232 research outputs found
L'étalon-or des évaluations randomisées : du discours de la méthode à l'économie politique
La dernière décennie a vu l'émergence d'un nouveau champ de recherche en économie du développement : les méthodes expérimentales d'évaluation d'impacts par assignation aléatoire. Cet article explore le contraste entre d’une part les limites (nombreuses) et la circonscription (très étroite) du champ réel d'application de ces méthodes et d’autre part leur succès, attesté à la fois par leur nombre et leur forte médiatisation. L’analyse suggère que ce contraste est le fruit d’une conjonction économique et politique particulière, émanant de stratégies novatrices de la part des chercheurs de cette nouvelle école, et d’intérêts et de préférences spécifiques provenant à la fois du monde académique et de la communauté des donateurs
Informal versus formal : a panel data analysis of earnings gaps in Madagascar
In spite of its predominant economic weight in developing countries, little is known about informal sector
income dynamics vis-à-vis the formal sector. Some works have been done in this field using household
surveys, but they only consider some emerging Latin American countries (Argentina, Brazil, Colombia and
Mexico; Gong et al., 2004; Perry et al., 2007; Bargain and Kwenda, 2011) and more recently South Africa,
Ghana and Tanzania for Africa (Falco et al., 2010) and Vietnam for Asia (Nguyen et al., 2011). As a matter of
consequence, there is still no way to generalize the (diverging) results to very poor part of the developing
world. Taking advantage of the rich 1-2-3 Surveys dataset in Madagascar, in particular its four waves panel
data (2000, 2001, 2003 and 2004), we assess the magnitude of various formal/informal sector earnings gaps
while addressing heterogeneity issues at three different levels: the worker, the job (wage employment vs. selfemployment)
and the earnings distribution. The questions asked are the following: Is there an informal sector
job earnings penalty? Do some informal sector jobs provide pecuniary premiums? Which ones? Do possible
gaps vary along the earnings distribution? Standard earnings equations are estimated at the mean and at various
conditional quantiles of the earnings distribution. In particular, we estimate fixed effects quantile regressions to
control for unobserved individual characteristics, focusing particularly on heterogeneity within both the formal
and informal sector categories. Our results suggest that the informal sector earnings gap highly depends on the
workers’ job status and on their relative position in the earnings distribution. Penalties may in some cases turn
into premiums. By comparing our results with studies in other developing countries, we draw conclusions
highlighting the Madagascar’s labour market specificity.no
Advanced Concrete Steam Accumulation Tanks for Energy Storage for Solar Thermal Electricity
Steam accumulation is one of the most effective ways of thermal energy storage (TES) for the solar thermal energy (STE) industry. However, the steam accumulator concept is penalized by a bad relationship between the volume and the energy stored; moreover, its discharge process shows a decline in pressure, failing to reach nominal conditions in the turbine. From the economic point of view, between 60% and 70% of the cost of a steam accumulator TES is that of the pressure vessel tanks (defined as US$/kWhth). Since the current trend is based on increasing hours of storage in order to improve dispatchability levels in solar plants, the possibility of cost reduction is directly related to the cost of the material of pressure vessels, which is a market price. Therefore, in the present paper, a new design for steam accumulation is presented, focusing on innovative materials developed specifically for this purpose: two special concretes that compose the accumulation tank wall. Study of dosages, selection of materials and, finally, scale up on-field tests for their proper integration, fabrication and construction in prototype are the pillars of this new steam accumulation tank. Establishing clear and precise requirements and instructions for successful tank construction is necessary due to the highly sensitive and variable nature of those new concrete formulations.The research leading to these results has received funding from CDTI in the project Innterconecta Thesto (ITC-20111050). The work is partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER)). This work was partially funded by the Ministerio de Ciencia, Innovación y Universidades de España (RTI2018-093849-B-C31—MCIU/AEI/FEDER, UE) and by the Ministerio de Ciencia, Innovación y Universidades—Agencia Estatal de Investigación (AEI) (RED2018-102431-T). This work is partially supported by ICREA under the ICREA Academia programme.
Acknowledgments
The authors would like to thank all the Chirivo Construcciones, Hormigones Aznalcóllar, Elabora, Azcatec, Next Force Engineering, Universidad de Granada, Aidico, Centro Andaluz de Metrología, AICIA and Abengoa teams involved in Solúcar Platform during prototype construction and start-up. Cabeza would like to thank the Catalan Government for the quality accreditation given to her research group GREiA (2017 SGR 1537). GREiA is a certified agent TECNIO in the category of technology developers from the Government of Catalonia
Directional control of weakly localized Raman from a random network of fractal nanowires
Disordered optical media are an emerging class of materials capable of
strongly scattering light. Their study is relevant to investigate transport
phenomena and for applications in imaging, sensing and energy storage. While
such materials can be used to generate coherent light, their directional
emission is typically hampered by their very multiple scattering nature. Here,
we tune the out-of-plane directionality of coherent Raman light scattered by a
fractal network of silicon nanowires. By visualizing Rayleigh scattering,
photoluminescence and weakly localized Raman light from the random network of
nanowires via real-space microscopy and Fourier imaging, we gain insight on the
light transport mechanisms responsible for the material's inelastic coherent
signal and for its directionality. The possibility of visualizing and
manipulating directional coherent light in such networks of nanowires opens
venues for fundamental studies of light propagation in disordered media as well
as for the development of next generation optical devices based on disordered
structures, inclusive of sensors, light sources and optical switches
Seasonality and Prevalence of Leishmania major Infection in Phlebotomus duboscqi Neveu-Lemaire from Two Neighboring Villages in Central Mali
Phlebotomus duboscqi is the principle vector of Leishmania major, the causative agent of cutaneous leishmaniasis (CL), in West Africa and is the suspected vector in Mali. Although found throughout the country the seasonality and infection prevalence of P. duboscqi has not been established in Mali. We conducted a three year study in two neighboring villages, Kemena and Sougoula, in Central Mali, an area with a leishmanin skin test positivity of up to 45%. During the first year, we evaluated the overall diversity of sand flies. Of 18,595 flies collected, 12,952 (69%) belonged to 12 species of Sergentomyia and 5,643 (31%) to two species of the genus Phlebotomus, P. duboscqi and P. rodhaini. Of those, P. duboscqi was the most abundant, representing 99% of the collected Phlebotomus species. P. duboscqi was the primary sand fly collected inside dwellings, mostly by resting site collection. The seasonality and infection prevalence of P. duboscqi was monitored over two consecutive years. P. dubsocqi were collected throughout the year. Using a quasi-Poisson model we observed a significant annual (year 1 to year 2), seasonal (monthly) and village effect (Kemena versus Sougoula) on the number of collected P. duboscqi. The significant seasonal effect of the quasi-Poisson model reflects two seasonal collection peaks in May-July and October-November. The infection status of pooled P. duboscqi females was determined by PCR. The infection prevalence of pooled females, estimated using the maximum likelihood estimate of prevalence, was 2.7% in Kemena and Sougoula. Based on the PCR product size, L. major was identified as the only species found in flies from the two villages. This was confirmed by sequence alignment of a subset of PCR products from infected flies to known Leishmania species, incriminating P. duboscqi as the vector of CL in Mali
Current therapy of granulomatosis with polyangiitis and microscopic polyangiitis: the role of rituximab.
Granulomatosis with polyangiitis and microscopic polyangiitis are anti-neutrophil cytoplasmic antibody-associated vasculitides (AAVs) that are prone to cycles of remission and relapse. The introduction of cytotoxic therapy has changed the prognosis for these diseases from typically fatal to manageable chronic illnesses with a relapsing course. Despite improvements in outcomes, recurrence of disease and drug-related toxicity continue to produce significant morbidity and mortality. Better understanding of the pathogenesis of AAV and the mechanism of action of cyclophosphamide has led to investigation of therapies that target B cells. Two randomized controlled trials have shown that rituximab is not inferior to cyclophosphamide for induction of remission in severe AAV, with no significant difference in the incidence of overall adverse events in rituximab- versus cyclophosphamide-treated patients. Data from ongoing clinical trials will determine the role of rituximab in the maintenance of remission
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