A transitory regime : water supply in Conakry, Guinea

Both consumers and the government benefited from reform of the water system in Conakry, Guinea, whose deterioration since independence had become critical by the mid-1980s. Less than 40 percent of Conakry's population had access to piped water - low even by regional standards - and service was intermittent, at best, for the few who had connections. The public agency in charge of the sector was inefficient, overstaffed, and virtually insolvent. In several ways, the reform introduced to the sector in 1989 under a World Bank-led project was remarkable. It showed that even in a weak institutional environment, where contracts are hard to enforce and political interference is common, private sector participation can improve sector performance. The authors discuss the mechanismsthat made progress possible and identify factors that inhibit the positive effects of reform. Water has become very expensive, the number of connections has increased very slowly, and conflicts have developed between SEEG (the private operator) and SONEG (the state agency). Among the underlying problems: a) The lack of strong, stable institutions. b) The lack of an independent agency capable of restraining arbitrary government action, regulating the private operator, and enforcing contractual arrangements. c) The lack of adequate conflict resolution mechanisms for contract disputes. d) Weak administrative capacity.Environmental Economics&Policies,Water and Industry,Water Conservation,Decentralization,Water Supply and Systems,Town Water Supply and Sanitation,Water and Industry,Water Supply and Sanitation Governance and Institutions,Environmental Economics&Policies,Water Conservation

The welfare effects of private sector participation in Guinea's urban water supply

In 1989 the government of Guinea enacted far-reaching reform of its water sector, which had been dominated by a poorly run public agency. The government signed a lease contract for operations and maintenance with a private operator, making a separate public enterprise responsible for ownershipof assets and investment. Although based on a successful model that had operated in Cote d'Ivoire for nearly 30 years, the reform had many highly innovative features. It is being transplanted to several other developing countries, so the authors evaluate its successes and failures in the early years of reform. They present standard performance measures and results from a cost-benefit analysis to assess reform's net effect on various stakeholders in the sector. They conclude that, compared with what might have been expected under continued public ownership, reform benefited consumers, the government, and, to a lesser extent, the foreign owners or the private operator. Most sector performance indicators improved, but some problems remain. The three most troublesome areas are water that is unaccounted for (there are many illegal connections and the quality of infrastructure is poor), poor collection rates, and high prices. The weak institutional environment makes it difficult to improve collection rates, but the government could take some steps to correct the problem. To begin with, it could pay its own bills on time. Also, the legislature could authorize the collection of unpaid bills from private individuals.Water Conservation,Environmental Economics&Policies,Water and Industry,Economic Theory&Research,Payment Systems&Infrastructure,Environmental Economics&Policies,Water and Industry,Water Supply and Sanitation Governance and Institutions,Water Conservation,Town Water Supply and Sanitation

Organizational Issues in the Agrifood Sector: Toward a Comparative Approach

Includes bibliographical references.This article outlines a research program comparing the economic organization of agriculture in the United States and European Union (EU). While both have highly developed agricultural sectors, there is substantial variation in organizational arrangements between and within the two. History and path dependence explain some of this variety, but other local conditions are important as well

Patchwork Gridshells::Using Modularity to Facilitate Prefabrication and Simplify Construction

Modern architectural design has seen a shift towards iconic doubly-curved envelopes enclosing large column-free spaces. Gridshells have long been considered an efficient solution to such designs, but their actual use in practice has not spread worldwide. For elastic gridshells, their advantages in terms of substantial material savings can often be overshadowed by the significant challenges associated with their construction. Similarly, for rigid gridshells, the manufacture of a large number of different members and nodal connections is often a barrier to their implementation. This paper proposes an effective way of designing, fabricating and erecting gridshells. The “Patchwork Gridshell” consists of a number of efficient elastic gridshell patches assembled using rigid gridshell frames. It can easily generate a number of different configurations, use a wide range of materials, and allows more architectural expression of practical long-span forms. The benefits of combining the ingenuously simple efficiency of elastic lattices and the power of digital fabrication are demonstrated by digitally rebuilding four alternative configurations of the Japan Pavilion of the Hanover Expo 2000 as a case study. The result is a flexible digital workflow which creates large column-free spaces that are capable of being constructed efficiently by nonspecialist contractors.</p

Patchwork Gridshells::Using Modularity to Facilitate Prefabrication and Simplify Construction

Modern architectural design has seen a shift towards iconic doubly-curved envelopes enclosing large column-free spaces. Gridshells have long been considered an efficient solution to such designs, but their actual use in practice has not spread worldwide. For elastic gridshells, their advantages in terms of substantial material savings can often be overshadowed by the significant challenges associated with their construction. Similarly, for rigid gridshells, the manufacture of a large number of different members and nodal connections is often a barrier to their implementation. This paper proposes an effective way of designing, fabricating and erecting gridshells. The “Patchwork Gridshell” consists of a number of efficient elastic gridshell patches assembled using rigid gridshell frames. It can easily generate a number of different configurations, use a wide range of materials, and allows more architectural expression of practical long-span forms. The benefits of combining the ingenuously simple efficiency of elastic lattices and the power of digital fabrication are demonstrated by digitally rebuilding four alternative configurations of the Japan Pavilion of the Hanover Expo 2000 as a case study. The result is a flexible digital workflow which creates large column-free spaces that are capable of being constructed efficiently by nonspecialist contractors.</p

Characterization of the Promoter, MxiE Box and 5′ UTR of Genes Controlled by the Activity of the Type III Secretion Apparatus in Shigella flexneri

Activation of the type III secretion apparatus (T3SA) of Shigella flexneri, upon contact of the bacteria with host cells, and its deregulation, as in ipaB mutants, specifically increases transcription of a set of effector-encoding genes controlled by MxiE, an activator of the AraC family, and IpgC, the chaperone of the IpaB and IpaC translocators. Thirteen genes carried by the virulence plasmid (ospB, ospC1, ospD2, ospD3, ospE1, ospE2, ospF, ospG, virA, ipaH1.4, ipaH4.5, ipaH7.8 and ipaH9.8) and five genes carried by the chromosome (ipaHa-e) are regulated by the T3SA activity. A conserved 17-bp MxiE box is present 5′ of most of these genes. To characterize the promoter activity of these MxiE box-containing regions, similar ∼67-bp DNA fragments encompassing the MxiE box of 14 MxiE-regulated genes were cloned 5′ of lacZ in a promoter probe plasmid; β-galactosidase activity detected in wild-type and ipaB strains harboring these plasmids indicated that most MxiE box-carrying regions contain a promoter regulated by the T3SA activity and that the relative strengths of these promoters cover an eight-fold range. The various MxiE boxes exhibiting up to three differences as compared to the MxiE box consensus sequence were introduced into the ipaH9.8 promoter without affecting its activity, suggesting that they are equally efficient in promoter activation. In contrast, all nucleotides conserved among MxiE boxes were found to be involved in MxiE-dependent promoter activity. In addition, we present evidence that the 5′ UTRs of four MxiE-regulated genes enhance expression of the downstream gene, presumably by preventing degradation of the mRNA, and the 5′ UTRs of two other genes carry an ancillary promoter

Campylobacter Antimicrobial Drug Resistance among Humans, Broiler Chickens, and Pigs, France

We describe isolates from human Campylobacter infection in the French population and the isolates' antimicrobial drug resistance patterns since 1986 and compare the trends with those of isolates from broiler chickens and pigs from 1999 to 2004. Among 5,685 human Campylobacter isolates, 76.2% were C. jejuni, 17.2% C. coli, and 5.0% C. fetus. Resistance to nalidixic acid increased from 8.2% in 1990 to 26.3% in 2004 (p<10-3), and resistance to ampicillin was high over time. Nalidixic acid resistance was greater for C. coli (21.3%) than for C. jejuni (14.9%, p<10-3). C. jejuni resistance to ciprofloxacin in broilers decreased from 31.7% in 2002 to 9.0% in 2004 (p = 0.02). The patterns of resistance to quinolones and fluoroquinolones were similar between 1999 and 2004 in human and broiler isolates for C. jejuni. These results suggest a potential benefit of a regulation policy limiting use of antimicrobial drugs in food animals

The Entomopathogenic Bacterial Endosymbionts Xenorhabdus and Photorhabdus: Convergent Lifestyles from Divergent Genomes

Members of the genus Xenorhabdus are entomopathogenic bacteria that associate with nematodes. The nematode-bacteria pair infects and kills insects, with both partners contributing to insect pathogenesis and the bacteria providing nutrition to the nematode from available insect-derived nutrients. The nematode provides the bacteria with protection from predators, access to nutrients, and a mechanism of dispersal. Members of the bacterial genus Photorhabdus also associate with nematodes to kill insects, and both genera of bacteria provide similar services to their different nematode hosts through unique physiological and metabolic mechanisms. We posited that these differences would be reflected in their respective genomes. To test this, we sequenced to completion the genomes of Xenorhabdus nematophila ATCC 19061 and Xenorhabdus bovienii SS-2004. As expected, both Xenorhabdus genomes encode many anti-insecticidal compounds, commensurate with their entomopathogenic lifestyle. Despite the similarities in lifestyle between Xenorhabdus and Photorhabdus bacteria, a comparative analysis of the Xenorhabdus, Photorhabdus luminescens, and P. asymbiotica genomes suggests genomic divergence. These findings indicate that evolutionary changes shaped by symbiotic interactions can follow different routes to achieve similar end points

La diversité des modes d’organisation dans l’agroalimentaire : quelle logique ? Quelles conséquences ?

International audienceRecent developments in organization theory help us think about a reality that economists and decision-makers have much underestimated, namely: the variety of the forms of organization of business activities and their underlying motivations. After focusing on the endogenous determinants that enable us to set in order the apparently prolific list of organizational forms, the technological and institutional components are discussed that have shaped this complex landscape and account for its evolution. Discussion then turns to the consequences of this variety of organization forms on public policymaking. The underlying message is that the variety of forms of organization in agribusiness is subject to deep, resilient forces that force us to redesign public policies.Les développements récents de la théorie des organisations fournissent des outils pour penser une réalité largement sous-estimée par les économistes et les décideurs : la diversité des modalités d’organisation de l’activité économique et les motivations derrière les choix effectués. Dans cet article, nous portons d’abord notre attention sur les déterminants endogènes permettant d’ordonner le tableau en apparence touffu du monde des organisations. Nous faisons ensuite état des composantes technologiques et institutionnelles contribuant à façonner ce paysage complexe et à en expliquer l’évolution. Nous terminons notre propos par une série d’observations sur les conséquences de cette diversité pour les politiques publiques. Le message central sous-jacent à cet article est que la variété des modes d’organisation, dans l’agroalimentaire comme ailleurs, obéit à des forces profondes et résilientes qui obligent à repenser les politiques publiques