Improving aflatoxin control in Haiti (AFLAH)

The AFLAH project designed and tested strategies for disseminating and promoting effective aflatoxin control methods among women and men stakeholders in the peanut value chain, and supported public institutions in ensuring the safety of peanuts and their by-products. Although pre- and post-harvest technologies for aflatoxin control (such as the use of tarpaulins and the sorting of contaminated kernels and grains) are well known, the factors that influence the adoption of these methods need thorough investigation. Aflatoxins are various poisonous carcinogens and mutagens that are produced by certain molds. When contaminated food is processed or consumed, the aflatoxins enter the general food supply. This detailed document is in English and French, including Annex reports and resources

Analysis of the IEC 61850 protocol when used for communication during maintenance operations in an electrical substation grid

Abstract: During Substation maintenance a bay is taken out of service, tested and during testing traffic is generated on the Substation Communication Network (SCN) in a power utility. A model of a Substation Communication Network that is using the International Electrotechnical Commission (IEC) 61850 protocol has been modeled in Optimized Network Engineering Tool (OPNET). IEC 61850 is a protocol that can be used in a power utility to provide interoperability between different vendors of Intelligent Electronic Devices (IED’s). Most of the IED’s sold by manufacturers for power utility networks support IEC 61850 protocol. The model has three scenarios and they are normal operation of a Substation, maintenance in a Substation and Buszone operation at a Substation. In all the scenarios packet end to end delay of GOOSE, GSSE, SV and MMS messages are monitored. The throughput from the IED under maintenance and the throughput at the Substation RTU end is monitored in the Model. The design of the Substation Communication Network using IEC 61850 will assist when trying to predict the behavior of the network with regards to this specific protocol during maintenance and when there are faults in the communication network or IED’s

Modelling the IEC 61850 and DNP3 Protocol Using OPNET in an Electrical Substation Communication Network

Communication protocols are a composite of supervisory control and data acquisition (SCADA) and they are used by the devices connected on the SCADA network. In this paper the distributed network protocol (DNP3) and International Electrotechnical Commission IEC 61850 communication protocols were modelled in OPNET. The simulation of DNP3 and IEC 61850 communication protocol is done in different scenarios and the traffic behavior is analyzed. The DNP3 protocol is modelled as the medium protocol of communication during the maintenance of a 400kV Transformer at an Electrical Substation. Its network traffic behavior is then analyzed for this operation. The IEC 61850 protocol is then used as a medium of communication in the same Electrical Substation communication network (SCN) when a faulty backbone switch is present. In this scenario the network traffic behavior is again analyzed. The DNP3 simulation during the maintenance of the 400 kV Transformer shows that the model is working since the throughput is consistent without dropped packets at the Substation RTU end and the 400kV Transformer IED end. The IEC 61850 simulation when a faulty backbone switch is present shows that the model is working in this scenario since the throughput is again consistent. When the IEC 61850 protocol is modelled on the SCN, the time delay is 80 μs during normal operation and with a faulty switch the delay is 100 μs for this protocol. This shows that for the IEC 61850 model the time delay increases when there is a faulty backbone switch but not exceedingly since there is a backup switch in the structure. In the DNP3 model during the maintenance of the 400kV Transformer the time delay is approximately 160 μs. The IEC 61850 protocol performs approximately twice as fast as the DNP3 protocol during normal operation in an SCN.University of South AfricaElectrical and Mining Engineerin

Packet Analysis of DNP3 protocol over TCP/IP at an Electrical Substation Grid modelled in OPNET

In this paper Intelligent Electronic Devices (IED) that use ethernet for communicating with substation devices on the grid where modelled in OPNET. There is a need to test the communication protocol performance over the network. A model for the substation communication network was implemented in OPNET. This was done for ESKOM, which is the electrical power generation and distribution authority in South Africa. The substation communication model consists of 10 ethernet nodes which simulate protection Intelligent Electronic Devices (IEDs), 13 ethernet switches, a server which simulates the substation Remote Terminal Unit (RTU) and the DNP3 Protocol over TCP/IP simulated on the model. DNP3 is a protocol that can be used in a power utility computer network to provide communication service for the grid components. It was selected as the communication protocol because it is widely used in the energy sector in South Africa. The network load and packet delay parameters were sampled when 10%, 50%, 90% and 100% of devices are online. Analysis of the results showed that with an increase in number of nodes there was an increase in packet delay as well as the network load. The load on the network should be taken into consideration when designing a substation communication network that requires a quick response such as a smart gird.University of South AfricaElectrical and Mining Engineerin

Strategy Precedes Operational Effectiveness: Aligning High Graduation Rankings With Competitive Graduation Grade Point Averages

Two pivotal and interconnected claims are addressed in this article. First, strategy precedes program effectiveness. Second, graduation rates and rankings are insufficient in any account of academic progress for African American students. In this article, graduation is regarded as the floor and not the ceiling, as it were. The ideal situation in the promotion of strategy is the alignment of high graduation rates or rankings with high graduation cumulative grade point averages. This strategic alignment is precisely what needs to be formulated in the first instance before making judgments about program development and/or operational effectiveness. The work of the Office of African American Affairs of the University of Virginia provides the context for observing trends in academic performance that illustrate the optimal alignment between high graduation rankings and correspondingly high grade point averages

State of Knowledge of Soil Biodiversity: Status, Challenges, and Potentialities

This report presents the threats to soil biodiversity and the solutions that soil biodiversity can provide to problems in different fields, including agriculture, environmental conservation, climate change adaptation and mitigation, nutrition, medicine and pharmaceuticals, remediation of polluted sites, and many others. There is increasing attention on the importance of biodiversity for food security and nutrition, especially above-ground biodiversity such as plants and animals. Less attention is being paid to the biodiversity beneath our feet: soil biodiversity. Yet the rich diversity of soil organisms drives many processes that produce food, regenerate soil or purify water. This report is the result of an inclusive process involving more than 300 scientists from around the world under the auspices of FAO's Global Soil Partnership and its Intergovernmental Technical Panel on Soils, the Convention on Biological Diversity, the Global Soil Biodiversity Initiative, and the European Commission

La qualité de vie des citoyens à Alma : résultats de l'enquête de 1998

Cette enquête sur la qualité de vie des citoyens de la municipalité d'Alma s'inscrit dans le projet de « modélisation du suivi des impacts sociaux de l'aluminerie d'Alma ». La première étape de ce projet de recherche longitudinale et mulîimodale consiste à faire le portrait de référence1 d'Alma et de sa région d'appartenance avant la construction de la nouvelle usine. L'enquête sur la qualité de vie des Almatois s'inscrit dans ce projet, se voulant une première mesure des perceptions des citoyens par rapport à ce qui constitue l'essentiel de leur qualité de vie. Elle a été conçue sur le mode longitudinal, pour être répétée dans l'avenir, ce qui permettra de faire le suivi dans l'évolution des perceptions et la mesure de la réalisation des attentes des répondants sur une période de cinq ans, soit avant, pendant et après la construction de la nouvelle usine

HIV-1 Residual Viremia Correlates with Persistent T-Cell Activation in Poor Immunological Responders to Combination Antiretroviral Therapy

BACKGROUND:The clinical significance and cellular sources of residual human immunodeficiency virus type 1 (HIV-1) production despite suppressive combination antiretroviral therapy (cART) remain unclear and the effect of low-level viremia on T-cell homeostasis is still debated. METHODOLOGY/PRINCIPAL FINDINGS:We characterized the recently produced residual viruses in the plasma and short-lived blood monocytes of 23 patients with various immunological responses to sustained suppressive cART. We quantified the residual HIV-1 in the plasma below 50 copies/ml, and in the CD14(high) CD16(-) and CD16+ monocyte subsets sorted by flow cytometry, and predicted coreceptor usage by genotyping V3 env sequences. We detected residual viremia in the plasma of 8 of 10 patients with poor CD4+ T-cell reconstitution in response to cART and in only 5 of 13 patients with good CD4+ T-cell reconstitution. CXCR4-using viruses were frequent among the recently produced viruses in the plasma and in the main CD14(high) CD16(-) monocyte subset. Finally, the residual viremia was correlated with persistent CD4+ and CD8+ T-cell activation in patients with poor immune reconstitution. CONCLUSIONS:Low-level viremia could result from the release of archived viruses from cellular reservoirs and/or from ongoing virus replication in some patients. The compartmentalization of the viruses between the plasma and the blood monocytes suggests at least two origins of residual virus production during effective cART. CXCR4-using viruses might be produced preferentially in patients on cART. Our results also suggest that low-level HIV-1 production in some patients may contribute to persistent immune dysfunction despite cART