Regional partnerships to strengthen the seed industry

COLLECTIVE ACTION NEWS is an e-publication of the CGIAR’s Regional Collective Action in Eastern and Southern Afric

Performance of development NGOs in HIV prevention for young people

Includes abstract.Includes bibliographical references.NGO literature is widely dispersed in numerous publications and often laborious to find. This article attempts to enhance understanding of development NGO performance by collating and discussing influencing factors. A systematic review of academic journal articles, published between 1996 and 2008, identified 31 relevant papers. Findings on facilitators and constraints are presented then discussed from a rational choice perspective. The article argues that NGOs are influenced by an intricate web of factors, and puts forward three main standpoints NGOs utilise in making decisions. Depending on one's perspective, NGO action can be interpreted as either rational or irrational behaviour

Design of a mechatronic measurement system for surface fatigue of dental composites

PhD ThesisThis thesis focuses on the design and development of a rolling-ball mechatronic system for on-line testing and measurement of surface contact fatigue of dental composites, and is based on a technique initially developed at the Newcastle Dental School. The mechatronic system synergistically combines the mechanical/electronic hardware with a low-cost embedded digital signal controller (DSC microcontroller) hardware and software to monitor and measure in real-time surface wear due to contact fatigue. ISO/TS 14569-2.2001 standard specification for testing of dental materials was used for selecting appropriate test variables. The mechatronic system attempts to simulate the human oral environment with temperature and moisture being controlled. A closed-loop PI control algorithm combining both optical encoder pulse timing and counting methods is used to drive a dc brushless motor at speeds of 240 and 2040 rpm. A small (2mm diameter) ruby ball is mounted in a V-grooved mandrel which over time creates a circular orbital wear path in the dental composite material. One algorithm has been designed to acquire and process the on-line measurement of wear using a linear voltage differential transformer (LVDT), with another monitoring the fatigue cycling process. A graphical user interface (GUI) has also been designed and implemented on a laptop which is connected to the rig embedded controller. A kinematic model of the rolling ball constrained in a V-groove has been developed along with a finite element analysis of the surface deformation. This has been augmented by a comprehensive test programme, in dry, moisturized and elevated temperature (i.e. 37°C), using Synergy D6 specimens. Using ANOVA test, 70% reproducibility of fatigue track measurements was attained. A comparison of LVDT transducer and profilometer measurements indicated 5% consistence with each other. The insight gained from the testing programme sets a basis for an extensive programme to qualify and validate the measurement system basing on ISO/TS 14569-2.2001 specifications.The Tanzania Government: The University of Dar es Salaam

Full life tables for South Africa from vital registration data, 2006-2008

This research derives a set of full life tables for South Africa as a whole and by population group using vital registration data for the period 2006-2008. Given that not all deaths are registered, the research assesses the level of completeness of death registration for the national population and for all the population groups separately by using the deaths distribution methods

Avoidaee Perinatal Deaths as Seen at Muhimbili National Hospital, Dar-es-Salaam Tanzania.

In developing countries perinatal mortality is still very high and remains a challenge in the care of pregnant women. In a poor resource country like Tanzania knowing the avoidable causes of perinatal deaths can greatly have an impact on perinatal mortality and designing effective and measurable interventions with the available resources. To determine factors contributing to avoidable perinatal death at Muhimbili National Hospital from 1st November 2006 to 31st January 2007. This was a cross sectional descriptive study. All pregnant women admitted in the labour ward and aclampsia ward for delivery during the study period and had perinatal death weight ≥1500gm were included in the study. There were 2628 deliveries during the study period with 192 perinatal death Among them 129 were stillbirths where by 80 were and 49 MSBs. There were 63 first week neonatal deaths. The perinatal mortality rate was 73/1000 births. Stillbirth and early neonatal death rates were 49/1000 births and 24/1000 live births respectively. Twenty five birth weights of <1500gm amd were exclude from the study. The median age of the study population was 26±1.86, where 61.7% (103/…) had primary school education. Most of the women attended their antenatal care at health centre and dispensary level; 77% (129) and 18% (30) at hospital level while 8?..(5%0) women did not attend at all. Suboptimal factors identified in 134 (80.2) mothers who had perinatal deaths 36(21.5%) deaths were possibly avoidable while 57(34.1%) were likely avoidable. To 41(24.6%) mothers the suboptimal factors unlikely contributed to perinatal deaths. Pre-eclampsia/ eclampsia, severe anaemia, malaria and HIV/AIDS were the most common medical conditions observed in mothers who had perinatal deaths. Birth asphyxia and prematurity were the leading causes of deaths. Pre-eclampsia/eclampsia, severe anaemia, malaria, and HIV/AIDS were the common medical conditions that contributed to perinatal deaths. Improving antenatal care at health centers and dispensaries level and intrapartum care at MNH is essential in order to prevent avoidable perinatal deaths

African vegetable diversity in the limelight: project activities by ProNIVA.

Poster presented at Botanical Congress. Hamburg (Germany), 3-7 Sep 200

Effect of within-litter birth weight variation on piglet survival and pre-weaning weight gain in a commercial herd

There are several factors that affect piglet survival and this has a bearing on sow productivity. Ten variables that influence pre-weaning vitality were analysed using records from the Pig Industry Board, Zimbabwe. These included individual piglet birth weight, piglet origin (nursed in original litter or fostered), sex, relative birth weight expressed as standard deviation units, sow parity, total number of piglets born, year and month of farrowing, within-litter variability and the presence of stillborn or mummified littermates. The main factors that influenced piglet mortality were fostering, parity and within-litter variability especially the weight of the individual piglet relative to the average of the litter (P0.05). Presence of a mummified or stillborn littermate, which could be a proxy for unfavourable uterine environment or trauma during the birth process, did not influence pre-weaning mortality. Variability within a litter and the deviation of the weight of an individual piglet from the litter mean, influenced survival to weaning. It is, therefore, advisable for breeders to include uniformity within the litter as a selection criterion. The recording of various variables by farmers seems to be a useful management practice to identify piglets at risk so as to establish palliative measures. Further, farmers should know which litters and which piglets within a litter are at risk and require more attention

Effekte einer Persistierenden Herpesviralen Infektion auf das Adaptive Immunsystem

Herpesviruses are divided into the α, β and γ subfamilies. More than 90% of the human population carries at least one, and more often a combination of several latent herpesviruses. Latency is the ability of a virus to silently persist in the host, and to reactivate upon episodes of immune suppression. During latency, the immune system is weakly, but persistently stimulated by viral antigens, and the effects of such burden on the homeostasis and function of the immune system remain unclear. To address this question, mice were infected with α, β or γ herpesviruses, individually or in combinations. There were no obvious changes in the homeostasis of the B cells, but an irreversible and very large increase of activated CD8 T cells, especially in mice carrying latent mouse cytomegalovirus (MCMV), a β herpesvirus. To investigate if this change led to functional impairments of the immune response to a new infection, the latently infected mice were challenged with vesicular stomatitis virus (VSV). At day 7 or 14 post challenge, the number of CD8 T cells responding to a VSV antigen were not altered, but due to the huge increase in the size of the CD8 compartment, the fraction of VSV-responding cells was reduced in the blood (but not in lymphatic organs) of mice carrying latent MCMV. Latent herpesviruses did not affect the VSV responses in the CD4 T cell compartment, but there was a delay in the Immunoglobulin (Ig) class-switch in MCMV infected mice. In conclusion, infection with persistent herpesviruses resulted in permanent changes in the homeostasis but not the function of the T cells and in delayed Ig class-switch in MCMV infected mice. Due to the pervasiveness of latent herpesvirus infections, these results may have important implications for public health, but also for the design of CMV-based vaccines.Herpesviren werden in die α-, β- und γ-Unterfamilie eingeteilt. Mehr als 90% der Be-völkerung sind mit einem oder mehreren Herpesviren latent infiziert. Latenz ist die Fähigkeit viraler Genome stumm im Wirt zu persistieren und bei Immunsuppression zu reaktivieren. In der Latenz wird das Immunsystem schwach aber kontinuierlich durch vi-rale Antigene stimuliert. Der Effekt dieser Stimulation auf Homöostase und Funktion des Immunsystems ist unklar. Um dies zu untersuchen, wurden Mäuse mit α-, β- und γ-Herpesviren infiziert, einzeln und in Kombination. Man konnte keine offensichtliche Veränderung in der B-Zellpopulation feststellen. Allerdings kam es zu einem starken, irreversiblen Anstieg aktivierter CD8+ T-Zellen, vor allem in Tieren die latent mit dem murinen Zytomegalievirus (MCMV; β-Herpesvirus) infiziert waren. Um zu untersuchen, ob dies zu einer funktionellen Einschränkung der Immunantwort auf eine neue Infektion führt, wurden die latent infizierten Mäuse mit Vesicular stomatitis virus (VSV) infiziert. An Tag 7 und 14 nach Infektion war die Zahl der VSV-spezifischen CD8+ T-Zellen nicht verändert, der prozentuale Anteil im Blut (jedoch nicht in lymphatischen Organen) war hingegen stark reduziert, was an der Vergrößerung der CD8+ T-Zellpopulation in latent MCMV infizierten Tieren liegt. Latente Herpesviren hatten keinen Einfluss auf die CD4+ T-Zellantwort gegen VSV, allerdings zeigte sich eine Verzögerung des Immunglobulin (Ig) class-switch in MCMV infizierten Mäusen. Abschließend kann man sagen, dass die Infektion mit persistenten Herpesviren zu permanenten Veränderungen der T-Zell-homöostase, nicht jedoch der T-Zellfunktion, sowie zu einem verzögerten Ig-class-switch in MCMV infizierten Mäusen führt. Aufgrund der weiten Verbreitung latenter Her-pesinfektionen haben diese Ergebnisse bedeutende Auswirkungen auf das öffentliche Gesundheitswesen, aber auch für die Entwicklung CMV-basierter Impfstoffe