Trends in Kenya agriculture in relation to employment

The objectives of this paper are to contribute to an understanding of the nature of the unemployment problem in Kenya through analysis of trends in agricultural employment in the various sub-sectors of agriculture, and secondly, on the basis of this analysis, to consider policy alternatives aimed at increasing job opportunities in agriculture. The first section describes the major movements of people that have been occurring within agriculture, and emphasises the importance of education investment in explaining movements out of agriculture. Then the differential effects of farm technology on employment in small scale and estate agriculture are compared, and the effects of changing farm structure on employment in the large mixed farming areas examined. Lastly, policy possibilities are discussed

East Africa and three international commodity agreements : the lessons of experience

East Africa relies heavily on the export of agricultural commodities for foreign exchange. Three of East Africa's most important agricultural exports have been subject to quotas under international commodity agreements: the International Coffee Agreement, the informal sisal agreement, and the informal tea agreement. This, paper focuses on a hitherto neglected aspect of their wordings: the distribution of gains from membership among exporting countries. In reviewing the major developments under each agreement, the value of commodity agreements to East African countries is questioned. Particular attention is given to the determination of export shares, which are shown to be difficult to change once allocated. The need to take account of employment effects as well as possible income gains in calculating costs/ benefits of membership of commodity agreements is emphasised

The Outcome of Neutrophil-T Cell Contact Differs Depending on Activation Status of Both Cell Types

Neutrophils and T cells exist in close proximity in lymph nodes and inflamed tissues duringhealth and disease. They are able to form stable interactions, with profound effects on thephenotype and function of the T cells. However, the outcome of these effects arefrequently contradictory; in some systems neutrophils suppress T cell proliferation, inothers they are activatory or present antigen directly. Published protocols modelling theseinteractions in vitro do not reflect the full range of interactions found in vivo; they do notexamine how activated and naïve T cells differentially respond to neutrophils, or whetherde-granulating or resting neutrophils induce different outcomes. Here, we established aculture protocol to ask these questions with human T cells and autologous neutrophils.We find that resting neutrophils suppress T cell proliferation, activation and cytokineproduction but that de-granulating neutrophils do not, and neutrophil-releasedintracellular contents enhance proliferation. Strikingly, we also demonstrate that T cellsearly in the activation process are susceptible to suppression by neutrophils, while laterstage T cells are not, and naïve T cells do not respond at all. Our protocol therefore allowsnuanced analysis of the outcome of interaction of these cells and may explain thecontradictory results observed previously

Integrated systems for rapid point of care (PoC) blood cell analysis

Counting the different subpopulations of cells in a fingerprick of human blood is important for a number of clinical point-of-care (PoC) applications. It is a challenge to demonstrate the integration of sample preparation and detection techniques in a single platform. In this paper we demonstrate a generic microfluidic platform that combines sample processing and characterisation and enumeration in a single, integrated system. Results of microfluidic 3-part differential leukocyte (granulocyte, lymphocyte and monocyte) counts, together with erythrocyte and thrombocyte (platelet) counts, in human blood are shown and corroborated with results from hospital clinical laboratory analysis

IFN-γ-producing CD4+ T cells promote experimental cerebral malaria by modulating CD8+ T cell accumulation within the brain.

It is well established that IFN-γ is required for the development of experimental cerebral malaria (ECM) during Plasmodium berghei ANKA infection of C57BL/6 mice. However, the temporal and tissue-specific cellular sources of IFN-γ during P. berghei ANKA infection have not been investigated, and it is not known whether IFN-γ production by a single cell type in isolation can induce cerebral pathology. In this study, using IFN-γ reporter mice, we show that NK cells dominate the IFN-γ response during the early stages of infection in the brain, but not in the spleen, before being replaced by CD4(+) and CD8(+) T cells. Importantly, we demonstrate that IFN-γ-producing CD4(+) T cells, but not innate or CD8(+) T cells, can promote the development of ECM in normally resistant IFN-γ(-/-) mice infected with P. berghei ANKA. Adoptively transferred wild-type CD4(+) T cells accumulate within the spleen, lung, and brain of IFN-γ(-/-) mice and induce ECM through active IFN-γ secretion, which increases the accumulation of endogenous IFN-γ(-/-) CD8(+) T cells within the brain. Depletion of endogenous IFN-γ(-/-) CD8(+) T cells abrogates the ability of wild-type CD4(+) T cells to promote ECM. Finally, we show that IFN-γ production, specifically by CD4(+) T cells, is sufficient to induce expression of CXCL9 and CXCL10 within the brain, providing a mechanistic basis for the enhanced CD8(+) T cell accumulation. To our knowledge, these observations demonstrate, for the first time, the importance of and pathways by which IFN-γ-producing CD4(+) T cells promote the development of ECM during P. berghei ANKA infection

The relationship between redox enzyme activity and electrochemical potential—cellular and mechanistic implications from protein film electrochemistry

In protein film electrochemistry a redox protein of interest is studied as an electroactive film adsorbed on an electrode surface. For redox enzymes this configuration allows quantification of the relationship between catalytic activity and electrochemical potential. Considered as a function of enzyme environment, i.e., pH, substrate concentration etc., the activity–potential relationship provides a fingerprint of activity unique to a given enzyme. Here we consider the nature of the activity–potential relationship in terms of both its cellular impact and its origin in the structure and catalytic mechanism of the enzyme. We propose that the activity–potential relationship of a redox enzyme is tuned to facilitate cellular function and highlight opportunities to test this hypothesis through computational, structural, biochemical and cellular studies

Chinese Script vs Plate-Like Precipitation of Beta-Al9Fe2Si2 Phase in an Al-6.5Si-1Fe Alloy

The microstructure of a high-purity Al-6.5Si-1Fe(wt pct) alloy after solidification at various cooling rates was investigated. In most of the cases, the monoclinic beta-Al9Fe2Si2 phase was observed as long and thin lamellae. However, at a very slow cooling rate, Febearing precipitates with Chinese script morphology appeared together with lamellae. Further analysis showed all these Chinese script precipitates correspond also to the monoclinic beta phase. This finding stresses that differentiating second phases according to their shape may be misleading

Cathelicidin is a “fire alarm”, generating protective NLRP3-dependent airway epithelial cell inflammatory responses during infection with Pseudomonas aeruginosa

<div><p>Pulmonary infections are a major global cause of morbidity, exacerbated by an increasing threat from antibiotic-resistant pathogens. In this context, therapeutic interventions aimed at protectively modulating host responses, to enhance defence against infection, take on ever greater significance. <i>Pseudomonas aeruginosa</i> is an important multidrug-resistant, opportunistic respiratory pathogen, the clearance of which can be enhanced <i>in vivo</i> by the innate immune modulatory properties of antimicrobial host defence peptides from the cathelicidin family, including human LL-37. Initially described primarily as bactericidal agents, cathelicidins are now recognised as multifunctional antimicrobial immunomodulators, modifying host responses to pathogens, but the key mechanisms involved in these protective functions are not yet defined. We demonstrate that <i>P</i>. <i>aeruginosa</i> infection of airway epithelial cells promotes extensive infected cell internalisation of LL-37, in a manner that is dependent upon epithelial cell interaction with live bacteria, but does not require bacterial Type 3 Secretion System (T3SS). Internalised LL-37 acts as a second signal to induce inflammasome activation in airway epithelial cells, which, in contrast to myeloid cells, are relatively unresponsive to <i>P</i>. <i>aeruginosa</i>. We demonstrate that this is mechanistically dependent upon cathepsin B release, and NLRP3-dependent activation of caspase 1. These result in LL-37-mediated release of IL-1β and IL-18 in a manner that is synergistic with <i>P</i>. <i>aeruginosa</i> infection, and can induce caspase 1-dependent death of infected epithelial cells, and promote neutrophil chemotaxis. We propose that cathelicidin can therefore act as a second signal, required by <i>P</i>. <i>aeruginosa</i> infected epithelial cells to promote an inflammasome-mediated altruistic cell death of infection-compromised epithelial cells and act as a “fire alarm” to enhance rapid escalation of protective inflammatory responses to an uncontrolled infection. Understanding this novel modulatory role for cathelicidins, has the potential to inform development of novel therapeutic strategies to antibiotic-resistant pathogens, harnessing innate immunity as a complementation or alternative to current interventions.</p></div