169 research outputs found

    A Political Economy of Privatization Contracts : The Case of Water and Sanitation in Ghana and Argentina

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    This document is the Accepted Manuscript version of the following article: Hulya Dagdeviren, Simon A. Robertson, 'A Political Economy of Privatization Contracts: The Case of Water and Sanitation in Ghana and Argentina', Competition & Change, Vol. 18 (2): 150-163, April 2014. The final, published version is available online at DOI: https://doi.org/10.1179/1024529414Z.00000000053. Published by SAGE.In general, the process and outcomes of privatization have been studied from the point of view of efficiency. In this article, we consider issues in the course of contract design, implementation, management and enforcement in privatized public services and utilities. The study is based on two case studies, involving several water concessions in Argentina and a management contract in the urban water sector in Ghana. Three key arguments are presented on the basis of these case studies. The first is that an individualistic analytical framework is often utilized by the mainstream economic perspectives, but these are inadequate for a comparative assessment of private versus public provision in public services where there are distinct collective or group interests and hence a wider socio-economic context and representation of different interests becomes highly important. Instead, the article proposes a political economy perspective, which pays due attention to distributional issues, group interests, ideology of states and power relations for the assessment of privatization contracts. Second, the administrative capacity of states and their resources play a key role for the outcomes of privatization. Finally, while some contractual issues could be resolved through resourcing and experience over time, others are inherent to the contractual relations with little prospect of remedy.Peer reviewe

    Retrieving and Recommending for the Classroom: Stakeholders, Objectives, Resources, and Users

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    In this paper, we consider the promise and challenges of deploying recommendation and information retrieval technology to help teachers locate resources for use in classroom instruction. The classroom setting is a complex environment presenting a number of challenges for recommendation, due to its inherent multi-stakeholder nature, the multiple objectives that quality educational resources and experiences must simultaneously satisfy, and potential disconnect between the direct user of the system and the end users of the resources it provides. In this paper, we outline these challenges, highlight opportunities for new research, and describe our work in progress in this area including insights from interviews with working teachers

    Nerve growth factor induces neurite outgrowth of PC12 cells by promoting Gβγ-microtubule interaction

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    Background: Assembly and disassembly of microtubules (MTs) is critical for neurite outgrowth and differentiation. Evidence suggests that nerve growth factor (NGF) induces neurite outgrowth from PC12 cells by activating the receptor tyrosine kinase, TrkA. G protein-coupled receptors (GPCRs) as well as heterotrimeric G proteins are also involved in regulating neurite outgrowth. However, the possible connection between these pathways and how they might ultimately converge to regulate the assembly and organization of MTs during neurite outgrowth is not well understood. Results: Here, we report that Gβγ, an important component of the GPCR pathway, is critical for NGF-induced neuronal differentiation of PC12 cells. We have found that NGF promoted the interaction of Gβγ with MTs and stimulated MT assembly. While Gβγ-sequestering peptide GRK2i inhibited neurite formation, disrupted MTs, and induced neurite damage, the Gβγ activator mSIRK stimulated neurite outgrowth, which indicates the involvement of Gβγ in this process. Because we have shown earlier that prenylation and subsequent methylation/demethylation of γ subunits are required for the Gβγ-MTs interaction in vitro, small-molecule inhibitors (L-28 and L-23) targeting prenylated methylated protein methyl esterase (PMPMEase) were tested in the current study. We found that these inhibitors disrupted Gβγ and ΜΤ organization and affected cellular morphology and neurite outgrowth. In further support of a role of Gβγ-MT interaction in neuronal differentiation, it was observed that overexpression of Gβγ in PC12 cells induced neurite outgrowth in the absence of added NGF. Moreover, overexpressed Gβγ exhibited a pattern of association with MTs similar to that observed in NGF-differentiated cells. Conclusions: Altogether, our results demonstrate that βγ subunit of heterotrimeric G proteins play a critical role in neurite outgrowth and differentiation by interacting with MTs and modulating MT rearrangement. Electronic supplementary material The online version of this article (doi:10.1186/s12868-014-0132-4) contains supplementary material, which is available to authorized users

    Contribution of Distinct Homeodomain DNA Binding Specificities to Drosophila Embryonic Mesodermal Cell-Specific Gene Expression Programs

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    Homeodomain (HD) proteins are a large family of evolutionarily conserved transcription factors (TFs) having diverse developmental functions, often acting within the same cell types, yet many members of this family paradoxically recognize similar DNA sequences. Thus, with multiple family members having the potential to recognize the same DNA sequences in cis-regulatory elements, it is difficult to ascertain the role of an individual HD or a subclass of HDs in mediating a particular developmental function. To investigate this problem, we focused our studies on the Drosophila embryonic mesoderm where HD TFs are required to establish not only segmental identities (such as the Hox TFs), but also tissue and cell fate specification and differentiation (such as the NK-2 HDs, Six HDs and identity HDs (I-HDs)). Here we utilized the complete spectrum of DNA binding specificities determined by protein binding microarrays (PBMs) for a diverse collection of HDs to modify the nucleotide sequences of numerous mesodermal enhancers to be recognized by either no or a single subclass of HDs, and subsequently assayed the consequences of these changes on enhancer function in transgenic reporter assays. These studies show that individual mesodermal enhancers receive separate transcriptional input from both I–HD and Hox subclasses of HDs. In addition, we demonstrate that enhancers regulating upstream components of the mesodermal regulatory network are targeted by the Six class of HDs. Finally, we establish the necessity of NK-2 HD binding sequences to activate gene expression in multiple mesodermal tissues, supporting a potential role for the NK-2 HD TF Tinman (Tin) as a pioneer factor that cooperates with other factors to regulate cell-specific gene expression programs. Collectively, these results underscore the critical role played by HDs of multiple subclasses in inducing the unique genetic programs of individual mesodermal cells, and in coordinating the gene regulatory networks directing mesoderm development.National Institutes of Health (U.S.) (Grant R01 HG005287

    Sharp boundaries of Dpp signalling trigger local cell death required for Drosophila leg morphogenesis

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    Article available at http://dx.doi.org/10.1038/ncb1518Morphogens are secreted signalling molecules that govern many developmental processes1. In the Drosophila wing disc, the transforming growth factor (TGF) homologue Decapentaplegic (Dpp) forms a smooth gradient and specifies cell fate by conferring a defined value of morphogen activity. Thus, neighbouring cells have similar amounts of Dpp protein, and if a sharp discontinuity in Dpp activity is generated between these cells, Jun kinase (JNK)-dependent apoptosis is triggered to restore graded positional information2, 3. To date, it has been assumed that this apoptotic process is only activated when normal signalling is distorted. However, we now show that a similar process occurs during normal development: rupture in Dpp activity occurs during normal segmentation of the distal legs of Drosophila. This sharp boundary of Dpp signalling, independently of the absolute level of Dpp activity, induces a JNK—reaper-dependent apoptosis required for the morphogenesis of a particular structure of the leg, the joint. Our results show that Dpp could induce a developmental programme not only in a concentration dependent manner, but also by the creation of a sharp boundary of Dpp activity. Furthermore, the same process could be used either to restore a normal pattern in response to artificial disturbance or to direct a morphogenetic process.This work has been supported by grants from the Dirección General de Investigación Científica y Técnica (BMC 2002-00300), the Comunidad Autónoma de Madrid (08.1/0031/2001.1 and GR/SAL/0147/2004) and an Institutional Grant from the Fundación Ramón Areces. C.M. is a recipient of a Formación del Personal Universitario (F.P.U.) fellowship from the Ministerio de Educación y Ciencia.Peer reviewe

    Different sensitivity of flower-visiting diptera to a neonicotinoid insecticide: expanding the base for a multiple-species risk assessment approach

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    Simple Summary Insect pollinators play an essential service in agricultural systems, but are commonly exposed to pesticides. Although pollinators are present in several insect orders, above all dipterans, information on pesticide sensitivity is mostly restricted to bees. We assessed the sensitivity of two hoverflies (Sphaerophoria rueppellii, Eristalinus aeneus) and one tachinid fly (Exorista larvarum) to a neonicotinoid insecticide (Confidor (R), imidacloprid). We adapted the standardized methodology of acute contact exposure in honey bees to build dose-response curves and calculate median lethal doses (LD50) for the three species. S. rueppelli was the most sensitive, E. aeneus the least. Results were compared with those available in the literature for other pollinator species using a species sensitivity distribution (SSD) approach: as a result, the 95th percentile of pollinator species would be protected by a safety factor of 100 times the Apis mellifera endpoint. Dipterans were less sensitive to imidacloprid than most bee species. We measured the number of eggs laid following exposure to different insecticide doses and assessed the potential trade-off between oviposition and survival through the sublethal sensitivity index (SSI). Pesticide exposure had a significant effect on fecundity, and SSI values indicated that oviposition is a sensitive endpoint for the three dipteran species tested.Abstract Insects play an essential role as pollinators of wild flowers and crops. At the same time, pollinators in agricultural environments are commonly exposed to pesticides, compromising their survival and the provision of pollination services. Although pollinators include a wide range of species from several insect orders, information on pesticide sensitivity is mostly restricted to bees. In addition, the disparity of methodological procedures used for different insect groups hinders the comparison of toxicity data between bees and other pollinators. Dipterans are a highly diverse insect order that includes some important pollinators. Therefore, in this study, we assessed the sensitivity of two hoverflies (Sphaerophoria rueppellii, Eristalinus aeneus) and one tachinid fly (Exorista larvarum) to a neonicotinoid insecticide (Confidor (R), imidacloprid) following a comparative approach. We adapted the standardized methodology of acute contact exposure in honey bees to build dose-response curves and calculate median lethal doses (LD50) for the three species. The methodology consisted in applying 1 mu L of the test solution on the thorax of each insect. Sphaerophoria rueppelli was the most sensitive species (LD50 = 10.23 ng/insect), and E. aeneus (LD50 = 18,176 ng/insect) the least. We then compared our results with those available in the literature for other pollinator species using species sensitivity distribution (SSD). Based on the SSD curve, the 95th percentile of pollinator species would be protected by a safety factor of 100 times the Apis mellifera endpoint. Overall, dipterans were less sensitive to imidacloprid than most bee species. As opposed to most bee species, oviposition and fecundity of many dipteran species can be reliably assessed in the laboratory. We measured the number of eggs laid following exposure to different insecticide doses and assessed the potential trade-off between oviposition and survival through the sublethal sensitivity index (SSI). Exposure to imidacloprid had a significant effect on fecundity, and SSI values indicated that oviposition is a sensitive endpoint for the three dipteran species tested.Future studies should integrate this information related to population dynamics in simulation models for environmental risk assessment

    Chronic oral toxicity protocol for adult solitary bees (Osmia bicornis L.): Reduced survival under long-term exposure to a “bee-safe” insecticide

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    Pollinators are essential for crop productivity. Yet, in agricultural areas, they may be threatened by pesticide exposure. Current pesticide risk assessments predominantly focus on honey bees, with a lack of standardized protocols for solitary bees. This study addresses this gap by developing a long-term oral exposure protocol tailored for O. bicornis. We conducted initial trials to determine optimal container sizes and feeding methods, ensuring high survival rates and accurate syrup consumption measurements. A validation test involving five laboratories was then conducted with the insecticide Flupyradifurone (FPF). Control mortality thresholds were set at ≤ 15% at 10 days. Three laboratories achieved ≤10%, demonstrating the protocol's effectiveness in maintaining healthy test populations. The seasonal timing of experiments influenced control mortality, underscoring the importance of aligning tests with the natural flight period of the population used. Our findings revealed dose-dependent effects of FPF on syrup consumption, showing stimulatory effects at lower concentrations and inhibitory effects at higher ones. The 10-day median lethal daily dose (LDD50) of FPF for O. bicornis (531.92 ng/bee/day) was 3.4-fold lower than that reported for Apis mellifera (1830 ng/bee/day), indicating Osmia's higher susceptibility. Unlike other insecticides, FPF did not exhibit time-reinforced toxicity. This study introduces a robust protocol for chronic pesticide exposure in solitary bees, addressing a critical gap in current risk assessment. Based on its low risk to honey bees and bumblebees, FPF is approved for application during flowering. However, our results suggest that it may threaten Osmia populations under realistic field conditions. Our findings underscore the need for comparative toxicity studies to ensure comprehensive protection of all pollinators and the importance of accounting for long term exposure scenarios in risk assessment. By enhancing our understanding of chronic pesticide effects in solitary bees, our study should contribute to the development of more effective conservation strategies and sustainable agricultural practices

    Pharmaceutical cost control in primary care: opinion and contributions by healthcare professionals

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    <p>Abstract</p> <p>Background</p> <p>Strategies adopted by health administrations and directed towards drug cost control in primary care (PC) can, according to earlier studies, generate tension between health administrators and healthcare professionals. This study collects and analyzes the opinions of general practitioners (GPs) regarding current cost control measures as well as their proposals for improving the effectiveness of these measures.</p> <p>Methods</p> <p>A qualitative exploratory study was carried out using 11 focus groups composed of GPs from the Spanish regions of Aragon, Catalonia and the Balearic Islands. A semi-structured guide was applied in obtaining the GPs' opinions. The transcripts of the dialogues were analyzed by two investigators who independently considered categorical and thematic content. The results were supervised by other members of the team, with overall responsibility assigned to the team leader.</p> <p>Results</p> <p>GPs are conscious of their public responsibility with respect to pharmaceutical cost, but highlight the need to spread responsibility for cost control among the different actors of the health system. They insist on implementing measures to improve the quality of prescriptions, avoiding mere quantitative evaluations of prescription costs. They also suggest moving towards the self-management of the pharmaceutical budget by each health centre itself, as a means to design personalized incentives to improve their outcomes. These proposals need to be considered by the health administration in order to pre-empt the feelings of injustice, impotence, frustration and lack of motivation that currently exist among GPs as a result of the implemented measures.</p> <p>Conclusion</p> <p>Future investigations should be oriented toward strategies that involve GPs in the planning and management of drug cost control mechanisms. The proposals in this study may be considered by the health administration as a means to move toward the rational use of drugs while avoiding concerns about injustice and feelings of impotence on the part of the GPs, which can lead to lack of interest in and disaffection with the current measures.</p

    Challenges of Exporting Differentiated Products to Developed Countries: The Case of SME-Dominated Sectors in a Semi-Industrialized Country

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    This paper surveys four Argentinean industrieslight ships, television programs, wines, and wooden furniturethat have experienced substantial export growth in recent years, particularly to developed countries. The case studies first describe the structure of the industries, then characterize the emergence of export pioneers and the subsequent process of diffusion. Finally, they analyze the role played by public institutions. Across sectors, the appearance of a pioneer is largely explained by a knowledge advantage relative to other industry participants regarding foreign markets, which the pioneer acquired previously and independently of his decision to export. Diffusion occurs across as well as within sectors, as pioneers knowledge is relevant to other industries. Since diffusion does not necessarily hurt the pioneer, public policy has a potentially important role in fostering diffusion within and across sectors
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