Stockage de carbone et flux de gaz à effet de serre en prairie (synthèse bibliographique)

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(1), 103-117

Grassland carbon (C) sequestration can play an important role in mitigating total greenhouse gas (GHG) emissions of livestock production systems. An accurate inventory of livestock production system ... [more ▼]

Grassland carbon (C) sequestration can play an important role in mitigating total greenhouse gas (GHG) emissions of livestock production systems. An accurate inventory of livestock production system contribution to GHG emissions requires to think in terms of global budget, by considering both the GHG sources and the mitigation potential trough grassland soil carbon sequestration. There is a huge variability in C and GHG balances of grasslands that is mainly due to management practices and climatic conditions. The present article shows that, to reduce the uncertainties of the results, long term measurements at the field scale are necessary. Also, it shows the importance of taking the fluxes of the three main GHGs (carbon dioxide, nitrous oxide, methane) into account when calculating the GHG budget. This article also highlights the need for a better understanding of the mechanisms driving the fluxes, in relation to environmental factors and management practices, in order to propose mitigation strategies able to enhance soil carbon sequestration in soils and to reduce methane and nitrous oxide emissions. [less ▲]

Preserved automatic inhibition effect after 1 Hz repetitive transcranial magnetic stimulation over the supplementary motor area

Poster (2013)

Background: It is widely accepted that medial frontal regions are involved in voluntary action control. Indeed, Sumner et al. (2007) have recently suggested that one of the mechanisms through which the ... [more ▼]

Background: It is widely accepted that medial frontal regions are involved in voluntary action control. Indeed, Sumner et al. (2007) have recently suggested that one of the mechanisms through which the supplementary motor area (SMA) contributes to voluntary control is automatic and unconscious motor inhibition. In this study, they administered a visuo-motor subliminal masked prime task (Eimer & Schlaghecken, 2003) to two patients with micro-lesions of the SMA and demonstrated an absence of automatic and unconscious inhibition as evoked by masked prime stimuli. This finding has been supported by neuroimaging data (D'Ostilio et al., 2012). Here, the aim of our research was to corroborate this result by means of a “virtual lesion” approach. Methods: For this purpose, we examined the effects of 1 Hz rTMS (train of 20 min; stimulus intensity 120 % of resting motor threshold) over the SMA of ten healthy volunteers, previously localized by functional magnetic resonance imaging (fMRI), on reaction time (RT) performance in the subliminal masked prime task. The functional localizer experiment consisted of four blocks of sequential finger tapping and 15 s of rest after each block. Imaging data were analyzed with SPM 8 and then were imported into the Brainsight software version 2.1.5. With such system, we were able to navigate across the subjects’ brain. The peak voxel in the SMA for each subject (at a statistical threshold of p < 0.05 uncorrected) was used as a target point for the rTMS session. Results: The mean motor threshold was 50.9 % of maximal stimulator output (SD: ± 4.86 %). Wilcoxon tests showed a significant effect of compatibility on RTs (sham: Z = 2.7, p = 0.007; rTMS: Z = 2.8, p = 0.005) and accuracy rate (sham: Z = 2.5, p = 0.01; rTMS: Z = 2.1, p = 0.03), subjects being slower and making more errors in compatible trials (sham: 391.64 ± 52 ms, 87.3 % of accuracy; rTMS: 396.66 ± 37 ms, 86.3 % of accuracy) in comparison to incompatible trials (sham: 357.45 ± 36 ms, 92.5 % of accuracy; rTMS: 356.25 ± 28 ms, 92.7 % of accuracy), suggesting motor inhibition. However, this NCE was preserved after rTMS over the SMA (RTs: Z = 0.87, p = 0.39; accuracy rate: Z = 0.71, p = 0.47). Conclusions: We conclude that long trains of low intensity 1 Hz rTMS did not affect the modulation of RT by subliminal stimuli, suggesting that the SMA might not be mandatory for the implementation of this automatic process. The limitation of this study is relative to the neural efficacy argument because we are not sure that TMS was strong enough to disturb the redundant organizational processing in the SMA or that other regions were not able to compensate for the virtually lesioned area. [less ▲]

Reproductive and productive performances of the stress-negative Piétrain pigs in the tropics: the case of Vietnam

in Animal Production Science (2013), 53(2), 173-179

The objective of the present study is to investigate the reproduction, production and semen traits of the stressnegative Piétrain line of pigs in the north of Vietnam, as well as to identify various ... [more ▼]

The objective of the present study is to investigate the reproduction, production and semen traits of the stressnegative Piétrain line of pigs in the north of Vietnam, as well as to identify various factors (halothane genotype, generationorigin, parity, sex and month of the year) acting on these traits. The experiment was carried out on a purebred nucleus on Dong Hiep farm, Haiphong province in Vietnam. The reproduction performances and the sperm quality measures were based on 12 sows and 5 boars imported from Belgium as well as on 29 sows and 14 boars born in Vietnam, while the production performances were recorded only from 251 animals born in Vietnam. No significant differences were observed between halothane genotypes of sows for reproduction traits (P>0.0578). At the age of 7.5 months, bodyweight, backfat thickness and longissimus depth (7.5) of homozygous-dominant pigs were higher (P<0.05) than in heterozygotes. Homozygous-dominant boars had higher total number of spermatozoa than heterozygote boars (P < 0.05); similarly, Vietnam boars also presented higher total number of spermatozoa values than Belgium boars (P < 0.001). Vietnam sows had longer duration of pregnancy, more piglets born alive and heavier litter weight of weaning than Belgium sows (P < 0.01). Bodyweight at birth, at weaning, at 2, 5.5 and 7.5 months of age increased from the first to third parity (P < 0.05). Gilts had more lean meat than intact boars (P < 0.01). Compared with observations made in temperate countries, the reproduction and production performances, sperm concentration and total number of spermatozoa of stress-negative Piétrain pigs were reduced, whereas lean meat percentage was not affected. This might be due to the different climate, although improving values for animals born in Vietnam might indicate adaptation of the animals and/or of the technicians with that breed. The results support the interest of the use of this new Piétrain line in tropical countries with ecological and climatic conditions similar to Vietnam. [less ▲]

Hydrolysis of starches and flours by sorghum malt amylases for dextrins production

in European Food Research & Technology (2013)

Corn and wheat starches as well as wheat and cassava flours were hydrolyzed using sorghum malt at 65 °C for 6 hours. During these reactions, dextrose equivalent (DE) values were followed under 3 ... [more ▼]

Corn and wheat starches as well as wheat and cassava flours were hydrolyzed using sorghum malt at 65 °C for 6 hours. During these reactions, dextrose equivalent (DE) values were followed under 3 concentrations of sorghum malt and of calcium chloride. Wheat flour presented the highest DE values and cassava flour had the highest hydrolysis yield. Thus, different dextrins were produced in a pilot plant and were analyzed by HPSEC and HPAEC-PAD for their molecular weight distribution and oligosaccharides composition respectively. The results indicated that oligosaccharides with broad molecular weight distributions were present in the dextrins produced and that the proportion of maltose was very high. [less ▲]

Flow-cytometric assessment of damages to Acetobacter senegalensis during freeze-drying process and storage

in Acetic Acid Bacteria (2013)

Downstream processes have great influences on bacterial starter production. Different modifications occur to cellular compounds during freeze-drying process and storage of bacterial starters. Consequently ... [more ▼]

Downstream processes have great influences on bacterial starter production. Different modifications occur to cellular compounds during freeze-drying process and storage of bacterial starters. Consequently, viability and culturability (multiplication capacity) undergo some changes. In this study, the effects of freeze-drying process and storage conditions were examined on cell envelope integrity, respiration and culturability of Acetobacter senegalensis. Freezing of cells protected with mannitol (20% w/w) did not affect cell multiplication and respiration considerably; however, 19% of cells showed compromised cell envelope after freezing. After drying, 1.96×1011 CFU/g were enumerated, indicating that about 34% of the cells could survive and keep their culturability. Drying of the cells induced further leakage in cell envelope and finally 81% of cells appeared as injured ones; however, 87% of the dried cells maintained their respiration capacity. Storage temperature had significant effect on cell multiplication ability; higher storage temperature (35°C) caused 8.59-log reduction in cell culturability after nine-month period of storage. Collapse of cell envelop integrity and respiration was observed at 35°C. At lower storage temperature (4°C), the culturability decreased about one-log reduction after nine months. Cell envelope integrity was subjected to minor changes during a period of nine month-storage at 4°C whereas a heterogeneous population of cells with different respiration capacity emerged at 4°C. These results indicate that a major part of cells undergone drying process and storage entered into viable but non-culturable state. In addition, usage of different culture media didn’t improve resuscitation. Besides, it seems that sub-lethal damages to cell envelope caused uptake of propidium iodide, however these kinds of injuries could not impress cell multiplications and respiration. [less ▲]

Inventaire des archives de la famille Nagelmackers

Report (2013)

Mobility and distribution of lead, cadmium, copper and zinc in soil profiles in the peri-urban market garden of Kunming, Yunnan Province, China

in Archives of Agronomy and Soil Science (2013)

Toward genomic prediction from whole-genome sequence data: impact of sequencing design on genotype imputation and accuracy of predictions.

in Heredity (2013)

Genomic prediction from whole-genome sequence data is attractive, as the accuracy of genomic prediction is no longer bounded by extent of linkage disequilibrium between DNA markers and causal mutations ... [more ▼]

Genomic prediction from whole-genome sequence data is attractive, as the accuracy of genomic prediction is no longer bounded by extent of linkage disequilibrium between DNA markers and causal mutations affecting the trait, given the causal mutations are in the data set. A cost-effective strategy could be to sequence a small proportion of the population, and impute sequence data to the rest of the reference population. Here, we describe strategies for selecting individuals for sequencing, based on either pedigree relationships or haplotype diversity. Performance of these strategies (number of variants detected and accuracy of imputation) were evaluated in sequence data simulated through a real Belgian Blue cattle pedigree. A strategy (AHAP), which selected a subset of individuals for sequencing that maximized the number of unique haplotypes (from single-nucleotide polymorphism panel data) sequenced gave good performance across a range of variant minor allele frequencies. We then investigated the optimum number of individuals to sequence by fold coverage given a maximum total sequencing effort. At 600 total fold coverage (x 600), the optimum strategy was to sequence 75 individuals at eightfold coverage. Finally, we investigated the accuracy of genomic predictions that could be achieved. The advantage of using imputed sequence data compared with dense SNP array genotypes was highly dependent on the allele frequency spectrum of the causative mutations affecting the trait. When this followed a neutral distribution, the advantage of the imputed sequence data was small; however, when the causal mutations all had low minor allele frequencies, using the sequence data improved the accuracy of genomic prediction by up to 30%.Heredity advance online publication, 3 April 2013; doi:10.1038/hdy.2013.13. [less ▲]

Art on the lagoon: Eliasson at the Biennale of Venice

in Newman, Conor; Nussaume, Yann; Pedroli, Bas (Eds.) Landscape and Imagination. Towards a new baseline for education in a changing world (2013)

The Biennales of Venice are not limited to exhibitions in national pavilions. Every year artists and architects choose to confront the site and more specifically, the lagoon. In the edition of 2005, the ... [more ▼]

The Biennales of Venice are not limited to exhibitions in national pavilions. Every year artists and architects choose to confront the site and more specifically, the lagoon. In the edition of 2005, the artist O. Eliasson proposed an installation (Your black horizon, 2005) where the visitors left the wide expanse and intense light of the lagoon to enter a darkened enclosed space with subtle light effects. These aesthetic experiences enhanced the visitors’ perception of light by changing the usual spatiality and temporality of colour. We will analyze the role of memory in the rite of the visit, and look at how the museal strategies of the artist create a play with spatial memory and sense of orientation in relation to the outdoor space of the lagoon. [less ▲]

La tolérance est coûteuse. On essaye l'intolérance ?

E-print/Working paper (2013)

Le texte a servi à présenter une conférence à des étudiants de bacheliers pédagogiques. Il rappelle, sur un ton informel, mais en essayant d'être rigoureux, la place et l'importance de la tolérance dans ... [more ▼]

Le texte a servi à présenter une conférence à des étudiants de bacheliers pédagogiques. Il rappelle, sur un ton informel, mais en essayant d'être rigoureux, la place et l'importance de la tolérance dans toute conception raisonnable de la vie en société. Il rappelle notamment que si la tolérance n'est pas une vertu "flamboyante", elle constitue un préalable indispensable à d'autres modalités plus exigeantes du vivre ensemble [less ▲]