Evaluation of Selected Pigeonpea (Cajanus cajan (L.) Millsp.) Genotypes for Resistance to Insect Pest Complex in Dry Areas of North Rift Valley, Kenya

Pigeonpea is an important pulse crop that has gained importance in semi-arid tropics, although its yield potential has not been fully realized due to biotic and abiotic stresses that limit its production. Insect pest complex of pod borer (Helicoverpa armigera), sucking bug (Clavigralla tomentosicollis) and pod fly (Melanagromyza cholcosoma) are the major limiting factors to its production causing up to 100% yield loss. The objective of this study was to evaluate resistant genotypes to insect pest complex in dry parts of North Rift Valley Kenya. The study was carried out in three sites (Kenya Agricultural Livestock Research Organization- Marigat, Agricultural Training Centre-Koibatek and Fluorspar-Chepsirei) for one season during long rain of April-November 2014 growing season. Sixteen ICRISAT elite genotypes were evaluated in randomized complete block design (RCBD) with 75cm inter and 25 cm intra spacing. Significant (P≤0.05) differences in grain yield performance, incidence and severity of the insect pests were revealed in all sites. The damage was more severe in Marigat (Pod borer-37.2%, Sucking bug-39.3% and pod fly-5.9%) than ATC- Koibatek (Pod borer-1.9%, Sucking bug-8.4% and pod fly-5.9%) and Fluorspar (Pod borer-3.6%, Sucking bug-6.8% and pod fly-2.9%). Genotypes ICEAPs 00850R, 00902, 01541 and 1154-2 showed potential levels of resistance to the insect pest complex and high yields. Grain yield associated negatively (P≤0.05) with pod borer and sucking bug damage correlated non-significantly with pod fly damage. The potential genotypes identified in this study need to be further evaluated in two seasons and in other multi-locations to validate these findings to be used in breeding

CXCR4/CXCL12 Participate in Extravasation of Metastasizing Breast Cancer Cells within the Liver in a Rat Model

INTRODUCTION: Organ-specific composition of extracellular matrix proteins (ECM) is a determinant of metastatic host organ involvement. The chemokine CXCL12 and its receptor CXCR4 play important roles in the colonization of human breast cancer cells to their metastatic target organs. In this study, we investigated the effects of chemokine stimulation on adhesion and migration of different human breast cancer cell lines in vivo and in vitro with particular focus on the liver as a major metastatic site in breast cancer. METHODS: Time lapse microscopy, in vitro adhesion and migration assays were performed under CXCL12 stimulation. Activation of small GTPases showed chemokine receptor signalling dependence from ECM components. The initial events of hepatic colonisation of MDA-MB-231 and MDA-MB-468 cells were investigated by intravital microscopy of the liver in a rat model and under shRNA inhibition of CXCR4. RESULTS: In vitro, stimulation with CXCL12 induced increased chemotactic cell motility (p,0.05). This effect was dependent on adhesive substrates (type I collagen, fibronectin and laminin) and induced different responses in small GTPases, such as RhoA and Rac-1 activation, and changes in cell morphology. In addition, binding to various ECM components caused redistribution of chemokine receptors at tumour cell surfaces. In vivo, blocking CXCR4 decreased extravasation of highly metastatic MDA-MB-231 cells (p < 0.05), but initial cell adhesion within the liver sinusoids was not affected. In contrast, the less metastatic MDA-MB-468 cells showed reduced cell adhesion but similar migration within the hepatic microcirculation. CONCLUSION: Chemokine-induced extravasation of breast cancer cells along specific ECM components appears to be an important regulator but not a rate-limiting factor of their metastatic organ colonization.Claudia Wendel, André Hemping-Bovenkerk, Julia Krasnyanska, Sören Torge Mees, Marina Kochetkova, Sandra Stoeppeler and Jörg Haie

Estimating the Number of Paediatric Fevers Associated with Malaria Infection Presenting to Africa's Public Health Sector in 2007

Peter Gething and colleagues compute the number of fevers likely to present to public health facilities in Africa and the estimated number of these fevers likely to be infected with Plasmodium falciparum malaria parasites

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd

Building Knowledge-Based Economies in Africa: A Systematic Review of Policies and Strategies

Compared to other regions of the world, Africa is lagging in its drive toward knowledge-based economies. This study systematically reviews the literature in order to highlight the policies and strategies with which African countries can accelerate their current drive towards building knowledge-based economies. These are discussed in terms of three pillars of the World Bank’s knowledge economy framework. They are the indices for: (i) education and skilled population, (ii) information and communication technology and (iii) economic incentives and institutional regime