Impact of the food safety policies on the reduction of poverty in Tunisian rural areas

The observed trend of decreasing poverty in Tunisian rural areas, where agriculture is still dominated by family and where illiteracy rate and family size are high, questions may be raised about the economic policies adopted by the state. This article puts the analyses of these policies in the framework of food safety issue as food and poverty are tightly related and as food safety objective is multi-sectorial and multi-disciplinary. In economic development plans, food safety objective took the place of self-sufficiency. The analysis of food safety policy is based on a macro-economic analysis of the offer (policies of production pricing and subsidizing, investment policies) and demand (Policies of consumption subsidies and consumer prices) as well as the policies of fight against poverty. This analysis covers two periods: before and after the economic reforms of privatization and liberalization of 1987 (PAS: Structural Adjustment Plan). The assessment of these policies shows that poverty fighting programs are numerous and rich in experiences. These policies are more and more based on assistance programs oriented toward productive actions. The liberalization and privatization efforts were reflected by better performance and competitiveness of the agricultural sector. This had a positive impact on the employment, the migration and the availability of food products in rural areas. The self targeting of the subsidies by differentiating the products reduced the budgetary cost of these transfers and enhanced the equity and the nutritional and food situation of the poor people. The higher increase in income of country people and the decrease of subsidies indicate the more and more use of income direct transfers.Poverty, rural area, structure adjustment, food safety, agricultural and food policies., Food Consumption/Nutrition/Food Safety, Food Security and Poverty,

Self-powered wireless carbohydrate/oxygen sensitive biodevice based on radio signal transmission

peer-reviewedHere for the first time, we detail self-contained (wireless and self-powered) biodevices with wireless signal transmission. Specifically, we demonstrate the operation of self-sustained carbohydrate and oxygen sensitive biodevices, consisting of a wireless electronic unit, radio transmitter and separate sensing bioelectrodes, supplied with electrical energy from a combined multi-enzyme fuel cell generating sufficient current at required voltage to power the electronics. A carbohydrate/oxygen enzymatic fuel cell was assembled by comparing the performance of a range of different bioelectrodes followed by selection of the most suitable, stable combination. Carbohydrates (viz. lactose for the demonstration) and oxygen were also chosen as bioanalytes, being important biomarkers, to demonstrate the operation of the self-contained biosensing device, employing enzyme-modified bioelectrodes to enable the actual sensing. A wireless electronic unit, consisting of a micropotentiostat, an energy harvesting module (voltage amplifier together with a capacitor), and a radio microchip, were designed to enable the biofuel cell to be used as a power supply for managing the sensing devices and for wireless data transmission. The electronic system used required current and voltages greater than 44 mu A and 0.57 V, respectively to operate; which the biofuel cell was capable of providing, when placed in a carbohydrate and oxygen containing buffer. In addition, a USB based receiver and computer software were employed for proof-of concept tests of the developed biodevices. Operation of bench-top prototypes was demonstrated in buffers containing different concentrations of the analytes, showcasing that the variation in response of both carbohydrate and oxygen biosensors could be monitored wirelessly in real-time as analyte concentrations in buffers were changed, using only an enzymatic fuel cell as a power supply.PUBLISHEDpeer-reviewe

Fonctionnalisation de Nanotubes de Carbone pour le Développement de Bio-architectures Affines : Application aux Biocapteurs

The aim of this study is to develop bio-architectures based on single walled carbon nanotubes for electroanalytical applications. For this purpose, different methods of carbon nanotubes functionalization were proposed such as, functionalization in solution, functionalization by dip-coating and by electropolymerization using the π interactions between carbon nanotubes and the π conjugated compounds (pyrrole-biotin, pyrene-biotin, pyrene-adamantane). The used matrixes for the conception of the biosensors are based on the affinity systems between avidin and biotin and that between adamantane and β-cyclodextrin. The comparison of the biosensors performances leads to the determination of the most suitable way for the carbon nanotube functionalization. The latter consists on forming a monomer monolayer by dip-coating reinforced by oxidative polymerization in a monomer free solution. These processes stabilize the adsorbed layer offering an optimum permeation to the underlying electrode. The resulting modified surfaces were characterized by surface physico-chemical analysis.L'objectif de cette étude consiste à développer des bio-architectures à base de nanotubes de carbone mono-feuillet à visées électroanalytiques. Pour ce faire, différentes méthodes de fonctionnalisation de nanotubes de carbone ont été proposées à savoir la fonctionnalisation en solution, par trempage et par électropolymérisation en se servant des interactions π entre les nanotubes de carbone et des molécules π-conjugués (le pyrrole-biotine, le pyrène-biotine et le pyrèneadamantane). Les matrices utilisées pour la conception des biocapteurs sont basées sur les systèmes d'affinité entre l'avidine et la biotine, et entre l'adamantane et la β- cyclodextrine. La comparaison des performances des différents biocapteurs a permis de déterminer la méthode la plus adéquate pour la fonctionnalisation des nanotubes de carbone. Cette dernière consiste à former une monocouche de monomères par simple trempage puis de la renforcer par électropolymérisation oxydative dans une solution exempte de monomère. Cette stabilisation de la couche adsorbée préserve une excellente accessibilité à la surface de l'électrode sous-jacente. Les surfaces fonctionnelles qui en résultent ont été caractérisées par des méthodes physico-chimiques d'analyse

Pyrene functionalized single-walled carbon nanotubes as precursors for high performance biosensors

International audienceThe attachment of biotin to nanotube modified electrodes by formation of π-stacking interactions using a biotinylated pyrene derivative is reported. The specific anchoring of biological macromolecules via avidin bridges was investigated using biotinylated glucose oxidase (GOX-B) as model enzyme. Further studies focus the possibility of the electropolymerization of pyrene derivatives. Four types of biotin-SWCNT modified electrodes were investigated: (1) deposits of biotin-pyrenefunctionalizednanotubes (B-SWCNTs); (2) deposits of regular nanotubes, functionalized by incubation in a biotin-pyrene solution; (3) the latter configuration and subsequent electropolymerization of the adsorbed biotin-pyrene; and (4) deposits of regular nanotubes subsequently modified by electropolymerization of a pyrene-biotin monomer (2 mM). The nanotubes deposits were characterized by SEM imaging and the electropolymerization of the pyrene derivatives were investigated using cyclic voltammetry. These types of biotin-SWCNT modified electrodes were tested due to their capacity to immobilize biotinylated biomolecules (GOX-B) via avidin bridges and their performances in glucose detection were examined using amperometry. The best configuration (3) was obtained with SWCNT coatings modified by specific adsorption and electropolymerization of biotin-pyrene. A maximum current density of 584 μA cm−2 could be realized with a sensitivity of 37 mA M−1 cm−2 for a linear range between 5 μM and 13 mM

In situ synthesis of stable mixed ligand Fe2+ complexes on bipyridinyl functionalized electrodes and nanotube supports

International audienc

Zur Vorhersage der Dauerhaftigkeit von Beton gegenueber Witterungseinfluessen

TIB: FR 1136 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Multiple functionalization of single-walled carbon nanotubes by dip coating

International audienc

Impact of the food safety policies on the reduction of poverty in Tunisian rural areas

The observed trend of decreasing poverty in Tunisian rural areas, where agriculture is still dominated by family and where illiteracy rate and family size are high, questions may be raised about the economic policies adopted by the state. This article puts the analyses of these policies in the framework of food safety issue as food and poverty are tightly related and as food safety objective is multi-sectorial and multi-disciplinary. In economic development plans, food safety objective took the place of self-sufficiency. The analysis of food safety policy is based on a macro-economic analysis of the offer (policies of production pricing and subsidizing, investment policies) and demand (Policies of consumption subsidies and consumer prices) as well as the policies of fight against poverty. This analysis covers two periods: before and after the economic reforms of privatization and liberalization of 1987 (PAS: Structural Adjustment Plan). The assessment of these policies shows that poverty fighting programs are numerous and rich in experiences. These policies are more and more based on assistance programs oriented toward productive actions. The liberalization and privatization efforts were reflected by better performance and competitiveness of the agricultural sector. This had a positive impact on the employment, the migration and the availability of food products in rural areas. The self targeting of the subsidies by differentiating the products reduced the budgetary cost of these transfers and enhanced the equity and the nutritional and food situation of the poor people. The higher increase in income of country people and the decrease of subsidies indicate the more and more use of income direct transfers