A Forward Genetic Screen Identifies Mutants Deficient for Mitochondrial Complex I Assembly in Chlamydomonas Reinhardtii.

in Genetics (2011)

Mitochondrial Complex I is the largest multimeric enzyme of the respiratory chain. The lack of a model system with facile genetics has limited the molecular dissection of Complex I assembly. Using ... [more ▼]

Mitochondrial Complex I is the largest multimeric enzyme of the respiratory chain. The lack of a model system with facile genetics has limited the molecular dissection of Complex I assembly. Using Chlamydomonas reinhardtii as an experimental system to screen for Complex I defects, we isolated, via forward genetics, amc1 to 7 nuclear mutants (for assembly of mitochondrial complex I) displaying reduced or no Complex I activity. BN-PAGE and immunoblot analyses revealed that amc3 and amc4 accumulate reduced levels of the Complex I holoenzyme (950 kDa) while all other amc mutants fail to accumulate a mature complex. In amc1, 2, 5, 6, 7, the detection of a 700 kDa subcomplex retaining NADH dehydrogenase activity indicates an arrest in the assembly process. Genetic analyses established that amc5 and amc7 are alleles of the same locus while amc1 to 4 and amc6 define distinct complementation groups. The locus defined by the amc5 and amc7 alleles corresponds to the NUOB10 gene, encoding PDSW, a subunit of the membrane arm of Complex I. This is the first report of a forward genetic screen yielding the isolation of Complex I mutants. This work illustrates the potential of using Chlamydomonas as a genetically-tractable organism to decipher Complex I manufacture. [less ▲]

Forward-Backward Method with Nonquadratic Kernel for finding a Zero of a Sum of two Maximal Monotone Operators

E-print/Working paper (2001)

An extension of the (nonexact-perturbed) forward-backward method for finding a zero of a sum of two maximal monotone operators is proposed, using a nonlinear metric, tied to Bregman functions. Results of ... [more ▼]

An extension of the (nonexact-perturbed) forward-backward method for finding a zero of a sum of two maximal monotone operators is proposed, using a nonlinear metric, tied to Bregman functions. Results of weak and strong convergence for a sequence generated by such a method are established, under similar assumptions to those appearing in the context of the proximal point algorithm. [less ▲]

Fos Induction in the Japanese Quail Brain after Expression of Appetitive and Consummatory Aspects of Male Sexual Behavior

in Brain Research Bulletin (2000), 52(4), 249-62

We investigated the expression of Fos, the protein product of the immediate early gene c-fos in the brain of male Japanese quail after they engaged in either appetitive or consummatory sexual behavior (i ... [more ▼]

We investigated the expression of Fos, the protein product of the immediate early gene c-fos in the brain of male Japanese quail after they engaged in either appetitive or consummatory sexual behavior (i. e., copulation). For 1 h, castrated males treated with testosterone were either allowed to copulate with a female or to exhibit a learned social proximity response indicative of appetitive sexual behavior. Control birds were either left in their home cage or placed in the experimental chamber but did not exhibit the appetitive sexual behavior because they had never learned it. Fos expression was studied with an immunocytochemical procedure in two sets of adjacent sections through the entire forebrain. These sections were immunolabelled with 2 different antibodies raised against a synthetic fragment corresponding to the 21 carboxy-terminal residues of the chicken Fos sequence. Contrary to the results of a previous study in which gonadally intact birds were used, Fos induction was observed neither in the medial preoptic nucleus nor in the nucleus intercollicularis in birds that had interacted for 1 h with a female. This may be related to a lower frequency of copulation in the testosterone-implanted birds than in intact birds, or to differences in the time the brains were collected after the birds engaged in sexual behavior between the two studies (60 min in this study, 120 min in the previous study). The performance of copulation and/or appetitive sexual behavior increased the number of Fos-immunoreactive cells in the ventral hyperstriatum, medial archistriatum, and nucleus striae terminalis. These increases were observed using both antibodies, although each antibody produced minor differences in the number of Fos-immunoreactive cells observed. Using one of the antibodies, but not the other, increases in Fos immunoreactivity were also observed in the nucleus accumbens and hyperstriatum after either copulation or appetitive sexual behavior. These differences illustrate how minor technical variations in the Fos immunocytochemical procedure influence the results obtained. These differences also show that Fos induction in a number of brain regions is observed after performance of consummatory (copulation) as well as appetitive (looking at the female) sexual behavior. This induction is, therefore, not related solely to the control of copulatory acts but, presumably, also to the processing in a variety of telencephalic association areas of stimuli originating from the female. The observation that increased Fos immunoreactivity is present in birds that had learned the response indicative of appetitive sexual behavior, and not in those that had not learned the behavior, further indicates that it is not simply the sight of the female that results in this Fos induction, but the analysis of the relevant stimuli in a sexually explicit context. Conditioned neural activity resulting from a learned association between the stimulus female and the performance of copulatory behavior may also explain some aspects of the brain activation observed in birds viewing, but not allowed to interact with, the female. [less ▲]

Fosse commune

Book published by Dricot (2005)

Fossil cyanobacterial DNA from sediment cores at Beak Island (Antarctic Peninsula): challenges for a molecular approach

in Decleir, Hugo; De Broyer, Claude; Dehairs, Frank (Eds.) et al CONTACTFORUM Belgian IPY symposium. The contribution of Belgian Research to the achievements of the International Polar Year 2007-2009 (2010)

Two sediment cores taken from lakes BK1 and BK2 in Beak Island (Trinity Peninsula, Antarctic Peninsula) were analysed. The cores were divided in two sections (lacustrine and marine). Changes in ... [more ▼]

Two sediment cores taken from lakes BK1 and BK2 in Beak Island (Trinity Peninsula, Antarctic Peninsula) were analysed. The cores were divided in two sections (lacustrine and marine). Changes in cyanobacterial diversity occurring within the lacustrine section, when the lake was isolated from the sea, were studied. [less ▲]

The fossil plants from the Lower Devonian of Marchin (northern margin of Dinant Synclinorium, Belgium). IV. Odonax borealis gen. et spec. nov.

in Review of Palaeobotany and Palynology (1996), 93

Fossile dépendance

Article for general public (2010)

Décembre 2009, tous les projecteurs sont braqués sur Copenhague. Les Etats du monde y discutent de l’avenir climatique de la planète. En dépit de progrès limités, les plus gros pollueurs de la planète ... [more ▼]

Décembre 2009, tous les projecteurs sont braqués sur Copenhague. Les Etats du monde y discutent de l’avenir climatique de la planète. En dépit de progrès limités, les plus gros pollueurs de la planète (ils représentent au total 80% des émissions) se sont accordés sur la nécessité d’agir pour limiter le réchauffement global à maximum 2°C au-dessus de la température pré-industrielle. [...] [less ▲]

Fotoelektronen Spectroscopie: een nieuwe analyse techniek.

in Chemisch Weekblad (1973), 69(28/29),

Beside the IR-, Raman- and UV-spectroscopies the photoelectron spectroscopy becomes an important technique for the qualitative and quantitative analysis of unknown samples. Important informations related ... [more ▼]

Beside the IR-, Raman- and UV-spectroscopies the photoelectron spectroscopy becomes an important technique for the qualitative and quantitative analysis of unknown samples. Important informations related to the electronic and molecular structure can be obtained by this technique. [less ▲]

Fotogrammi per una "consegna del testimone" : Da Guy Tosi a Ivanos Ciani e alla giovane critica

in Cappellini, Milva Maria; Zollino, Antonio (Eds.) D'Annunzio e dintorni : Studi per Ivanos Ciani (2006)

Foucault lecteur de Husserl : articuler une rencontre

in Bulletin d'Analyse Phénoménologique (2008), 4(3), 202-238

Cet article trace une voie de recherche au sein de l’histoire de la philosophie continentale : il entend revenir sur le partage théorie/pratique à partir d’une confrontation entre l’œuvre de Foucault et ... [more ▼]

Cet article trace une voie de recherche au sein de l’histoire de la philosophie continentale : il entend revenir sur le partage théorie/pratique à partir d’une confrontation entre l’œuvre de Foucault et un ensemble de textes tardifs de Husserl. Dans ce dessein, il place l’accent sur la dimension « ascétique », puis pratique, de la phénoménologie husserlienne (à travers les notions de conversion, d’(auto)méditation, de vie philosophique, enfin de critique historique de nous-mêmes) de façon à nuancer l’image convenue d’une pensée husserlienne strictement intellectualiste. En effet, bien qu’elle culmine dans la réactivation d’une attitude théorétique originaire, il reste : que cette attitude est elle-même fondée par une pratique de soi, dans la pensée ; qu’elle se prolonge en « une nouvelle espèce de pratique », historique, où le sens de l’humanité est pris en charge. Il montre en conclusion qu’au regard d’une ontologie critique de nous-mêmes, ces auteurs couvrent deux régions différentes et contraires, comme en témoigne le rapport divergent qu’ils entretiennent à la question de l’origine, à celle du sujet, enfin au concept d’expérience. [less ▲]