Direct Electrochemical Regeneration of NADH on Au, Cu and Pt-Au Electrodes

The regeneration of a reduced form of nicotinamide adenine dinucleotide (NADH) in a batch electrochemical reactor employing Au, Cu and Pt-Au electrodes was investigated. The yield of enzymatically active NADH regenerated was found to depend on the electrolysis potential and the electrode material used. At low negative potentials the yield of active NADH regenerated is similar on both Au and Cu, and relatively high (75 % and 71 %, respectively), but the NAD+ reduction rate and the corresponding conversion degree is low. At high (industrially relevant) negative potentials the NAD+ reduction rate and the corresponding conversion degree is high, while the yield of active NADH formed on Au is low (28 %) and intermediate on Cu (52 %). In order to increase the yield of enzymatically active NADH formed at high (industrially relevant) potentials, the Au surface was modified with Pt. This resulted in an increase in the yield of active NADH from 29.6 % to 63 %. A reaction mechanism taking into account the influence of Pt is proposed

Impact of foot-and-mouth disease on mastitis and culling on a large-scale dairy farm in Kenya

Foot and mouth disease (FMD) is a highly transmissible viral infection of cloven hooved animals associated with severe economic losses when introduced into FMD-free countries. Information on the impact of the disease in FMDV-endemic countries is poorly characterised yet essential for the prioritisation of scarce resources for disease control programmes. A FMD (virus serotype SAT2) outbreak on a large-scale dairy farm in Nakuru County, Kenya provided an opportunity to evaluate the impact of FMD on clinical mastitis and culling rate. A cohort approach followed animals over a 12-month period after the commencement of the outbreak. For culling, all animals were included; for mastitis, those over 18 months of age. FMD was recorded in 400/644 cattle over a 29-day period. During the follow-up period 76 animals were culled or died whilst in the over 18 month old cohort 63 developed clinical mastitis. Hazard ratios (HR) were generated using Cox regression accounting for non-proportional hazards by inclusion of time-varying effects. Univariable analysis showed FMD cases were culled sooner but there was no effect on clinical mastitis. After adjusting for possible confounders and inclusion of time-varying effects there was weak evidence to support an effect of FMD on culling (HR = 1.7, 95% confidence intervals [CI] 0.88-3.1, P = 0.12). For mastitis, there was stronger evidence of an increased rate in the first month after the onset of the outbreak (HR = 2.9, 95%CI 0.97-8.9, P = 0.057)

Gadolinium and nephrogenic systemic fibrosis: time to tighten practice

Nephrogenic systemic fibrosis (NSF) is a relatively new entity, first described in 1997. Few cases have been reported, but the disease has high morbidity and mortality. To date it has been seen exclusively in patients with renal dysfunction. There is an emerging link with intravenous injection of gadolinium contrast agents, which has been suggested as a main triggering factor, with a lag time of days to weeks. Risk factors include the severity of renal impairment, major surgery, vascular events and other proinflammatory conditions. There is no reason to believe that children have an altered risk compared to the adult population. It is important that the paediatric radiologist acknowledges emerging information on NSF but at the same time considers the risk:benefit ratio prior to embarking on alternative investigations, as children with chronic kidney disease require high-quality diagnostic imaging

Practical locality-awareness for large scale information sharing

Tulip is an overlay for routing, searching and publish-lookup information sharing. It offers a unique combination of the advantages of both structured and unstructured overlays, that does not co-exist in any previous solution. Tulip features locality awareness (stretch 2) and fault tolerance (nodes can route around failures). It supports under the same roof exact keyed-lookup, nearest, copy location, and global information search. Tulip has been deployed and its locality and fault tolerance properties verified over a real wide-area network

Production of marketable milk in the sub-humid tropics: experiences, lessons and technologies from coastal Kenya

The Kenya coastal region has a large, unsatisfied market for milk and dairy products. Between 1988 and 1994, a research project, closely linked to extension, identified and addressed technical constraints that limit smallholder dairy Development in the region. Methodological approaches are outlined. Smallholders found it difficulty to maintain the advantages of systematic crossbreeding. Research showed that rotational crossing was appropriate when AI is available. In its absence, crossbred bulls should be considered. A study of lifetime productivity demonstrated the major contribution that genetic improvement can make to increasing productivity. Systematic epidemiological studies identified East Coast fever (ECF) as the cause of serious production losses. The infection and treatment method of immunization was more effective than current control methods, and was accepted by smallholders. Compared to recommended practises, intercropping with legumes, and manure and legume mulch application, improved year - round feed availability for dairy cows. Feeding legume and maize bran supplements was very cost-effective. Through collaborative research-extension activities, legume technologies were extended to many smallholdings. The linkages with farmers will facilitate the Development and testing of other technologies. Finally, the importance of a favourable operational environment for smallholders is emphasised, including institutional structures to encourage effective research- extension- farmer linkages and policies to facilitate dairy market Development

ISSR-BASED MOLECULAR CHARACTERIZATION OF TRITICUM EASTIVUM L. CULTIVARS

Abstract: Molecular genetic markers are widely used tools in genotype and species identification. Genetic relationship study was performed with 20 ISSR primers among 12 Indian wheat accessions (6 salt tolerant and 6 salt susceptible). Genomic DNA from wheat genotypes were analyzed using inter simple sequence repeats (ISSR) markers. Thirteen ISSR primers produced 78 amplified DNA fragments ranging in size from 100-2200 base pairs, 6 fragments were monomorphic (7.7%) and 72 fragments were polymorphic (92.3%) with an average of 6 fragments per primer and 5.53 polymorphic fragments per primer. Six primers were found to be highly informative as they gave unique bands to differentiate between salt susceptible and salt tolerant genotypes. From ISSR profiles similarity matrix was obtained and Jaccard's similarity coefficient was observed in between 0.40 to 0.77 and on this basis a dendogram was constructed with UPGMA method. Easy handling, high information levels and reliability are the features that justify the utility of ISSR markers in DNA fingerprinting and genetic variability analysis which is highly useful for finding genes controlling agronomically important traits in whea

Research on smallholder dairy production in coastal lowland Kenya

This paper describes the origins and subsequent development of a collaborative programme of research on smallholder dairy production between KARI, ILCA and other cooperating institutions. The programme conducted research within a farming ystems framework in per-urban areas of coastal lowland Kenya. The integrated programme of on-farm and on-station research covers farming systems description and constraint identification, and technology development and testing. Major research areas centre on studies of milk consumption and marketing, smallholder resource management, disease risk to dairy cattle, feeding systems development and dairy cattle breeding. Results to date have confirmed the large milk deficit. East Coast fever has been shown to cause major losses in smallholder dairy cattle. The seasonal feed shortages and inadequate nutrient concentrations in milk produciton diets are being adressed through integrating crops and livestock by intercropping fodder grasses, maize and cassava with shrub and herbaceous legumes and the application of cattle manure. Rotational crossbreeding has been shown to be an efficient breeding system for smallholder milk production. Studies of current farming systems and the assessment of resource levels indicate that for the majority of households, agricultural change will be a sequential intensificaiton through the adoption of individual technological components rather than through the adoption of a multi-component package, such as the National Dairy Development Project's zero-grazing package