Pointwise adaptive estimation for robust and quantile regression

A nonparametric procedure for robust regression estimation and for quantile regression is proposed which is completely data-driven and adapts locally to the regularity of the regression function. This is achieved by considering in each point M-estimators over different local neighbourhoods and by a local model selection procedure based on sequential testing. Non-asymptotic risk bounds are obtained, which yield rate-optimality for large sample asymptotics under weak conditions. Simulations for different univariate median regression models show good finite sample properties, also in comparison to traditional methods. The approach is extended to image denoising and applied to CT scans in cancer research

Concurrence Fiscale, Mode De Financement De La Croissance Basé Sur Le Capital Étranger Et Qualité De La Redistribution Du Revenu Au Cameroun

The objective of this article is to analyse the social and economic effectiveness of a mode of financing development based on foreign direct investment To this end a careful and endoscopic observation of the recent economic literature has enabled us to see that FDI through the mechanisms of the fiscal competition it generates between States could in one way or another affect the socio-economic tax and even redistributive variables of a host country Thus using the VAR modelling in this article we realized that these foreign capital flows have a mixed effect on the quality of income redistribution in Cameroo

VERTICALIZAÇÃO AGROINDUSTRIAL E GESTÃO COOPERATIVISTA: EM BUSCA DE SUBSÍDIOS PARA ESTRATÉGIAS PRODUTIVAS E COMERCIAIS NA AGRICULTURA FAMILIAR

A pesquisa na qual se baseia o presente trabalho está em andamento em Quissamã, município do Estado do Rio de Janeiro e procura comparar financeiramente possíveis alternativas de negócio agroindustrial na cadeia do coco da região. O objetivo do trabalho é examinar os resultados preliminares da pesquisa no sentido de identificar elementos de estratégias produtivas e comerciais para o fortalecimento da agricultura familiar. O caso em estudo é a Cooperativa Mista de Produtores Rurais de Quissamã. A pesquisa está sendo realizada com base no método de Diagnóstico Rural Rápido. A partir dos dados coletados, constata-se que a verticalização agroindustrial por meio da cooperativa é um mecanismo capaz de ajudar a agricultura familiar a aproveitar eficientemente de seus recursos. Espera-se gerar, no final da execução da pesquisa, informações referentes às características da verticalização agroindustrial, à dinâmica da gestão cooperativista e aos requisitos do fortalecimento da agricultura familiar.----------------------------------------------The research on which this work is based is in execution in Quissamã, city of the State of Rio de Janeiro and seeks to financially compare possible alternatives of agroindustrial business in the chain of the coconut of the region. The objective of the work is to examine the preliminary results of the research in the direction to identify elements of productive and commercial strategies for the reinforcement of family agriculture. The case in study is the Mixed Cooperative of Agricultural Producers of Quissamã. The research is being realized on the basis of the method of Rapid Rural Appraisal. From the collected data, one notes that the agro-industrial verticalization by means of the cooperative is a mechanism able to help the family farmers to efficiently use their resources. One expects to generate, in the end of the execution of the research, information relative to the characteristics of the agro-industrial verticalization, to the dynamics of the cooperativist management and to the requirements of the reinforcement of family agriculture.Cooperative, Vertical integration, Chain of the coconut, Cooperativa, Integração vertical, Cadeia do coco, Agribusiness, Industrial Organization,

BIOMARKERS RELEVANT TO OIL AND GAS INDUSTRIAL ACTIVITIES IN LOW TEMPERATURE MARINE ECOSYSTEMS

Because of its geographical location, the Arctic environment is considered as pristine. However, expanding industrial activities in the Arctic require assessment of the toxicity of chemicals at low temperature. Biomarkers defined as "biological responses to a chemical or chemicals that give a measure of exposure or toxic effect" were shown to be relevant to measure in situ impact of oil discharges. Most biomarker studies have been performed with temperate organisms. The Arctic is characterised by low stable temperature, strong seasonality in light, resulting in a short primary production in Spring. Therefore, indigenous organisms have developed specific adaptations to live with a hmited food supply in water near freezing point. Conversely, physical properties of petroleum hydrocarbons are affected by low temperature (i.e. reduced solubility). Consequently, the biological adaptation of cold-water organisms together with the altered oil behaviour, may affect typical biomarker responses. Because oil compounds are strongly prooxidant, the research strategy of this work was based on oxidative stress. The antioxidant defences were investigated by measuring the total oxyradical scavenging capacity (TOSC). The impact of reactive oxygen species was investigated by measuring the stability of the cell membranes. Finally, the physiology of the organisms was considered by looking at heart and respiration rates. Invertebrates were selected for study owing to their abundance in the polar ecosystem. They were sampled using dredges and Scuba diving from the research vessel Jan Mayen (University of Tromso) in May and August 1999, and during May and September 2000 in the l^ords of Svalbard and in Antarctica as well in January 2000. In the Arctic, two bivalves, Mya tnincata and Chlamys islandicus, and two crustaceans, Hyas araneus and Sclerocrangon boreas were selected. In this work, the ecophysiology of Arctic and Antarctic marine invertebrates was investigated and compared to temperate organisms. Polar marine invertebrates are characterised by low respiration and heart rates and a high TOSC. The elevated level of antioxidant defences is thought to reflect the oxidative pressure of the polar marine ecosystem; however, it suggested that a high TOSC may help to protect biomolecules from oxidative damage as repair mechanisms are limited due to the lack of food for 9 months. Organisms were exposed to poly aromatic hydrocarbons either dissolved, dispersed injected or via sediment. TOSC, cell membrane stabiHty and heart rate were valid biomarkers to monitor the impact of poly aromatic hydrocarbons in Arctic marine organisms. The biomarker responses obtained in this study provide essential background information for monitoring the potential impact of oil and gas activities in the Arctic.Faculty of Science; Akvamilj

Les Technologies De L Information Et De La Communication (TIC) Promeuvent-Elles L Inclusion Financiere En Afrique Sub-Saharienne ? Do Information And Communication Technologies (ICTs) Promote Financial Inclusion In Sub-Saharan Africa?

The objective of this paper is to assess the effect of ICTs on financial inclusion in Sub-Saharan African countries The main contribution of this work lies in the application of Rogers 2003 theory of diffusion of innovation to the explanation of access to financial services and the introduction of the financial inclusion index that we develop following the work of Sethy 2016 The methodology is based on the fixedeffect model inspired by the modified version of the Gompertz innovation diffusion model introduced by Chow 1983 and revised by Rogers 2003 The sample includes 33 SSA countries and the study period is 2004-2017 The empirical analysis leads to the results that on the one hand mobile phones and the internet have a positive and significant effect on financial inclusion and on the other hand fixed phones negatively and significantly affect accessibility to financial service

The Effect of Education on Tendency of Demand for Maternal Health Care Services in Cameroon

The objective of this study is to show the effect of Education on tendency of demand for maternal health care services in Cameroon This study is based on data from health and demographic survey using multiple indicators realized in Cameroon in 2004 and 2011 It is based on many statistical tests and economic models the analysis of decomposition multinomial regressions to explain and understand of this effect The results obtained can be summarized as follows At the descriptive level the decomposition analysis reveals that between 2004 and 2011 the proportion of women who have demanded prenatal health care services delivery services according to the level of education has dropped lightly dropped with 3 and 4 respectively meanwhile within the same period the proportion of women who have demanded postnatal health services according to the level of education has increased by 8 The explanatory analysis reveals that the educational level of the woman has a significant effect on the demand for maternal health care service

Inadéquations Éducatives Et Transition Vers Le Marché Du Travail Au Cameroun

Along with labor market rigidity and barriers to occupational mobility educational mismatch is one of the most costly factors in labor markets The relationship between educational mismatch and the labor market is increasingly a major concern of education and labor economists This phenomenon which was once evident in developed countries is now more evident in developing countries particularly in Cameroon It is in light of this disturbing reality that this study seeks to understand the effect of educational mismatches on the transition of graduates to the labor market in Cameroon Thus we apply the Competing risk regression method to data from the fourth Cameroonian Household Survey ECAM IV The general result of this analysis is that mismatch risks increase the duration of unemployment i e they negatively impact the transition of graduates to the labor market Taking into account the endogeneity of mismatches the econometric results show that educational mismatch risks increase the duration of unemploymen