Space Infrared Telescope for Cosmology and Astrophysics (SPICA), the cryogenic infrared space telescope recently pre-selected for a ‘Phase A’ concept study as one of the three remaining candidates for European Space Agency (ESA's) fifth medium class (M5) mission, is foreseen to include a far-infrared polarimetric imager [SPICA-POL, now called B-fields with BOlometers and Polarizers (B-BOP)], which would offer a unique opportunity to resolve major issues in our understanding of the nearby, cold magnetised Universe. This paper presents an overview of the main science drivers for B-BOP, including high dynamic range polarimetric imaging of the cold interstellar medium (ISM) in both our Milky Way and nearby galaxies. Thanks to a cooled telescope, B-BOP will deliver wide-field 100–350 $\mu$m images of linearly polarised dust emission in Stokes Q and U with a resolution, signal-to-noise ratio, and both intensity and spatial dynamic ranges comparable to those achieved by Herschel images of the cold ISM in total intensity (Stokes I). The B-BOP 200 $\mu$m images will also have a factor $\sim $30 higher resolution than Planck polarisation data. This will make B-BOP a unique tool for characterising the statistical properties of the magnetised ISM and probing the role of magnetic fields in the formation and evolution of the interstellar web of dusty molecular filaments giving birth to most stars in our Galaxy. B-BOP will also be a powerful instrument for studying the magnetism of nearby galaxies and testing Galactic dynamo models, constraining the physics of dust grain alignment, informing the problem of the interaction of cosmic rays with molecular clouds, tracing magnetic fields in the inner layers of protoplanetary disks, and monitoring accretion bursts in embedded protostars.

Theoretical and observational work show that jets from AGN can trigger star formation. However, in the Milky Way the first -and so far- only clear case of relativistic jets inducing star formation has been found in the surroundings of the microquasar GRS 1915+105. Here we summarize the multiwavelength observations of two compact star formation IRAS sources axisymmetrically located and aligned with the position angle of the sub-arcsec relativistic jets from the stellar black hole binary GRS 1915+105 (Mirabel & Rodríguez 1994). The observations of these two star forming regions at centimeter (Mirabel & Rodríguez 1998), millimeter and infrared (Chaty et al. 2001) wavelengths had suggested -despite the large uncertainties in the distances a decade ago- that the jets from GRS 1915+105 are triggering along the radio jet axis the formation of massive stars in a radio lobe of bow shock structure. Recently, Reid et al. (2014) found that the jet source and the IRAS sources are at the same distance, enhancing the evidence for the physical association between the jets from GRS 1915+105 and star formation in the IRAS sources. We conclude that as jets from AGN, jets from microquasars can trigger the formation of massive stars, but at distances of a few tens of parsecs. Although star formation induced by microquasar jets may not be statistically significant in the Milky Way, jets from stellar black holes may have been important to trigger star formation during the re-ionization epoch of the universe (Mirabel et al. 2011). Because of the relative proximity of GRS 1915+105 and the associated star forming regions, they may serve as a nearby laboratory to gain insight into the physics of jet-trigger star formation elsewhere in the universe.

Euclid is the next ESA mission devoted to cosmology. It aims at observing most of the extragalactic sky, studying both gravitational lensing and clustering over ~15,000 square degrees. The mission is expected to be launched in year 2020 and to last six years. The sheer amount of data of different kinds, the variety of (un)known systematic effects and the complexity of measures require efforts both in sophisticated simulations and techniques of data analysis. We review the mission main characteristics, some aspects of the the survey and highlight some of the areas of interest to this meeting.

Next year the second generation instrument SPHERE will begin science operations at the Very Large Telecope (ESO). This instrument will be dedicated to the search for exoplanets through the direct imaging techniques, with the new generation extreme adaptive optics. In this poster, we present the performances of one of the focal instruments, the Infra-Red Dual-beam Imaging and Spectroscopy (IRDIS). All the results have been obtained with tests in laboratory, simulating the observing conditions in Paranal. We tested several configurations using the sub-system Integral Field Spectrograph (IFS) in parallel and simulating long coronographic exposures on a star, calibrating instrumental ghosts, checking the performance of the adaptive optics system and reducing data with the consortium pipeline. The contrast one can reach with IRDIS is of the order of 10−6 at 0.5 arcsec separation from the central star.

The role of heterotrophic biofilm of water–sediment interface in detoxification processes was tested in abiotic and biotic conditions under laboratory conditions. Three toxicants, a herbicide (Diuron), a fungicide (Dimethomorph) and an insecticide (Chlorpyrifos-ethyl) have been tested in water percolating into columns reproducing hyporheic sediment. The detoxification processes were tested by comparing the water quality after 18 days of percolation with and without heterotrophic biofilm. Tested concentrations were 30 μg.L−1 of Diuron diluted in 0.1% dimethyl sulfoxide (DMSO), 2 μg.L−1 of Dimethomorph and 0.1 μg.L−1 of Chlorpyrifos-ethyl. To characterise the detoxification efficiency of the system, we performed  genotoxicity bioassays in amphibian larvae and rotifers and measured the respiration and denitrification of sediments. Although the presence of biofilm increased the production of N-(3,4 dichlorophenyl)-N-(methyl)-urea, a metabolite of diuron, the toxicity did not decrease irrespective of the bioassay. In the presence of biofilm, Dimethomorph concentrations decreased compared with abiotic conditions, from 2 μg.L−1 to 0.4 μg.L−1 after 18 days of percolation. For both Dimethomorph and Chlorpyrifos-ethyl additions, assessment of detoxification level by the biofilm depended on the test used: detoxification effect was found with amphibian larvae bioassay and no detoxification was observed with the rotifer test. Heterotrophic biofilm exerts a major influence in the biochemical transformation of contaminants such as pesticides, suggesting that the interface between running water and sediment plays a role in self-purification of stream reaches.

Fifty years after the hyporheic zone was first defined (Orghidan, 1959), there are still gaps in the knowledge regarding the role of biodiversity in hyporheic processes. First, some methodological questions remained unanswered regarding the interactions between biodiversity and physical processes, both for the study of habitat characteristics and interactions at different scales. Furthermore, many questions remain to be addressed to help inform our understanding of invertebrate community dynamics, especially regarding the trophic niches of organisms, the functional groups present within sediment, and their temporal changes. Understanding microbial community dynamics would require investigations about their relationship with the physical characteristics of the sediment, their diversity, their relationship with metabolic pathways, their interactions with invertebrates, and their response to environmental stress. Another fundamental research question is that of the importance of the hyporheic zone in the global metabolism of the river, which must be explored in relation to organic matter recycling, the effects of disturbances, and the degradation of contaminants. Finally, the application of this knowledge requires the development of methods for the estimation of hydrological exchanges, especially for the management of sediment clogging, the optimization of self-purification, and the integration of climate change in environmental policies. The development of descriptors of hyporheic zone health and of new metrology is also crucial to include specific targets in water policies for the long-term management of the system and a clear evaluation of restoration strategies.

The Herschel Dwarf Galaxy Survey investigates the interplay of star formation activity and the the metal-poor gas and dust of local universe dwarf galaxies using FIR and submillimetre imaging spectroscopic and photometric observations in the 50 to 550 μm window of the Herschel Space Observatory. The dust spectral-energy distributions are well constrained with the new Herschel and MIR Spitzer data. A submillimetre excess is often found in low metallicity galaxies, which, if tracing very cold dust, would highlight large dust masses not easily reconciled in some cases, given the low metallicities and expected gas-to-dust mass ratios. The galaxies are also mapped in the FIR fine-structure lines (63 and 145 μm OI, 158 μm CII, 122 and 205 μm NII, 88 μm OIII) probing the low density ionised gas, the HII regions and photodissociation regions. While still early in the mission we can already see, along with earlier studies, that line ratios in the metal-poor ISM differ remarkably from those in the metal-rich starburst environments. In dwarf galaxies, L[CII]/L(CO) (≥104) is at least an order of magnitude greater than in the most metal-rich starburst galaxies. The 88 μm [OIII] line usually dominates the FIR line emission over galaxy-wide scales, not the 158 μm [CII] line which is the dominant FIR cooling line in metal-rich galaxies. All of the FIR lines together can contribute 1% to 2% of the LTIR. The Herschel Dwarf Galaxy survey will provide statistical information on the nature of the dust and gas in low metallicity galaxies and place constraints on chemical evolution models of galaxies.

We characterize PAH populations in 22 metal-poor blue compact dwarf galaxies (BCDs), 16 of which have an oxygen abundance 12+log(O/H) ≲ 8. This is the largest sample ever studied at such low metallicities. The relative PAH intensities of the 6.2, 7.7, 8.6 and 11.3 μm features in these BCDs suggest a deficit of small PAH carriers, or alternatively, an excess of large ones at these low abundances.

The Herschel Dwarf Galaxy Survey investigates the metal enrichment of the dust and gas in galaxies through observations of the local universe dwarf galaxies via the new far-infrared (FIR) and submillimetre imaging spectroscopic and photometric observations from the recently launched Herschel Space Observatory. The dust spectral energy distributions can now be constrained out to submm wavelengths and often show a submm excess in the low metallicity galaxies, which, if tracing very cold dust, could highlight large dust masses, sometimes not easily reconciled with their low-metallicity and observed gas mass. Additionally, Herschel observations of the FIR fine-structure lines probe the low density ionised gas, the HII regions and photodissociation regions. L[CII]/LCO is remarkably high in dwarf galaxies – typically an order of magnitude larger than more metal-rich starburst galaxies, pointing to a potentially significant reservoir of H2 not traced by CO but shielded in the C+-emitting envelopes. Thus a more accurate estimate of the molecular gas mass in low metallicity galaxies will be via the (CO + [CII]) to H2 conversion factor. The 88 μm [OIII] line is the brightest of all FIR lines in low-metallicity galaxies, sometimes 1.5 to 2 time brighter than the 158 μm [CII] line which is usually the dominate FIR coolant in normal spiral and starburst galaxies. The 88 μm [OIII] line may become the workhorse diagnostic for the high-redshift low-metallicity galaxies which will be targets for future submm observatories, such as ALMA. Further observations from The Herschel Dwarf Galaxy survey will provide a more complete picture of the nature of the dust and gas in low metallicity galaxies and thus a more comprehensive view of the chemical evolution of galaxies.

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

The European Space Agency is building a space telescope to observe the Universe in the Far-IR and sub-millimeter regime of the electromagnetic spectrum. The scientific payload is composed of three instruments. One of them, PACS, is equipped with a novel type of bolometer arrays developed by CEA in the late 90's. We briefly present the PACS Photometer and the architecture of CEA filled bolometer arrays. We accessed the physics of the detectors and thoroughly measured their performances by developing a pragmatic calibration procedure. The Photometer is now calibrated and integrated on the focal plane of the observatory. The launch is scheduled for April 2009. Meanwhile, CEA is working on adapting PACS bolometers to longer wavelength for wide-field ground-based telescopes, and for the future cold-telescope space mission SPICA.

Epidemiological data from bank voles, Myodes glareolus, naturally infected by the hantavirus Puumala (PUUV) were collected by a capture–mark–recapture protocol from 2000 to 2002 in the French department of Ardennes. Four monitored trapping sites were established in two forests located in two cantons (Flize and Monthermé). We captured 912 bank voles corresponding to 557 different individuals during 8820 trapping nights for an overall trapping success of 10·34%. The average PUUV seroprevalence was 22·4%. Characteristics of the system reported in North European countries are confirmed in France. PUUV seroprevalence and abundance of rodents appeared weakly linked. Adult voles were more frequently antibody-positive, but no difference between sexes was established. Anti-PUUV seropositive voles were captured and high seroprevalence was observed from both forests, without human infection reported in Flize canton during the study. One site among the four exhibited peculiar infection dynamics, where vole weight and infection risk were negatively correlated.

The paper proposes a model explaining the spatial variation in incidence of nephropathia epidemica in Europe. We take into account the rodent dynamic features and the replicative dynamics of the virus in animals, high in the acute phase of newly infected animals and low in the subsequent chronic phase. The model revealed that only vole populations with multi-annual fluctuations allow for simultaneously high numbers of infected rodents and high proportions of those rodents in the acute excretion phase during the culminating phase of population build-up. This leads to a brief peak in exceptionally high concentrations of virus in the environment, and thereby, to human exposure. Such a mechanism suggests that a slight ecological disturbance in animal–parasite systems could result in the emergence of human diseases. Thus, the potential risk for public health due to several zoonotic diseases may be greater than previously believed, based solely on the distribution of human cases.

LiFePO4-based powders prepared through various synthesis conditions are presented. Depending on whether the precursors contain carbon or not, LiFePO4-based composites obtained contain significant amounts of carbon as well. We did not succeed in doping LiFePO4 with Nb and produced, instead, crystalline β-NbOPO4 and/or an amorphous (Nb, Fe, C, O, P) matrix around LiFePO4 particles. The total electrical conductivity is of ∼10−9 S.cm−1 at 25°C with an activation energy of ca. 0.65 eV for pure LiFePO4 and LiFePO4/β-NbOPO4 composite. C-containing LiFePO4 samples, including those that had been tentatively doped with Nb, are much more conductive (up to 1.6.10−1 S.cm−1) with an activation energy ΔE ∼ 0.08 eV.

Experimental results are reported on various guided optic configurations that combine silicon-based photonic crystals (PC) and Ge/Si quantum island emitters. The feasibility of low-refractive-index-contrast PC waveguides by inductively-coupled-plasma (ICP) etching of buried SiGe/Si waveguides is briefly recalled from a previous work. The main body of the paper is focused on experiments that were carried out on the high-refractive-index-contrast silicon-on-insulator (SOI) system. Self-assembled Ge/Si quantum island layers were deposited on a SOI substrate that was further processed to get two-dimensional PC microcavities and waveguides. The room temperature 1.3–1.55 μm emission from Ge/Si islands is shown to be significantly enhanced in PC microcavities, the strongest enhancement being obtained with the smallest (micropillar-like) cavities surrounded by wide pores. In this latter case, the room-temperature photoluminescence amplitude is more than two-orders of magnitude larger than that of Ge/Si islands grown in unprocessed samples. A superlinear (laser-like) dependence with the optical pumping is observed in the same time. This behavior and other experimental trends would incriminate both a high carrier concentration of the photo-created electron-hole plasma and a good vertical coupling efficiency of the micro-structured silicon. A first attempt to characterize linear PC waveguides is also reported using the wideband luminescence of Ge/Si islands embedded in the guides.

In a randomized, double-blind, placebo-controlled trial we evaluated the effect of dietary chocolates enriched with a wood-based phytosterol–phytostanol mixture, containing 18% (w/w) sitostanol, compared with placebo dietary chocolates in seventy subjects with primary hypercholesterolaemia (total cholesterol levels below 8 mmol/l). For 4 weeks, participants consumed three servings of the phytosterol-enriched chocolate/d that provided 1·8 g unesterified phytosterols/d or a placebo chocolate in conjunction with a low-fat, low-cholesterol diet. Plasma total and LDL-cholesterol levels were statistically significantly reduced by 6·4% (−0·44 mmol/l) and 10·3% (−0·49 mmol/l), respectively, after 4 weeks of phytosterol-enriched-chocolate treatment. Plasma HDL-cholesterol and triacylglycerol levels were not affected. Consumption of phytosterol-enriched chocolates significantly increased plasma lathosterol concentration (+20·7%), reflecting an increased endogenous cholesterol synthesis in response to phytosterol-induced decreased intestinal cholesterol absorption. Furthermore, the chocolates enriched with phytosterols significantly increased both plasma sitosterol (+95·8%) and campesterol (+64·1%) levels, compared with the placebo chocolate group. However, the absolute values of plasma sitosterol and campesterol remained within the normal range, that is, below 10 mg/l. The chocolates with phytosterols were palatable and induced no clinical or biochemical side effects. These findings indicate that dietary chocolate enriched with tall oil-derived phytosterols (1·8 g/d) is effective in lowering blood total and LDL-cholesterol levels in subjects with mild hypercholesterolaemia and thus may be helpful in reducing the risk of CHD in these individuals.

We present a new method based on mid-IR (5 — 16 µm) emission for classifying the origin of the mid-IR activity in galaxies. Our method was devefoped using a set of 33 ISOCAM spectra of extragalactic sources which exhibit diverse mid-IR spectral features. Detailed analysis of our sample enables us to identify the general properties of mid-IR emission from active galactic nuclei (AGNs), starbursts, and quiescent star forming regions. The benefits of this mid-IR classification for identifying obscured or faint AGNs and for estimating the star formation intensity in star-forming regions are investigated.

We have investigated the emission properties of InAs/GaAs self-assembled quantum dots in the mid-infrared. The emission relies on the intraband transitions in the valence band of the quantum dots. We first show that third-harmonic generation can be observed. The frequency tripling efficiency is enhanced by the resonances between the pump excitation and the quantum dot intraband transitions. A giant third-order nonlinear susceptibility is measured for one dot plane. The narrow spectral dependence of the nonlinear susceptibility is well explained by simulations which account for the three-dimensional confinement potential. We secondly show that the mid-infrared spontaneous emission between hole confined states can be observed under an interband optical pumping. The spontaneous emission involves transitions between either the ground and excited states or between excited states. These measurements demonstrate the potentiality of self-assembled quantum dots for mid-infrared emission.

We performed systematic infrared observations of the intermediate-age Magellanic Clouds clusters NGC 419, NGC 1783 and NGC 1978. Mid-infrared stars discovered in NGC 419 and NGC 1978 are very red and must be undergoing intense mass loss (comparable to superwinds). They are probably carbon stars but do not seem to show any FIR excesses. Three optically visible carbon stars as well as (at least) 2 near-infrared carbon stars observed with ISOPHOT show 60 μm excesses which may indicate mass loss in the past. It seems that the MIR stars are fainter than the AGB tip luminosity and that their Mbols are close to those of the transition luminosity from M type to C stars. Therefore, these MIR stars may not be in the final stage of the AGB phase. This may suggest that AGB stars lose mass heavily at some other time, possibly during the transition from M type to C stars.