Genomic and experimental evidence for multiple metabolic functions in the RidA/YjgF/YER057c/UK114 (Rid) protein family.

BackgroundIt is now recognized that enzymatic or chemical side-reactions can convert normal metabolites to useless or toxic ones and that a suite of enzymes exists to mitigate such metabolite damage. Examples are the reactive imine/enamine intermediates produced by threonine dehydratase, which damage the pyridoxal 5'-phosphate cofactor of various enzymes causing inactivation. This damage is pre-empted by RidA proteins, which hydrolyze the imines before they do harm. RidA proteins belong to the YjgF/YER057c/UK114 family (here renamed the Rid family). Most other members of this diverse and ubiquitous family lack defined functions.ResultsPhylogenetic analysis divided the Rid family into a widely distributed, apparently archetypal RidA subfamily and seven other subfamilies (Rid1 to Rid7) that are largely confined to bacteria and often co-occur in the same organism with RidA and each other. The Rid1 to Rid3 subfamilies, but not the Rid4 to Rid7 subfamilies, have a conserved arginine residue that, in RidA proteins, is essential for imine-hydrolyzing activity. Analysis of the chromosomal context of bacterial RidA genes revealed clustering with genes for threonine dehydratase and other pyridoxal 5'-phosphate-dependent enzymes, which fits with the known RidA imine hydrolase activity. Clustering was also evident between Rid family genes and genes specifying FAD-dependent amine oxidases or enzymes of carbamoyl phosphate metabolism. Biochemical assays showed that Salmonella enterica RidA and Rid2, but not Rid7, can hydrolyze imines generated by amino acid oxidase. Genetic tests indicated that carbamoyl phosphate overproduction is toxic to S. enterica cells lacking RidA, and metabolomic profiling of Rid knockout strains showed ten-fold accumulation of the carbamoyl phosphate-related metabolite dihydroorotate.ConclusionsLike the archetypal RidA subfamily, the Rid2, and probably the Rid1 and Rid3 subfamilies, have imine-hydrolyzing activity and can pre-empt damage from imines formed by amine oxidases as well as by pyridoxal 5'-phosphate enzymes. The RidA subfamily has an additional damage pre-emption role in carbamoyl phosphate metabolism that has yet to be biochemically defined. Finally, the Rid4 to Rid7 subfamilies appear not to hydrolyze imines and thus remain mysterious

Imaging a Single-Electron Quantum Dot

Images of a single-electron quantum dot were obtained in the Coulomb blockade regime at liquid He temperatures using a cooled scanning probe microscope (SPM). The charged SPM tip shifts the lowest energy level in the dot and creates a ring in the image corresponding to a peak in the Coulomb-blockade conductance. Fits to the lineshape of the ring determine the tip-induced shift of the electron energy state in the dot. SPM manipulation of electrons in quantum dots promises to be useful in understanding, building and manipulating circuits for quantum information processing.Comment: 14 pages including 3 figure

Patient and researcher perspectives on facilitating patient and public involvement in rheumatology research

No abstract available

Impediments to Marketing African Natural products From Ghana: Preliminary Results

For most of the African countries agriculture still remains the mainstay of the economies supplying both food and incomes via marketable surpluses. However, many odds against agriculture such low productivity, poor prices, and drought among others make it unsustainable. Results thus far show that such dependence has contributed little to neither economic development nor growth. Still many of its people living on and from agriculture remain poor, and are susceptible to hunger and malnutrition. Additionally, their over reliance on a few traditional exports such coffee, tea, and cocoa etc., products whose world prices keep declining has not helped either. At most this is futile response to raising incomes of its people, let alone spur any meaningful development. Agricultural may still contribute to development, if the countries could diversify from traditional products to the untapped areas. The continent's rich botanical heritage offers an excellent opportunity to diversify away from traditional exports. The natural products have a greater appeal to consumers especially in the rich west. Thus, development of natural products as alternative or complimentary to the current mix of tradable products will positively impact the social and economic lives of many people, especially those in the rural areas. Additionally, diversification of the production systems to include natural plants provides a superior route to the creating viable agribusinesses in rural communities currently lacking. Natural products happen to have enormous advantages; First, indigenous African plants occur naturally and so are relatively easy to cultivate commercially. Second, natural plant production is labor intensive rather than capital intensive, and so minimizes capital investment while at the same time maximizing job-creation potential. Third, African communities have extensive knowledge of indigenous plants, creating a natural competitive advantage in this sector. ASNAPP (Agribusiness in Sustainable Natural African Plants Products) a non-profit organization formed in 1999 with funding from USAID (United States Agency for International Development) is helping create and develop successful African agribusinesses in the natural plant products sector. The organization focuses on the development of high-value natural plant products that enable African agribusinesses to compete in local, regional and international markets. These products include herbal teas, culinary herbs and spices, essential and press oils, as well as medicinal plants. Currently, ASNAPP operates in five countries, namely South Africa, Ghana, Rwanda, Senegal and Zambia, working with 25 agri-enterprises that represent more than 2000 small-scale natural plant suppliers. The prospects for natural products market is very bright, for example the global nutraceutical market alone is estimated to be worth $60 billion annually in sales of dietary and meal supplements, as well as specialty products. There is also increasing demand for organic and natural products such as herbal teas, essential oils, herbs and spices, phytomedicines and phytocosmetics. This growth has been supported by a global swing away from synthetic products to those that are natural, healthy, sustainably produced and fairly traded. In the context of world trade in natural products, African country's natural forests supply more herbs, medicinal plants and natural food ingredients. The Americans and Europeans are the major consumers of natural products in the global market. Products such as the herbal tea's, essential oils, cosmetic and spices have readily available markets. Natural product sales was estimated$34 billion in 2001, It is estimated that Global sales for organic and natural products will reach about $100 billion by 2008 at an annual growth rate of 20-30$316 million dollar business in 1996 to over $454 million in 2001(Alberta Essential Oils, 1996; Datamonitor, 2002). Indeed there is untapped potential ranging from raw products to processed ones, which could fetch even higher returns to the farmers. However, it is only a few large enterprises that are active in the sector, leaving rural communities who had in fact been the first to discover the health and nutritional properties of indigenous plants out in the cold. The ASNAPP Ghana program which commenced in 2000 is currently working on essential oils, lippia tea, grains of paradise, cryptolepis, kombo butter, shea butter and Artemisia, with the focus on the Eastern, Central, Ashanti, Volta, Greater Accra and Northern regions of Ghana. The natural products industry in Ghana is characterized by low input- low output; mostly operated by small-scale farmers (suppliers) with low levels of levels of formal education and agricultural production knowledge. In this respect the supply side problems may be summarized as regularity of the supplies, quality and timeliness. Organizationally, the scale of the operations may be a bottleneck one hand, on the other hand, information, capital; product quality and assurance mechanisms hinder successful commercialization. The domestic markets are largely at the low levels of commercialization; the operators have limited technical knowledge about natural products, and limited capital to expand their businesses and exploit the readily available foreign markets. Similarly, on the demand side, there may be lack of consumer information as to the range of products, where to find them and what remedies they offer. This paper has the objective of highlighting the marketing impediments facing the natural products market in the retail and wholesale portions of the chain in Ghana. Specifically, (i) profile the technical, financial, organizational, etc., constraints the traders face (domestically and externally), (ii) profile the natural product range and their functions (iii) suggest policy interventions. Preliminary results from the Ghana business survey show that seven out of ten of the businesses are retailer operated, whose two-thirds supply is dependent on the small-scale farmers. There results also show that virtually all the traders have not received any technical, financial or trade assistance from any organization. At most only 1 out of ten businesses have ventured into external trade. The preliminary results show tremendous potential, however a lot need to be done to tap on this potential. The analysis will be based on a survey that was carried out in Ghana to correct information on; product ranges; the supply chain (from production to the retail stores and potential for exports. The analysis will contribute toward inform policy of which marketing to be addressed and inform domestic and foreign consumers of the presence of such products. References: Alberta Agriculture, Food, and Rural Development, Herb/Spice Industry Fact Sheet. Compiled by Dennis Dey. AG-Ventures, Agdex 263/830-1, www.agric.gov.ab.ca, September 1996. Datamonitor, Nov 15, 2002. Marty T. S., and Patrick R., "Natural Product Sales Top$42 Billion" Natural Foods Merchandiser, 2004, volume XXV/number 6/ p. 1 Organic Natural health, 2001. http://www.health-report.co.uk/organic-cosmetics-usa- opportunity.htm#Organic/natural%20industry%20profileInternational Relations/Trade,

An Overview of Marketing of Ghana Natural Products

The study finds strong correlations between natural products business performance and the impeding factors. The impediments include access to finance and markets, lack of herbal market information especially relating to external markets. Additionally, there is lack of processing capacity, while at the same time most if not all the natural products business operators lack technical training relating to product handling. However, there is big potential for success, the top ten traded natural products, may be exploited initially, both domestically and for export market, given range of perceived use. The constraints identified require concerted efforts from all stakeholders to recognize the importance of this sub-sector in providing opportunities to successful development.Marketing,

A Comparison of Wholesaler/Retailer Business Characteristics of Natural Products between Ghana and Rwanda

The usage of natural products is becoming an increasingly common consumer phenomenon due to increasing health consciousness, and because of their naturalness, and medicinal qualities of the products. African countries are very rich with natural products resources and supplies. The continent’s rich botanical heritage offers an excellent opportunity to diversify away from other traditional exports. Europe and the USA are particularly promising markets for natural products. Thus, it is advantageous to examine development of natural products exporting as alternative or complimentary economic opportunities for many African people, especially those in the rural areas. This paper has explores both factors which promote and which act as obstacles to the natural products market, specifically in the retail and wholesale portions of the value chain in Ghana and Rwanda.Agribusiness,

Fast Sensing of Double-Dot Charge Arrangement and Spin State with a Radio-Frequency Sensor Quantum Dot

Single-shot measurement of the charge arrangement and spin state of a double quantum dot are reported with measurement times down to 100 ns. Sensing uses radio-frequency reflectometry of a proximal quantum dot in the Coulomb blockade regime. The sensor quantum dot is up to 30 times more sensitive than a comparable quantum point-contact sensor and yields three times greater signal to noise in rf single-shot measurements. Numerical modeling is qualitatively consistent with experiment and shows that the improved sensitivity of the sensor quantum dot results from reduced lifetime broadening and screening.PhysicsOther Research Uni