Search results for "Hunger"
showing 10 items of 1353 documents
Stability of soil microbial structure and activity depends on microbial diversity
2013
Despite the central role of microbes in soil processes, empirical evidence concerning the effect of their diversity on soil stability remains controversial. Here, we addressed the ecological insurance hypothesis by examining the stability of microbial communities along a gradient of soil microbial diversity in response to mercury pollution and heat stress. Diversity was manipulated by dilution extinction approach. Structural and functional stabilities of microbial communities were assessed from patterns of genetic structure and soil respiration after the stress. Dilution led to the establishment of a consistent diversity gradient, as revealed by 454 sequencing of ribosomal genes. Diversity …
16S rDNA analysis for characterization of denitrifying bacteria isolated from three agricultural soils
2000
Bacteria capable of denitrification are spread among phylogenetically diverse groups. In the present investigation, molecular methods (amplified ribosomal DNA restriction analysis (ARDRA) and partial 16S rDNA gene sequencing) were used to determine the genetic diversity of culturable denitrifying soil bacteria. The purpose of this work was to study the microbial density and diversity of denitrifying communities isolated from two luvisols and a rendosol. The denitrifying bacterial density was significantly higher in the two luvisols (3x10(6) and 4x10(6) bacteria g(-1) dry soil) than in the rendosol (4x10(5) bacteria g(-1) dry soil). Denitrifying isolates from soils were grouped according to …
Papel de las leguminosas en la alimentación actual
2010
5 páginas, 2 figuras, 2 tablas.-- et al.
Statistical analysis of sensory profiling data. Graphs for presenting results (PCA and ANOVA)
2000
Abstract A principal component analysis is performed to analyse the matrix of median values, with 16 varieties in rows, and all descriptors in columns. Only texture descriptors contribute to the definition of the main axes. Six varieties are identified that score high on mealiness and low on moisture, the 10 other varieties are ordered according to a mashable axis which involves texture descriptors. Next we exclude texture descriptors since the main characteristics are already found, and mealy varieties since they are not suitable for steamed potatoes. A mixed linear model (ANOVA) with random subject effects is then used for each descriptor. Flavour and taste differences are found among the…
Application of replicated difference testing
2000
International audience; In a recent paper, Brockho and Schlich (1998, Handling replications in discrimination tests. Food Quality and Preference, 9(5), 303±312) proposed a statistically sound way of handling replications in dierence testing. In the present paper, this new test is applied to the data obtained in six experiments on non alcoholic beverages, where triangle tests were intensively replicated (between eight and 60 times) with groups of subjects composed of 12±61 students. The paper aims to estimate in these practical situations the extent to which a group of panelists is heterogeneous towards the ability of detecting a sensory dierence among two products. As the results indicat…
The evolution of lactase persistence in Europe. A synthesis of archaeological and genetic evidence
2012
Lactase persistence, the ability to digest the milk sugar lactose in adulthood, is highly associated with a T allele situated 13,910 bp upstream from the actual lactase gene in Europeans. The frequency of this allele rose rapidly in Europe after transition from hunter–gatherer to agriculturalist lifestyles and the introduction of milkable domestic species from Anatolia some 8000 years ago. Here we first introduce the archaeological and historic background of early farming life in Europe, then summarize what is known of the physiological and genetic mechanisms of lactase persistence. Finally, we compile the evidence for a co-evolutionary process between dairying culture and lactase persisten…
Maternal feeding practices during the first year and their impact on infants' acceptance of complementary food.
2013
Funding: Regional Council of Burgundy + Regional Council of IFR92 + Regional Council of PRNH-INRA-INSERM + Regional Council of the "ANR The French National Research Agency" under the Programme National de Recherche en Alimentation et nutrition humaine (ANR-06-PNRA-028 ) + Regional Council of Bledina, Nestle, Symrise, Cedus and Valrhona; International audience; The introduction of weaning foods is a major transition in the development of infants' eating behavior. Previous studies showed that greater variety at the beginning of the weaning period can later influence an infant's acceptance of new foods. The aim of the present study was to describe maternal feeding practices in the first year (…
Effect of ferritin overexpression in tobacco on the structure of bacterial and pseudomonad communities associated with the roots
2006
The genetic structures of total bacterial and pseudomonad communities were characterized in rhizosphere soil and rhizoplane+root tissues of tobacco wild type and a ferritin overexpressor transgenic line (P6) by a cultivation-independent method using directly extracted DNA at the end of three consecutive plant cultures. The structure of total bacterial communities was characterized by automated ribosomal intergenic spacer analysis (A-RISA), and that of pseudomonad communities was characterized by PCR-restriction fragment length polymorphism (PCR-RFLP) from DNA amplified with specific primers. The structure of total bacterial communities was significantly modified in the rhizosphere soil by t…
Microdiversity of Burkholderiales associated with mycorrhizal and nonmycorrhizal roots of Medicago truncatula
2008
The genetic diversity of bacterial communities associated with mycorrhizal and nonmycorrhizal roots of Medicago truncatula was characterized by two approaches. Firstly, phylogenetic analysis was performed on 164 partial 16S rRNA gene-intergenic spacer (IGS) sequences from operational taxonomic units previously shown to be preferentially associated with mycorrhizal roots. These sequences were distributed into three branches corresponding to Comamonadaceae, Oxalobacteraceae and Rubrivivax subgroups. Most sequences were obtained from mycorrhizal roots, indicating the preferential association of the corresponding families with mycorrhizal roots. A second phylogenetic analysis was performed on t…
Fitness in soil and rhizosphere of Pseudomonas fluorescens C7R12 compared with a C7R12 mutant affected in pyoverdine synthesis and uptake.
2000
International audience; Fluorescent pseudomonads have evolved an efficient strategy of iron uptake based on the synthesis of the siderophore pyoverdine and its relevant outer membrane receptor. The possible implication of pyoverdine synthesis and uptake on the ecological competence of a model strain (Pseudomonas fluorescens C7R12) in soil habitats was evaluated using a pyoverdine minus mutant (PL1) obtained by random insertion of the transposon Tn5. The Tn5 flanking DNA was amplified by inverse PCR and sequenced. The nucleotide sequence was found to show a high level of identity with pvsB, a pyoverdine synthetase. As expected, the mutant PL1 was significantly more susceptible to iron starva…