specification of petals and stamens. In contrast, in superman flowers, APETALA3 expression expands to include most of the cells that would normally constitute the fourth whorl. This ectopic APETALA3 expression is proposed to be one of the causes of the development of the extra stamens in superman flowers. The spatial pattern of AGAMOUS expression remains unaltered in superman flowers as compared to wild-type flowers. Taken together these data indicate that one of the functions of the wild-type SUPERMAN gene product is to negatively regulate APETALA3 in the fourth whorl of the flower. In addition, superman mutants exhibit a loss of determinacy of the floral meristem, an effect that appears to be mediated by the APETALA3 and PISTILLATA gene products

Tie Me Up!: An Empirical Investigation of Perceived Tie Characteristics on Prospective Connections

How do social networks motivate people to connect not only to their previously existing friends but also to novel or blind new contacts? We report the results of an experiment to identify the value that participants give to alternative network characteristics when deciding to connect to a social network. We focus on network tie characteristics because they represent information that potentially can be automated and provided without compromising privacy policies. Our experiment employed q-methodology to capture participants’ subjective values as they evaluated potential connections described by their tie strength, variety, and quantity, three important tie characteristics. We identify four distinct groups of individuals in terms of value. Our findings suggest social networks should include network characteristics to encourage joining and blind ties. They also suggest that current social network interfaces and research need to be augmented to address network tie characteristics