Potentials in vegetable oils and various nutrients of eighteen varieties of Niger Cucurbitaceae

Citrullus Colocynthis and Lagenaria siceraria are two species of Cucurbitaceae whose seeds are used for the production of dough, cakes and edible oils in Niger. Yield in seeds of 18 varieties belonging to these two species were assessed on the Faculty experimental field. The average berries production was 17 berries per plant the first year in contrast 6 the second year. The best productivity was achieved with Citrullus colocynthis which gave 82 berries per plant the 1st year. The average yield in seeds was 180.15 kg/ha the first year and 704.30 kg/ha the second year. The determination of the physicochemical characteristics showed water, ashes, fat, and protein contents which vary respectively from 7 to 9.50%, 4.13 to 4.84%, 18 to 47% and 11 to 35%. The yield in seeds oil varied from 13.7 to 134 L per ha in the first year and 0.26 liters to 800 L per ha the 2nd year. These are the first studies on Cucurbitaceae which link agronomic and physicochemical characteristics of seeds. They showed very important nutrient contents and oil yield, and even higher than some conventionaloilseeds. Extraction of oils from these seeds could meet the need of the populations.Keywords: Cucurbitaceae, Niger, yield, seeds, oils, food security

Identification of Roles for Peptide: N-Glycanase and Endo-β-N-Acetylglucosaminidase (Engase1p) during Protein N-Glycosylation in Human HepG2 Cells

BACKGROUND: During mammalian protein N-glycosylation, 20% of all dolichol-linked oligosaccharides (LLO) appear as free oligosaccharides (fOS) bearing the di-N-acetylchitobiose (fOSGN2), or a single N-acetylglucosamine (fOSGN), moiety at their reducing termini. After sequential trimming by cytosolic endo beta-N-acetylglucosaminidase (ENGase) and Man2c1 mannosidase, cytosolic fOS are transported into lysosomes. Why mammalian cells generate such large quantities of fOS remains unexplored, but fOSGN2 could be liberated from LLO by oligosaccharyltransferase, or from glycoproteins by NGLY1-encoded Peptide-N-Glycanase (PNGase). Also, in addition to converting fOSGN2 to fOSGN, the ENGASE-encoded cytosolic ENGase of poorly defined function could potentially deglycosylate glycoproteins. Here, the roles of Ngly1p and Engase1p during fOS metabolism were investigated in HepG2 cells. METHODS/PRINCIPAL FINDINGS: During metabolic radiolabeling and chase incubations, RNAi-mediated Engase1p down regulation delays fOSGN2-to-fOSGN conversion, and it is shown that Engase1p and Man2c1p are necessary for efficient clearance of cytosolic fOS into lysosomes. Saccharomyces cerevisiae does not possess ENGase activity and expression of human Engase1p in the png1Delta deletion mutant, in which fOS are reduced by over 98%, partially restored fOS generation. In metabolically radiolabeled HepG2 cells evidence was obtained for a small but significant Engase1p-mediated generation of fOS in 1 h chase but not 30 min pulse incubations. Ngly1p down regulation revealed an Ngly1p-independent fOSGN2 pool comprising mainly Man(8)GlcNAc(2), corresponding to approximately 70% of total fOS, and an Ngly1p-dependent fOSGN2 pool enriched in Glc(1)Man(9)GlcNAc(2) and Man(9)GlcNAc(2) that corresponds to approximately 30% of total fOS. CONCLUSIONS/SIGNIFICANCE: As the generation of the bulk of fOS is unaffected by co-down regulation of Ngly1p and Engase1p, alternative quantitatively important mechanisms must underlie the liberation of these fOS from either LLO or glycoproteins during protein N-glycosylation. The fully mannosylated structures that occur in the Ngly1p-dependent fOSGN2 pool indicate an ERAD process that does not require N-glycan trimming

Agronomic characterization of eighteen cucurbitaceae cultivars used for food in Niger.

Objective: Agronomic potentialities of 18 cucurbitaceous cultivars from two species were assessed in a period of two years on the experimental field of the University Of Niamey Faculty Of Sciences. The experiment was a complete random block. Seventeen (17) cultivars of the Lagenaria siceraria species of which only one species from the Citrullus colocynthis.Methodology and results: Thirteen (13) characteristics were studied. Variance analyses showed that there was very significant difference ( p= 0.05) between cultivars for all studied characteristics, except the duration of the emergence, the date of fructification, the width of the fruit and the weight of the seed the first year. In this way, short-cycle and long cycle cultivars, as well as productive and less productive cultivars are identified. Correlations between the different characteristics showed that the yield in berries is very positively correlated to the weight of a berry (r = 0.76) and the number of seeds per berry (r = 0.61) and negatively with the width (r = - 0.66) and the length (r = -0.73) of a seed. The average production in berries is 17 per plant in the first year against 6 the second year. Better productivity is achieved with Citrullus colocynthis, which gave 82 berries per plant the 1st year. The average yield in seeds was 180.15 kg / ha in the first year and 704.30 kg / ha, in the second year.Conclusion and application of results: Niger cucurbitaceous are unknown and the results of this study show that they have a lot of potentiality and can contribute to achieve the Millennium Development Goals, especially in its food security and fight against poverty programs, since they represent an important source of income for the population.Key words: cucurbitaceous, Citrullus colocynthis, Lagenaria siceraria, agronomic characteristics, Niger

Predictors Generation by Partial Least Square Regression for microwave characterization of dielectric materials

International audienceIn this paper, the microwave characterization of dielectric materials using open-ended coaxial line probe is proposed. The measuring cell is a coaxial waveguide terminated by a dielectric sample. The study consists in extracting the real and imaginary part of the relative dielectric permittivity (ε = ε′-jε'') of the material under test from the measurements of the probe admittance (Ymes(f) = Gmes(f)+jBmes(f)) on a broad band frequency (f between 1 MHz and 1.8 GHz), hence a direct and inverse problems have to be solved. In order to build a database, the direct problem is solved using Finite Elements Method (FEM) for the probe admittance (Y(f) = G(f)+jB(f)). Concerning the inverse problem, Partial Least Square (PLS) Regression (PLSR) is investigated as a fast, simple and accurate inversion tool. It is a dimensionality reduction method which aims to model the relationship between the matrix of independent variables (predictors) X and the matrix of dependant variables (response) Y. The purpose of PLS is to find the Latent Variables (LV) having the higher ability of prediction by projecting original predictors into a new space of reduced dimension. The original inverse model has only three predictors (f, G and B) but is nonlinear, so inspired by the extended X bloc method, more predictors have been created mathematically from the original ones (for example: 1/f2, B/f2, GB, 1/B, G/f, f2G, fG2B, f2G2B2, … etc) in order to take into account the nonlinearity, whence the appellation Predictors Generation Partial Least Square Regression (PG-PLSR). Inversion results of experimental measurements for liquid (ethanol, water) and solid (PEEK (Polyether-ether-ketone)) samples have proved the applicability and efficiency of PG-PLSR in microwave characterization. Moreover, the comparison study in the last section has proved the superiority of PG-PLSR on Multi-Layer Perceptron Neural Network (MLP-NN) in terms of rapidity, simplicity and accuracy

Cracks reconstruction from eddy current testing signals using multi regression SVM

National audienc

Quantum-classical model for the surface plasmon enhanced photoemission process at metal surfaces

The main purpose of this work is to propose a theoretical description of the surface plasmon polariton stimulated electron emission process at metal surfaces in which the primary electron ejection from the conduction band is treated quantum mechanically in order to go beyond the approximate approaches used up to now to represent this first step. Our theoretical results are well supported by experimental energy spectra obtained for some tens of femtosecond laser pulses impinging on a gold grating target at various intensities in the GW/cm 2 range. The present model which allows us to discuss various features of the surface plasmon photoemission process such as the role of the surface plasmon phase is rather simple and could be applied with slight modifications to study the stimulated photoemission of metallic nanoparticles which has been a subject of growing interest during the past few years

Differential incorporation of fish-oil eicosapentaenoate and docosahexaenoate into lipids of lipoprotein fractions as related to their glyceryl esterification : a short-term (postprandial) and long-term study in healthy humans

International audienc