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Practical Means (practical + mean)
Selected AbstractsA Dual-track Strategy for Managing Mauritania's Projected Oil RentDEVELOPMENT POLICY REVIEW, Issue 1 2008Richard Auty High rent creates contests for its capture that, unless skilfully managed, degrade political institutions and distort the economy, leading to a collapse of growth if unreformed. Mauritania's projected oil stream risks such an outcome because past rent-driven growth has left a legacy of Dutch disease effects, rent-seeking and dependent social capital. This article proposes a dual-track strategy for deploying the oil rent as a politically practical means of managing social tensions and improving the economic outcome. Track one promotes a dynamic market economy in the hitherto neglected rural areas, while track two gradually reforms the rent-driven urban sector, thus postponing confrontation with established rent-seekers while the dynamic sector drives competitive diversification of the economy and builds a pro-reform political constituency. [source] History of hemodialyzers' designsHEMODIALYSIS INTERNATIONAL, Issue 2 2008Zbylut J. TWARDOWSKI Abstract Accumulation of knowledge requisite for development of hemodialysis started in antiquity and continued through Middle Ages until the 20th century. Firstly, it was determined that the kidneys produce urine containing toxic substances that accumulate in the body if the kidneys fail to function properly; secondly, it was necessary to discover the process of diffusion and dialysis; thirdly, it was necessary to develop a safe method to prevent clotting in the extracorporeal circulation; and fourthly, it was necessary to develop biocompatible dialyzing membranes. Most of the essential knowledge was acquired by the end of the 19th century. Hemodialysis as a practical means of replacing kidney function started and developed in the 20th century. The original hemodialyzers, using celloidin as a dialyzing membrane and hirudin as an anticoagulant, were used in animal experiments at the beginning of the 20th century, and then there were a few attempts in humans in the 1920s. Rapid progress started with the application of cellophane membranes and heparin as an anticoagulant in the late 1930s and 1940s. The explosion of new dialyzer designs continued in the 1950s and 1960s and ended with the development of capillary dialyzers. Cellophane was replaced by other dialyzing membranes in the 1960s, 1970s, and 1980s. Dialysis solution was originally prepared in the tank from water, electrolytes, and glucose. This solution was recirculated through the dialyzer and back to the tank. In the 1960s, a method of single-pass dialysis solution preparation and delivery system was designed. A large quantity of dialysis solution was used for a single dialysis. Sorbent systems, using a small volume of regenerated dialysis solution, were developed in the mid 1960s, and continue to be used for home hemodialysis and acute renal failure. At the end of the 20th century, a new closed system, which prepared and delivered ultrapure dialysis solution preparation, was developed. This system also had automatic reuse of lines and dialyzers and prepared the machine for the next dialysis. This was specifically designed for quotidian home hemodialysis. Another system for frequent home hemodialysis or acute renal failure was developed at the turn of the 21st century. This system used premanufactured dialysis solution, delivered to the home or dialysis unit, as is done for peritoneal dialysis. [source] A potent adjuvant effect of CD40 antibody attached to antigenIMMUNOLOGY, Issue 1 2003Tom A. Barr Summary There is great potential for novel vaccines based on recombinant proteins and synthetic peptides. Unfortunately these antigens often lack the immunogenicity of whole, killed pathogens used in traditional vaccines. Thus there is strong interest in the identification of immunological adjuvants with low reactogenicity, but high potency, to enhance immune responses and realize the potential of these new vaccine strategies. CD40 antibodies have been shown to have adjuvant effects when administered at very high doses. These large doses are impractical and induce a cascade of cytokine release giving rise to septic shock-like symptoms, as well as splenomegaly and polyclonal antibody production. We show here that a very small amount of CD40 antibody can exhibit potent adjuvant effects when attached to soluble antigen. The lack of detectable systemic effects indicates that this method may be a powerful and practical means of enhancing the efficacy of recombinant vaccines. [source] Sources and migration of volatile organic compounds in mixed-use buildingsINDOOR AIR, Issue 5 2010C. Jia Abstract, We examined concentrations and migration of volatile organic compounds (VOCs) in ten mixed-use buildings in southeast Michigan, USA. In an office and work zone in each building, air exchange rates (AERs) were measured using perfluorocarbon tracers, and over 96 VOC species were measured by GC/MS over a 7-day period. VOCs were then apportioned to sources in offices, work zones, and outdoors using a two-zone mass balance model. AERs averaged 3.9 h (0.2,14.2 h) in offices and 1.9 h (0.4,3.5 h) in work zones. The dominant VOCs included aromatics, terpenes and alkanes. VOC concentrations were uniform in the smaller spaces, and more variable in some of the very large spaces. Apportionments depended on the VOC and building, but emissions in industrial zones of buildings often migrated to office areas where they frequently accounted for the bulk of VOC concentrations. Outdoor sources accounted for most benzene and carbon tetrachloride, and a small fraction of aromatic and aliphatic compounds. This study shows that pollutant migration can be a significant and not uncommon problem in mixed-use buildings, and it demonstrates the need for better control of emissions and pollutant migration. Practical Implications Pollutant exposures in industrial, commercial, and institutional buildings arise from indoor and outdoor sources that can be identified, apportioned, and controlled with knowledge of emission sources and building airflows. We show that multi-tracer techniques are an effective and practical means of determining airflows and exchange rates in large buildings. In examining a set of mixed-use buildings, a substantial fraction of VOC exposures in otherwise relatively ,clean' offices is due to pollutant migration from ,dirty' zones of the building. This indicates the need for corrective actions to minimize exposures of office workers that are unwanted and probably unknown to building managers. These actions should include better control of emissions, isolation or control of air and pollutant flows between building zones, and documentation of the effectiveness of such measures when strong emission sources are present. [source] The effect of introducing pipelines into irrigation water distribution systems on the farm economy: a case study in the Southern Governorates Rural Development Project, Republic of Yemen,IRRIGATION AND DRAINAGE, Issue 1 2001Rozgar Baban le Yémen; eau souterraine; irrigation; tuyaux Abstract The Southern Governorates Rural Development Project (SGRDP) is a comprehensive participatory rural development project covering three of the five southern Governorates of the Republic of Yemen, namely Hadramaut, Abyan and Lahij. Its objective is to alleviate poverty in rural areas of these three Governorates. A major component of the project is to develop virgin lands for agriculture and allocate each 5 feddan (FD) plot to those farmers who do not own land (1 FD=4200 m2). As the annual rainfall in the project area is less than 100 mm and since landlords and other farmers already own lands suitable for agriculture in the major wadis, the only source of irrigation water in the newly developed land is the groundwater (GW). The SGRDP is aware of the scarcity of water resources in the country, particularly in the project area; it therefore makes every possible effort to optimize the use of GW for irrigation by practical means. One way of reducing GW used for irrigation is by replacing major canals in the farms by buried pipelines. This method has been tried in small-scale individual farms outside the project area and it proved that farmers could adapt to the system without difficulty. Sprinkler and drip irrigation systems have been tried in many previous agricultural development projects in the country but with no apparent success, as far as the farmers' adoption of the method is concerned. Thus, the project, as the first stage to reduce the use of GW for irrigation in the newly developed areas, planned to eliminate, initially, the conveyance losses by replacing the open canals by buried PVC pipes. In this paper, it is attempted to show that the use of buried pipes in small scale irrigation schemes is financially feasible, even if the indirect and non-tangible environmental benefits are not considered. This paper deals only with special GW schemes recommended for the project area; however, the outcome could be generalized and applied elsewhere in the country. Copyright © 2001 John Wiley & Sons Ltd. Le Projet de Développement Rural des Gouvernorats du Sud (SGRDP) est un ensemble de projet de développement rural participatif de trois des cinq Gouvernorats de la République de Yémen à savoir Hadramaut, Abyan et Lahij. Son objectif est d'atténuer la pauvreté dans les régions rurales de ces Gouvernorats. L'une des principales activités de ce projet concerne le développement des terres incultes pour l'agriculture. Ce développement passe par l'allocation de parcelles de 5 FD à chaque agriculteur sans terre. Comme la pluviosité annuelle dans cette région est inférieure à 100 mm et que les propriétaires et les autres fermiers disposent déjà des terres aptes à l'agriculture dans les WADIS importants, l'eau souterraine est la seule source d'eau pour l'irrigation des terres nouvellement développées. Compte tenu de la rareté des ressources en eau, particulièrement dans la région du projet, le SGRDP s'efforce d'optimiser l'utilisation de l'eau souterraine (ES) pour l'irrigation en adoptant des moyens pratiques. L'un des moyens de réduire l'ES utilisée en irrigation consiste à remplacer les principaux canaux des fleuves par des tuyaux enterrés. Cette méthode a été utilisée à titre d'essai dans des exploitations individuelles de petite taille en dehors de la région du projet, et il s'est avéré que les agriculteurs peuvent s'adapter à ce système sans difficultés. Les systèmes d'irrigation par aspersion et goutte à goutte ont été essayés dans de nombreux anciens projets de développement agricoles du pays, mais sans succès apparent quant à l'adoption de cette méthode par les fermiers. Ainsi, le projet, en tant que première stade de réduction de l'ES pour l'irrigation dans les régions nouvellement développées, a proposé d'éliminer au début les pertes par transport en remplaçant les canaux ouverts par des tuyaux PVC enterrés. Ce rapport essaie de montrer que l'utilisation des tuyaux enterrés dans les projets d'irrigation de petite taille, est faisable du point de vue économique même en faisant abstraction des avantages indirects et non tangibles provenant de l'environnement. Le rapport traite seulement des projets spéciaux de l'ES recommandés pour la région du projet. Cependant, les résultats peuvent être généralisés et appliqués aux autres régions du pays. Copyright © 2001 John Wiley & Sons Ltd. [source] Hepatitis B vaccine: Risks and benefits of universal neonatal vaccinationJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 3 2001CR Macintyre Abstract: Global eradication of hepatitis B, which has infected over 2000 million people worldwide, is an achievable goal. Hepatitis B vaccine is effective and safe, and is recommended in Australia as a four-dose childhood schedule commencing with a neonatal dose. A neonatal dose has a greater impact on carriage, the main reservoir of transmission, due to the inverse relationship of age and risk of chronic carriage. Universal vaccination is clearly cost-effective in countries of high hepatitis B endemicity but less so in countries of low endemicity. Other factors affecting the perceived benefits of universal vaccination in low-risk countries include the use of the preservative thiomersal in hepatitis B vaccines, and case reports of multiple sclerosis (MS) and unexplained fever in recipients. Careful epidemiological studies have failed to confirm any risk of MS or fever with the hepatitis B vaccine, which is now thiomersal-free. Other arguments against universal vaccination include ,unnecessary' vaccination of low-risk neonates. However, selective vaccination programmes targeting at-risk neonates are often poorly implemented and do not protect against horizontal transmission in early childhood. Universal vaccination, which is safe and effective, is the only practical means of achieving global eradication of hepatitis B. [source] Human mesenchymal stem cells as a stable source of VEGF-producing cellsJOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 4 2008Harumi Kagiwada Abstract Vascular endothelial growth factor (VEGF) is a positive regulator and plays a crucial role in angiogenesis. We demonstrate that VEGF was highly expressed in cultures of human bone marrow-derived mesenchymal stem cells (hMSCs) and the high expression level was maintained during prolonged culture periods (checked up to passage 10). We also confirmed that in vivo hMSCs engrafted into immunodeficient mice could survive and secreted human VEGF. These findings suggest that implantation of hMSCs is a practical means as a source of VEGF production and might be effective in neoangiogenesis. Copyright © 2008 John Wiley & Sons, Ltd. [source] Semiarid land rehabilitation by direct drilling in the South Island, New Zealand,plant species and establishment technologyLAND DEGRADATION AND DEVELOPMENT, Issue 5 2004B. J. Wills Abstract Large areas of the east coast and inland basins of the South Island, New Zealand, are affected by periodic drought and/or semiarid climatic conditions, particularly during cyclic El Niño climatic events. The severity of these environmental conditions places great stress on introduced and native pasture species and frequently results in poor establishment of new pastures using standard drilling techniques. The objective of this study was to determine effective, practical means of rehabilitating semiarid land (about 470,mm annual rainfall) on a site in Central Otago. A comparison of two direct drilling methods, a novel strip-seeder drill and a standard hoe-coulter drill, was conducted in a trial initiated during spring 1998. Five drought-tolerant forage species were established: wheatgrass (Thinopyron intermedium), tall oat grass (Arrhenatherum elatius), birdsfoot trefoil (Lotus corniculatus), hairy dorycnium (Dorycnium hirsutum) and bluebush (Kochia prostrata). For the 2000/2001 growing season, species established with the strip-seeder drill had an overall mean herbage biomass of 235,g,m,,2,, three-times that for the hoe-coulter drill (77,g,m,,2,, P,<,0·001). Differences in herbage biomass between species were observed, with hairy dorycnium (mean 328,g,m,,2,) producing significantly (P,<,0·001) more herbage biomass than the other species. After the third spring, the percentage ground cover recorded from transects across the strip-seeder drill plots (cf. the hoe-coulter drill) was: wheatgrass,41,per,cent (10,per,cent); tall oat grass,44,per,cent (25,per,cent); birdsfoot trefoil,25,per,cent (5,per,cent); hairy dorycnium,50,per,cent (19,per,cent); and bluebush,4,per,cent (0,per,cent). The native plant content of the resident vegetation was reduced as a result of the drilling treatments and also when fertilizer was added to undistrubed pasture. The strip-seeder drill is capable of providing superior plant growth on dryland sites even during adverse drought conditions. It produces a furrow approximately 16,cm wider than the hoe-coulter drill, exerts a greater shattering effect on the soil structure and places fertilizer at depth. It is suggested that this assists plant establishment by providing good seedling protection from wind and sun, and subsequent plant growth by allowing easier root penetration to the subsoil where nutrients and moisture are available. Copyright © 2004 John Wiley & Sons, Ltd. [source] Spaces of silence: single parenthood and the ,normal family' in SingaporePOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 1 2004Theresa Wong Abstract Alternative family forms have begun to emerge in the Confucian societies of East and Southeast Asia, concomitant with widespread demographic changes and new socioeconomic conditions. In Singapore, the state tends to configure ,single parents' , including divorcees, unmarried parents and widowed parents , as ,unfortunate' and constituting an unhealthy trend, in opposition to the normal, dual-parent household. This paper examines how single parents in Singapore reconfigure their definitions of the family both discursively and through practical means, in response to the ,traditional', Confucian concept of the complete family propounded by the government. Through in-depth interviews with middle-class Chinese Singaporean single mothers and fathers, this paper also explores how single parents employ strategies at two levels: in practical decisions relating to childcare; and discursively, through the articulation of remarriage and fertility desires, in which patriarchal notions of the roles of husband/wife and mother/father are embedded. Copyright © 2004 John Wiley & Sons, Ltd. [source] Operation of a municipal solid waste co-combustion pilot plantASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2007V. K. C. Lee Abstract The co-combustion of municipal solid waste (MSW) is a novel and highly integrated design combining cement manufacturing, thermal processing of MSW and energy/electricity production (termed the Co-Co process). This novel design of the Co-Co process was developed in 2003,2004 and a pilot plant with a capacity of 40 tonnes per day was constructed and commissioned in 2005. The pilot plant was operated for a period of 10 weeks during 2005. Various feed protocols, namely, MSW as received and after removal of recyclables, were tested. Stack emissions were monitored either continuously (gas emission) or periodically (dioxins and heavy metal emissions). Solid residues including bottom ash and fly ash were also sampled and analysed for heavy metals and dioxins periodically. It was found that the levels of dioxins in the stack emissions and fly ash were below normal MSW thermal treatment processes, and government environmental and international limits (more than 1000 times less). Other gases, such CO, NOx, SOx and HCl, were also well below government environmental licence limits as defined by a best practical means (BPM). In addition, the materials recovery and recycling facility (MRRF) was tested. It demonstrated that different fractions, including metals, plastics and glass, of the MSW could be separated and recovered. The Co-Co process was successfully demonstrated and its emission levels were well below normal MSW thermal treatment processes. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Gas-Liquid Mass Transfer in a Slurry Bubble Column at High Slurry Concentrations and High Gas VelocitiesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 9 2005C. O. Vandu Abstract The volumetric mass transfer coefficient kLa in a 0.1,m-diameter bubble column was studied for an air-slurry system. A C9 -C11n -paraffin oil was employed as the liquid phase with fine alumina catalyst carrier particles used as the solid phase. The n -paraffin oil had properties similar to those of the liquid phase in a commercial Fischer-Tropsch reactor under reaction conditions. The superficial gas velocity UG was varied in the range of 0.01 to 0.8,m/s, spanning both the homogeneous and heterogeneous flow regimes. The slurry concentration ,S ranged from 0 to 0.5. The experimental results obtained show that the gas hold-up ,G decreases with an increase in slurry concentration, with this decrease being most significant when ,S < 0.2. kLa/,G was found to be practically independent of the superficial gas velocity when UG > 0.1,m/s is taking on values predominantly between 0.4 and 0.6,s,1 when ,S = 0.1 to 0.4, and 0.29,s,1, when ,S = 0.5. This study provides a practical means for estimating the volumetric mass transfer coefficient kLa in an industrial-size bubble column slurry reactor, with a particular focus on the Fischer-Tropsch process as well as high gas velocities and high slurry concentrations. 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