Performance trials on different rates and ratios of N and P fertilisation in Ethiopia to inform field-specific Maize-Nutrient-Management advisory

This report of the Scaling Readiness of Nutrient Management decision Support Tools project focuses on agronomic trials that serve to inform the development of scalable, field-specific advisory for maize farmers in Ethiopia. These trials were conducted to generate additional information required to make a mobile phone-based nutrient decision support tool – Maize-Nutrient-Manager – more scalable in the context of institutional limitations in fertilizer availability and distribution in Ethiopia. The focus of the trials is on establishing proper N:P ratio’s for different fertilization rates with the fertilizers available to farmers in West-Shewa and Jimma (two major maize belts in Ethiopia). The trials were conducted with additional funding from the TAMASA project and in collaboration with EIAR. As the latter institute is involved in conducting fertilizer trials and the development of recommendations, this collaboration also aimed at forming an appropriate entry point for institutionalization of the decision support tool that is being developed

Maize-Nutrient-Manager: A mobile phone application for field-specific, balanced nutrient management advisory

To increase productivity and profitability, while limiting nutrient losses and related GHG-emissions, African smallholders need more tailored fertilizer advice. Yet, such advice critically hinges upon – largely lacking – field-level management data, as management is key to efficient fertilizer use. The Maize- Nutrient-Manager (MNM) mobile phone application enables collection of such data at scale, and directly converts this data into actionable advice for the farmer. Focusing on field-level management data, MNM can identify those management practices that are currently imperative for enhancing smallholder farmers’ efficient use of fertilizers in their locality, thereby increasing productivity while reducing greenhouse gas (GHG) emissions. This document describes the background, design principles and development process of then MNM mobile phone application, as well as its pilot use in advisory practice in the Mbozi and Momba districts of Songwe region, Tanzania

QoS in Today's Internet

To be able to guarantee service quality end-to-end Quality of Service has to be deployed. This thesis addresses the problems with applying QoS end-to-end over today’s Internet. A rather pessimistic conclusion states that QoS over Internet is hard (impossible?) to realize without introducing virtual circuits or similar. The concept of flows and label switching is introduced. Some QoS techniques are presented

Analytic Model for Cross-Layer Dependencies in VDSL2 access networks

Recent changes in user employment of Internet based services, new deployment technologies for mobile networks as well as an ongoing realisation of fixed and mobile converged networks e.g. the EU FP7 project COMBO, are significant examples of enablers for increasing demands on DSL links. Investigating cross-layer dependencies between all layers in the OSI reference model becomes increasingly important. In this paper we present an analytical model and experimental results for the relation between impulse noise on a VDSL2 link and the effect this have on the network layer packet loss. We show how the packet loss rate is dependent not only on the disturbance signal level and periodicity but also on the link utilisation

Time-stamping accuracy in virtualized environments

The swift acceptance and the widespread use of virtual environments has substantially increased the stress on networks as each of the operating systems running in parallel sends out packets over the same network. As an increased number of packets traverse a network, the importance to continuously monitor whether the network is providing satisfactory service has increased. The metrics for such analyses includes delay, jitter, packet loss and available path capacity. The basic parameter required to quantify these metrics is the timestamping values of the packets. The purpose of this research work is to characterize the impact of virtualization on a PC's time-stamping process. Operating system virtualization is employed where the time-stamping is done by the operating system kernel. CPU load and packet generating parameters are varied in order to study about the effect of virtualization on the time-stamping process under different operating conditions

Efficient four fragment cloning for the construction of vectors for targeted gene replacement in filamentous fungi

<p>Abstract</p> <p>Background</p> <p>The rapid increase in whole genome fungal sequence information allows large scale functional analyses of target genes. Efficient transformation methods to obtain site-directed gene replacement, targeted over-expression by promoter replacement, in-frame epitope tagging or fusion of coding sequences with fluorescent markers such as GFP are essential for this process. Construction of vectors for these experiments depends on the directional cloning of two homologous recombination sequences on each side of a selection marker gene.</p> <p>Results</p> <p>Here, we present a USER Friendly cloning based technique that allows single step cloning of the two required homologous recombination sequences into different sites of a recipient vector. The advantages are: A simple experimental design, free choice of target sequence, few procedures and user convenience. The vectors are intented for <it>Agrobacterium tumefaciens </it>and protoplast based transformation technologies. The system has been tested by the construction of vectors for targeted replacement of 17 genes and overexpression of 12 genes in <it>Fusarium graminearum</it>. The results show that four fragment vectors can be constructed in a single cloning step with an average efficiency of 84% for gene replacement and 80% for targeted overexpression.</p> <p>Conclusion</p> <p>The new vectors designed for USER Friendly cloning provided a fast reliable method to construct vectors for targeted gene manipulations in fungi.</p