Darwin--a mission to detect and search for life on extrasolar planets.

The discovery of extrasolar planets is one of the greatest achievements of modern astronomy. The detection of planets that vary widely in mass demonstrates that extrasolar planets of low mass exist. In this paper, we describe a mission, called Darwin, whose primary goal is the search for, and characterization of, terrestrial extrasolar planets and the search for life. Accomplishing the mission objectives will require collaborative science across disciplines, including astrophysics, planetary sciences, chemistry, and microbiology. Darwin is designed to detect rocky planets similar to Earth and perform spectroscopic analysis at mid-infrared wavelengths (6-20 mum), where an advantageous contrast ratio between star and planet occurs. The baseline mission is projected to last 5 years and consists of approximately 200 individual target stars. Among these, 25-50 planetary systems can be studied spectroscopically, which will include the search for gases such as CO(2), H(2)O, CH(4), and O(3). Many of the key technologies required for the construction of Darwin have already been demonstrated, and the remainder are estimated to be mature in the near future. Darwin is a mission that will ignite intense interest in both the research community and the wider public.

Anaerobic digestion of residual municipal solid waste using biological-mechanical pre-treatment: the plant of Varennes Jarcy.

Residual municipal solid waste can be treated by anaerobic digestion after a sorting process in order to remove the unwanted materials. After a mechanical sorting the quality of the final compost can hardly cope with requirements for agriculture use. In this way, a more efficient sorting process using a specific equipment that provides a combined biological and mechanical effect, has been implemented on the plant of Varennes Jarcy prior to anaerobic digestion. This paper presents the main results obtained on this plant. The reduction of biodegradable organics in particle lower than 10 mm allows a very efficient separation by screening. An additional ballistic sorting removes the remaining glass. The composition of the resulting sorted waste was close to a source-sorted organic fraction. The sorted waste exhibit methane yields comparable with raw biodegradable organics, showing that the pre-treatment had little impact on anaerobic digestion performance.

Comparative phylogeography of two coastal polychaete tubeworms in the Northeast Atlantic supports shared history and vicariant events.

The historic processes which have led to the present-day patterns of genetic structure in the marine coastal fauna of the Northeast Atlantic are still poorly understood. While tectonic uplifts and changes in sea level may have caused large-scale vicariance, warmer conditions during glacial maxima may have allowed pockets of diversity to persist to a much wider extent than in the Northwestern Atlantic. The large-scale geographic distribution of deeply divergent lineages of the coastal polychaete tubeworms Pectinaria koreni (two clades) and Owenia fusiformis (three clades) were compared using a fragment of the mitochondrial cytochrome oxidase I gene (mtCOI). All lineages were present along the biogeographic transition zone on the north coast of Brittany (France) and we found evidence pointing towards congruence in the timing of cladogenic events between Pectinaria sp. (P. auricoma/P. belgica and P. koreni) and Owenia sp., suggesting a shared history of vicariant events. More conserved 16SrRNA sequences obtained from four species of Pectinariidae together with mtCOI sequences of P. koreni seem consistent with an initial establishment of pectinariids in the north, and a southward colonization of the Northeast Atlantic. Phylogeographic patterns in O. fusiformis were also consistent with a north/south pattern of lineage splitting and congruent levels of divergence were detected between lineages of both species. We observed signatures of both persistence in small northern glacial refugia, and of northwards range expansion from regions situated closer to the Mediterranean. However, whether the recolonization of the Northeast Atlantic by both species actually reflects separate interglacial periods is unclear with regards to the lack of molecular clock calibration in coastal polychaete species.

Sharp genetic break between Atlantic and English Channel populations of the polychaete Pectinaria koreni, along the North coast of France.

This study uses enzymatic and mitochondrial genes to infer the relative importance of historical processes and contemporary hydrodynamic features on the observed patterns of genetic structure in subdivided populations of Pectinaria koreni (Polychaeta: Pectinariidae) along the coasts of Brittany and the English Channel. Nucleotide sequence variation of a 603-bp fragment of the mtDNA cytochrome oxidase subunit I gene revealed a surprisingly deep phylogeographic break of about 16% divergence separating the Brittany and Channel populations, which coincides with a biogeographic boundary along the western coast of Brittany. Deep sequence divergence with fixed haplotype differences and the inversion of allele frequencies at two enzyme loci suggests the occurrence of potential cryptic or sibling species of P. koreni. The two clades showed opposite features. Channel populations exhibited bimodal match-mismatch curves due to two highly divergent haplotypes occurring at high frequencies and no overall heterozygote deficiencies at enzyme loci, suggesting respectively, a historic secondary contact between two differentiated populations followed by contemporary panmixia. On the contrary, Brittany populations displayed unimodal curves with low nucleotide diversity and highly significant heterozygote deficiencies, probably reminiscent of a recent population expansion and recolonisation of Brittany with contemporary admixture of divergent populations.

[Study of dissociative disorders and depersonalization in a sample of young adult French population]. / Etude des troubles dissociatifs et de la dépersonnalisation au sein d'un échantillon de la population française adulte jeune.

UNLABELLED: Questioned by several researches about dissociative disorders, the authors study differences established on the nosographic register, through a quantitative study and a psychodynamic argumentation in a sample of french population. From the utilisation of the Dissociative Experiences Scale (DES) created by Bernstein E and Putnam FW (1986), which is an excellent screening tool for dissociative disorders and constructed on DSM II diagnostic criterions, the authors will show the interest of a psychodynamic analysis of dissociative disorders, in the face of the diagnostic difficulty in relation to several approaches of this concept. This difficulty is studied giving the background to dissociative disorders and depersonalization. Ionescu (1999) shows that between 1890 and 1910 dissociation represents one of major themes of psychology, psychopathology and psychiatry. Then, this interest about dissociation decreases and will be almost non-existent in the middle of the twentieth century. The interest for dissociative disorder will grow in the eighties with north-american studies about multiple personality disorders. Until 1980, dissociative disorders exist in DSM II as a list of symptoms included into hysterical neurosis, among the conversive disorders. In 1980, the publication of DSM III replaces the notion of hysteria with the notion of dissociative disorder. In this way, we can see on the one hand somatoform disorders quarterly corresponding to the ancient version of conversive hysteria, and on the other hand dissociative disorders characterized by a perturbation of consciousness, memory, identity or perception of environment. In 1994, The DSM IV delete the notion of hysteria and neurosis and keeps only the notion of dissociative disorders. They include now the five following categories: dissociative amnesia, dissociative fugue, depersonalization disorder, dissociative identity disorder, dissociative disorder not otherwise specified (including derealization). Depersonalization disorders consist of "persistent or recurrent episodes of depersonalization characterized by a feeling of detachment or estrangement from one's self. The individual may feel like an automation or like he or she is living in a dream or movie" (DSM IV). Depersonalization disorder cannot be diagnosed if it is part of schizophrenia, panic disorder, acute stress disorder or dissociative identity disorder. Various depressive disorders, hypocondriasis or obsessive-compulsive disorders can accompany depersonalization disorder. The first purpose of this study will search the frequency of dissociative disorders and depersonalization in a sample of normal population. Further, the inclusion of depersonalization amongst dissociative disorders seems not so evident: depersonalization belongs to self-consciousness disorder in french psychiatry. This fact seems more logical insofar as dissociative disorders have all together a memory and consciousness perturbation, and this perturbation is missing from depersonalization's feeling. The second purpose will be to clarify and specify the particularity of depersonalization among dissociative diorders, from the psychopathological point of view. METHODOLOGY: The sample (n = 248) is made up of french young adults aged 17 to 30 (mean age = 20, SD = 15 and 24% is male population). Subjects were streamming from universities. The screening tool which was used is the Dissociative Experiences Scale, a 28-item patient questionnaire regarding various dissociative symptoms. The subject is asked to indicate the percentage of time, to the nearest 5%, that particular symptom is experienced. The score is made by adding the various percentages and finding a mean that is expressed in numbers from 0 to 100. Normal scores are in the range of 5 to 15 in american adults. RESULTS: The utilization of principal component analysis (PCA) with varimax rotation is justified by the will to compare this study with American's studies. The mean score obtained is 17.44%, and 13.3% of the scores exceed a psychiatric threshold at 30%. The descriptive analysis shows that the component 1 (PCA without varimax rotation) represents 33.02% of total explained variance. This result demonstrates that the structure of the DES is based on one concept, the same as the american population, it is the concept of dissociation. The Principal Component Analysis with varimax rotation of the DES ratings yielded a tree-factor solution: imaginative absorption (F1), depersonalization-derealization (F2) and dissociative amnesia (F3). Mean score for each factor is respectively: F1 = 21.56%, F2 = 13.95%, F3 = 11.04%. DES reliability was studied through computation of Cronbach's coefficient (0.92). The PCA with varimax rotation brings to the fore a full dissociative disorder without any trouble of memory and consciousness. This fact questions again once more the link between hysteria and dissociative disorders. There is here a clinical distinction between depersonalization-derealization and other dissociative disorders. Indeed, the absence of significant alteration of memory and conscience is specific of depersonalization and derealization in this study. CONCLUSION: Finally, this study concurs with DSM IV dissociative criterions. At last, one factor of PCA is composed by the association of depersonalization and derealization, in contradiction with DSM IV definition. This result shows that, into the french population, we cannot divide the two concepts.

Photometric observations of a polychromatic laser guide star.

We report the photometric observation of a polychromatic laser guide star (PLGS) using the AVLIS laser at the Lawrence Livermore National Laboratory (LLNL). The process aims at providing a measurement of the tilt of the incoming wave front at a telescope induced by atmospheric turbulence. It relies on the two-photon coherent excitation of the 4D5/2 energy level of sodium atoms in the mesosphere. We used two laser beams at 589 and 569 nm, with a maximum total average output power of approximately 350 W. For the purpose of photometric calibration, a natural star was observed simultaneously through the same instrument as the PLGS at the focus of the LLNL 50-cm telescope. Photometric measurements of the 330-nm return flux confirm our previous theoretical studies that the PLGS process should allow us at a later stage to correct for the tilt at wavelengths as short as approximately 1 microm at good astronomical sites. They show also that, at saturation of two-photon coherent absorption in the mesosphere, the backscattered flux increases by a factor of approximately 2 when the pulse repetition rate decreases by a factor of 3 at constant average power. This unexpected behavior is briefly discussed.