Comparative analysis of artisanal and recreational fisheries for Dentex dentex in a Marine Protected Area

The common dentex, Dentex dentex (L.), is an iconic marine coastal fish in the Mediterranean Sea. This study was performed in the Bonifacio Strait Natural Reserve (BSNR), (NW Mediterranean Sea). The aims were to: (1) evaluate temporal variation of the artisanal fishing of common dentex (2000–2012); (2) compare and quantify catch rates, fishing techniques and catch composition for artisanal and recreational fisheries, and determine the influence of management measures by both activities; and (3) estimate the production of both artisanal and recreational fisheries. Fishery data were collected from different artisanal fishing surveys (onboard fishing vessels and landings) and recreational fishing surveys (roving). The gears with the highest rates of exploitation were longline (3554 g per 100 hooks) and Trolling (351 g boat^?1 h^?1 ±SE), respectively, for artisanal and recreational fishing. This study showed that catches by both activities were quantitatively higher in partially protected areas than outside them. Production estimations suggest that the recreational fishery contributes significantly to fishing mortality and that it can magnify the negative effects of artisanal fisheries. Specific measures are needed for the sustainable fishery management of common dentex.     

Influence of long-term organic and mineral fertilization on soil nematofauna when growing Sorghum bicolor in Burkina Faso

Soil degradation has led crop yield to decline in many Sahelian countries and is a fundamental agricultural and economical threat for local populations. In Saria, Burkina Faso, long-term experiments are being performed to find efficient soil management practices that could improve soil fertility. A randomized block experiment comprising organic amendment (unamended control, straw at 8.3 t ha⁻¹, manure at 10 t ha⁻¹) coupled with mineral fertilization (no urea, urea at 60 kg ha⁻¹) was started in 1980 with a continuous sorghum (Sorghum bicolor) cropping system. Twenty-six years after the settlement of the treatments, we compared their effects on nematode populations, community structure, and ecological indices, as well as soil physical and chemical properties at three stages of sorghum’s cropping cycle.     

Carotenoid biosynthetic pathway in the citrus genus: number of copies and phylogenetic diversity of seven genes

The first objective of this paper was to analyze the potential role of allelic variability of carotenoid biosynthetic genes in the interspecific diversity in carotenoid composition of Citrus juices. The second objective was to determine the number of copies for each of these genes. Seven carotenoid biosynthetic genes were analyzed using restriction fragment length polymorphism (RFLP) and simple sequence repeats (SSR) markers. RFLP analyses were performed with the genomic DNA obtained from 25 Citrus genotypes using several restriction enzymes. cDNA fragments of Psy, Pds, Zds, Lcy-b, Lcy-e, Hy-b, and Zep genes labeled with [alpha-(32)P]dCTP were used as probes. For SSR analyses, two primer pairs amplifying two SSR sequences identified from expressed sequence tags (ESTs) of Lcy-b and Hy-b genes were designed. The number of copies of the seven genes ranged from one for Lcy-b to three for Zds. The genetic diversity revealed by RFLP and SSR profiles was in agreement with the genetic diversity obtained from neutral molecular markers. Genetic interpretation of RFLP and SSR profiles of four genes (Psy1, Pds1, Lcy-b, and Lcy-e1) enabled us to make inferences on the phylogenetic origin of alleles for the major commercial citrus species. Moreover, the results of our analyses suggest that the allelic diversity observed at the locus of both of lycopene cyclase genes, Lcy-b and Lcy-e1, is associated with interspecific diversity in carotenoid accumulation in Citrus. The interspecific differences in carotenoid contents previously reported to be associated with other key steps catalyzed by PSY, HY-b, and ZEP were not linked to specific alleles at the corresponding loci.     

Atrazine mineralization in bulk soil and maize rhizosphere

An experiment was carried out in the greenhouse in order to compare atrazine mineralization in bulk soil and maize rhizosphere at different development stages. After 4, 8 and 12 weeks, we have (1) measured the soil microbial biomass C, (2) characterized the C substrate utilization profiles of the culturable microflora, and (3) analyzed atrazine mineralization. Microbial growth was stimulated in planted soil and different C substrate utilization patterns were obtained in bulk and rhizosphere soils during the first 2 months. During this period, laboratory tests for atrazine biodegradation revealed a lower mineralization potential in bulk than in planted soil. Atrazine mineralization was stimulated to a greater extent after atrazine application in the greenhouse but again the presence of plants had a favorable effect. After 12 weeks of cropping, the atrazine mineralization potential decreased in planted soil with or without prior atrazine application.     

Convenient synthesis of 2,4-diacetylphloroglucinol, a natural antibiotic involved in the control of take-all disease of wheat

2,4-Diacetylphloroglucinol (DAPG) is an antibiotic with broad-spectrum antibacterial and antifungal activities. It is a major determinant in the biological control of several plant diseases. DAPG is produced by Pseudomonas fluorescens both in vitro and in the rhizosphere of wheat. It is involved in the natural suppression of take-all disease known as take-all decline, which develops in soils following extended monoculture of wheat or barley. A one-step synthesis of DAPG from the commercially available 2-acetylphloroglucinol is described. This reaction involves the direct alkylation of 2-acetylphloroglucinol using acetic anhydride as the acetylation reagent, with boron trifluoride-etherate as the catalyst. This synthesis is simple and produces higher yields of DAPG (90%) as compared with previously described procedures. As ecological concerns are gaining equal status with agricultural concerns, the demand for natural biocontrol measures is increasing. There is tremendous pressure from society on agriculture to reduce the use of pesticides. A discussion is given on the agricultural and ecological importance of this natural antibiotic and its application as an alternative to reduce the use of synthetic pesticides.     

Effects of nucleo-cytoplasmic interactions on leaf volatile compounds from citrus somatic diploid hybrids

Three diploid citrus somatic hybrids (cybrids) were produced by fusions combining nucellar callus-derived protoplasts of Willow Leaf mandarin (Citrus deliciosa Ten.) and Commune clementine (Citrus clementina Hort. ex Tan.) with, respectively, leaf protoplasts of Eureka lemon [Citrus limon (L.) Burm.] and Marumi kumquat [Fortunella japonica (Thunb.) Swing.] and leaf protoplasts of Marumi kumquat. Ploidy and origins of the nuclear, chloroplastic, and mitochondrial genomes were investigated by flow cytometry and nuclear and cytoplasmic simple sequence repeat analyses. Volatile compounds were extracted from the leaves of the three cybrids by a pentane/ether (1:1) mixture, analyzed by GC-MS, and compared to those of their parents. The cybrids were found to be very close to their nucleus-giving parent, suggesting that the main information for volatile compounds biosynthesis is contained in the nucleus. However, nucleo-cytoplasmic interactions occurred: the (mandarin + lemon) cybrid, possessing nucleus and chloroplasts of lemon and mitochondria from mandarin, synthesizes more monoterpene alcohols and esters than its nucleus-giving parent; the (clementine + kumquat) cybrid, possessing nucleus from kumquat and organelles from mandarin, synthesizes more monoterpene and sesquiterpene hydrocarbons and sesquiterpene alcohols than its nucleus-giving parent.     

Toward a kinetic model for acrylamide formation in a glucose-asparagine reaction system

A kinetic model for the formation of acrylamide in a glucose-asparagine reaction system is pro-posed. Equimolar solutions (0.2 M) of glucose and asparagine were heated at different temperatures (120-200 degrees C) at pH 6.8. Besides the reactants, acrylamide, fructose, and melanoidins were quantified after predetermined heating times (0-45 min). Multiresponse modeling by use of nonlinear regression with the determinant criterion was used to estimate model parameters. The proposed model resulted in a reasonable estimation for the formation of acrylamide in an aqueous model system, although the behavior of glucose, fructose, and asparagine was slightly underestimated. The formation of acrylamide reached its maximum when the concentration of sugars was reduced to about 0. This supported previous research, showing that a carbonyl source is needed for the formation of acrylamide from asparagine. Furthermore, it is observed that acrylamide is an intermediate of the Maillard reaction rather than an end product, which implies that it is also subject to a degradation reaction.     

Redox conditions and heavy metals distribution in mangrove forests receiving effluents from shrimp farms (Teremba Bay,New Caledonia)

Purpose  

The mangroves of New Caledonia, in the south Pacific, act as a buffer between a lagoon of more than 20,000 km² and the island, which is characterized by ultramafic rocks and lateritic soils that are exploited for their richness in heavy metals. We will provide a better understanding of the redox conditions, and of heavy metal distributions in mangroves receiving shrimp farm effluents.     

Effects of Municipal Sewage Sludge Application on Soil and Purple Moor-grass (Molinia caerulea) Contamination by Metals in a Maritime Pine Forest

Granular bentonite has been assessed regarding its capacity to remove Hg(II), Cd(II) and Pb(II) from aqueous solutions. Sorption capacities, kinetics and the dependence of the sorption process on pH were determined. Fractional power, pseudo-first-order, pseudo-second-order and intra-particle diffusion equations were used to model the kinetics of metal adsorption. The pseudo-second-order model showed the best fit to experimental data. Different two-parameter sorption isotherm models (Langmuir, Freundlich, Temkin and Dubinin?CRadushkevich) were used to fit the equilibrium data. Freundlich's isotherm model gave the best fit to experimental data. The selectivity of granular bentonite towards these metals is Pb(II)?>?Cd(II)?>?Hg(II). The adsorption capacities of granular bentonite towards the metals expressed in milligramme metal per gramme granular bentonite are 19.45, 13.05 and 1.7 for Pb(II), Cd(II) and Hg(II), respectively (for an initial concentration of 100 mg metal/L).