From 2014 to 2020, we compiled radiocarbon ages from the lower 48 states, creating a database of more than 100,000 archaeological, geological, and paleontological ages that will be freely available to researchers through the Canadian Archaeological Radiocarbon Database. Here, we discuss the process used to compile ages, general characteristics of the database, and lessons learned from this exercise in “big data” compilation.

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.

In recent decades, the invasive Aedes albopictus vector has spread across Europe and is responsible for numerous outbreaks of autochthonous arboviral disease. The aim of this study was to identify epidemiological and sociological risk factors related to individual levels of exposure to Aedes albopictus bites. A multidisciplinary survey was conducted with volunteer blood donors living in areas either colonised or not by Aedes albopictus in mainland France. Individual levels of exposure were evaluated by measuring the IgG level specific to Aedes albopictus saliva. The most striking risk factors concerned the localisation and characteristics of the dwelling. Individuals living in areas colonised prior to 2009 or recently colonised (between 2010 and 2012) had higher anti-salivary gland extract IgG levels compared with those who were living in areas not yet colonised by Ae. albopictus. The type of dwelling did not seem to impact the level of exposure to Aedes bites. People living in apartments had a higher anti-salivary gland extract IgG level than those living in individual houses but the difference was not statistically significant. Interestingly, the presence of air conditioning or window nets was associated with a noticeable reduction in bite intensity.

The mineralogical, geochemical and micromorphological features of an isalteritic clay facies, which originated from weathering of an anorthosite, were compared to those of clay facies derived from the degradation of a bauxite developed from the same rock. The isalteritic clay was formed by the hydrolytic alteration of plagioclase, whereas the degraded clays were formed by decomposition of gibbsite and neoformation of kaolinite. This resilification process resulted from the reintroduction of silica via the oscillation of the phreatic level and/or the decomposition of organic matter on the surface. The degradation process was gradual and yielded two different facies: (a) degraded clays with almost total decomposition of gibbsite, and (b) degraded clays with gibbsite nodules. Morphologically, the isalteritic clays differ from the degraded clays because they contain larger hexagonal and pseudo-hexagonal crystals. The degraded clays have more irregular crystal shapes, ranging from laths to anhedral shapes.

PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5-m optical/infrared telescope to be located at Dome C on the Antarctic plateau. Conditions at Dome C are known to be exceptional for astronomy. The seeing (above ∼30 m height), coherence time, and isoplanatic angle are all twice as good as at typical mid-latitude sites, while the water-vapour column, and the atmosphere and telescope thermal emission are all an order of magnitude better. These conditions enable a unique scientific capability for PILOT, which is addressed in this series of papers. The current paper presents an overview of the optical and instrumentation suite for PILOT and its expected performance, a summary of the key science goals and observational approach for the facility, a discussion of the synergies between the science goals for PILOT and other telescopes, and a discussion of the future of Antarctic astronomy. Paper II and Paper III present details of the science projects divided, respectively, between the distant Universe (i.e. studies of first light, and the assembly and evolution of structure) and the nearby Universe (i.e. studies of Local Group galaxies, the Milky Way, and the Solar System).

The near-infrared (NIR) spectral range (2–5 μm) contains a number of interesting features for the study of the interstellar medium. In particular, the aromatic and aliphatic components in carbonaceous dust can be investigated most efficiently with the NIR spectroscopy. We analyze NIR spectra of the diffuse Galactic emission taken with the Infrared Camera onboard AKARI and find that the aliphatic to aromatic emission band ratio decreases toward the ionized gas, which suggests processing of the band carriers in the ionized region.

Within the Herschel key project “The Warm And Dense ISM” (WADI) we systematically observe a number of prominent photon-dominated regions (PDRs) to measure the impact of varying UV fields on the energy balance, the chemical and dynamical structure of heated molecular clouds.

Near infrared observations of reflection nebulae have set the historical ground for the discovery of interstellar PAHs, but since, space observations have focused on their mid-IR features, and data shortward of 5   μm have remained scarce. The Spitzer/IRAC images in the 3.6 and 4.5   μm channels do show that the near-IR emission from small dust particles is ubiquitous across the Galaxy, but provide no spectroscopic information. To investigate the nature of this near-IR dust emission, we have obtained AKARI spectroscopic observations, over the 2.5−5   μm spectral range, for a set of archetype PDRs mapped with the Spitzer spectrometer at mid-IR wavelengths. These AKARI data supplement earlier observations with the SWS ISO spectrometer, in providing the gain in sensitivity needed to observe low excitation sources, and the spatial information required to spatially correlate near-IR spectroscopic signatures with physical conditions and observed changes in mid-IR spectra. This paper presents the first results of the data analysis, in relation to two open questions on interstellar PAHs. (1) Is there an evolutionary link from aliphatic carbon dust to PAHs? (2) What is the origin of the near-IR dust continuum? The AKARI spectra display features longward of the main 3.29   μm PAH feature, and continuum emission. The intensity ratio between the features ascribed to aliphatic CH bonds and the 3.29   μm aromatic band, varies spatially in a way that may be interpreted as evidence for aromatization of the smallest dust particles by photo-processing. The continuum displays a striking step-increase across the 3.29   μm feature. We also present a spectrum of a photodissociation region with a feature at 4.65   μm, which has been speculated to be related to the CD stretch in aliphatic hydrocarbon side-groups on PAHs.

Numerical simulations provide an increasingly detailed picture of the build-up of the stellar mass of galaxies, but they remain schematic in their description of the dissipative processes which regulate star formation. The mechanical energy released by mergers, gas accretion, the formation of bound systems and feedback must be dissipated for star formation to occur and proceed. Spectroscopy of warm H2 observations with the Spitzer Space Telescope and the SINFONI spectro-imager at ESO have unraveled an unexpected facet of the energetics of galaxy and star formation. They show that the dissipation processes involve the formation and dynamical heating of molecular gas. I present the physical understanding of the energetics of the multi-phase, turbulent interstellar medium, which arises from the observations and data modeling.

The effects of parasite infection by the cestode Ligula intestinalis on the reproductive function and endocrine system of wild roach Rutilus rutilus were evaluated. Gonad maturation, plasma vitellogenin, plasma steroid concentrations (i.e. progesterone, 11-keto-testosterone and 17-β-estradiol) and brain aromatase activity were investigated in relation with parasitization. A low prevalence (8%) of ligulosed roach and a moderate impact of parasitization (mean parasitization index of 8·8%) were found in the studied population. Inhibition of gonad maturation generally resulted from infestation but 5% of the ligulosed roach nevertheless reached maturity. Main sex steroid plasma content was depleted in both genders. Male 11-keto-testosterone, female 17-β-estradiol and progesterone plasma concentrations of both genders were, respectively, 27, 5 and 3 times lower in ligulosed fish when compared to their non-infected counterparts. Progesterone levels were negatively correlated with the parasitization index in females. Brain aromatase activity of infected roach was reduced to 50% of that of the non-infected fish. These results demonstrate significant negative effects on the reproductive function of wild roach infected by the tapeworm L. intestinalis collected from a site with low contamination.

The major surface immunodominant antigen (P30) of Toxoplasma gondii was purified by two methods (i) SDS–PAGE and (ii) immunoaffinity chromatography. The secondary elements within this protein were assessed by circular dichroism and spectra obtained were compared to those proposed by Manavalan & Johnson (1983). The results allowed us to determine an all β protein status for this antigen. This experimental result was in agreement with the predicted secondary structures deduced from the P30 primary sequence. Modifications in conformation according to pH and temperature were recorded without any change in immunoactivity. The epitope, which was always recognized by a monoclonal antibody against P30, could be a linear epitope.

The observational constraints on interstellar dust are summarized. A dust model, consisting of a mixture of amorphous silicate, graphite, and PAH material that reproduces the observed interstellar extinction, is described. It is used to calculate the infrared emission expected when such dust is heated by radiation with the spectrum of interstellar starlight with various intensities. By adopting a suitable size distribution for the smallest carbonaceous grains (PAHs), and a distribution of starlight intensities, one can reproduce the observed global emission spectrum of galaxies. This allows the total dust mass, and the PAH abundance, to be estimated for any galaxy with a spectral energy distribution measured by the IRAC and MIPS cameras on Spitzer Space Telescope. For the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample, galaxies with metallicities Z > 0.3 Z๏ tend to have a major fraction of their refractory elements in dust grains, just as in the Milky Way. For lower metallicity galaxies with extended H I envelopes, the overall dust-to-metals ratio remains uncertain. The PAH abundance index qPAH (the fraction of the total dust mass in PAH particles with NC < 103 C atoms) is dependent on metallicity: galaxies with Z <0.3 Z๏ have median qPAH = 1.1%, whereas galaxies with Z > 0.3 Z๏ have median qPAH = 3.5%. The reasons for the pronounced dependence of qPAH on metallicity remain unclear.

This introductory article aims to give a brief overview of our current view of interstellar dust studies with a particular emphasis on the properties of dust at low temperatures and long wavelengths. An understanding of these dust properties will be key in unravelling the wealth of data that will be forthcoming from the imminent, space-based Herschel and Planck missions, and from the ALMA telescopes.

Laboratory measurements aimed at studying the properties of carbonaceous materials and their evolution under simulated space conditions support the idea that interstellar carbon dust evolves through exposure to UV and cosmic rays, gas and heat. After summarizing the principal aspects of the laboratory approach to the problem of cosmic carbon dust, we discuss recent laboratory results showing how carbon grains influence the properties and evolution of ices mantles and the formation of molecular hydrogen.

Good knowledge of the far-infrared and millimeter emission from dust in the interstellar medium is important to get reliable estimates of the dust mass, to trace and understand the evolution of pre-stellar structures, and to accurately subtract the foreground emission in the cosmological background anisotropy measurements. Up to now the modeled dust emission profile in FIR and millimeter wavelength range is deduced from the wings of some mid-infrared fundamental lattice-resonances inside the silicate material, which is known to be the dominant constituent of this dust component. However recent astronomical observations have shown that the dust emission profile could be significantly more complicated than expected. In addition, spectroscopic studies in the laboratory on analogues of amorphous interstellar grains have revealed that additional processes can occur in that spectral range, which are strongly temperature-dependent. We propose a new model for far-infrared and millimeter dust emission which takes into account results from the solid state physics, used to interpret these laboratory data. This model explicitly incorporates the effect of the disorder in the internal structure of the dust grain. We show that this model can give a satisfactory interpretation for the astronomical observations. It opens new perspectives to derive some new dust characteristics from the shape of the dust emission spectrum.

Silicates form a major component of cosmic dust. This paper summarizes the main structural and spectroscopic properties of amorphous and crystalline silicates. Furthermore, it reviews our knowledge of cosmic silicates in the Galaxy. Recent in-situ studies of presolar silicates extracted from primitive meteorites and anhydrous interplanetary dust grains will be discussed.

IR spectroscopy is the premier tool to study the composition of interstellar dust. Broad absorption and emission bands provide direct identification of the solid compounds present in space and allow measurement of accurate abundances. Systematic studies of large samples of sources allow then inferences on the origin and evolution of dust in space. Overall, the observed infrared spectra of interstellar and circumstellar dust reveals an incredibly rich and varied composition. This chapter briefly reviews the principles of infrared spectroscopy. This is then applied to the composition of circumstellar oxides and minerals and interstellar Polycyclic Aromatic Hydrocarbon molecules.

When the most primitive types of meteorite (chondrites) and interplanetary dust particles (IDPs) formed in the solar protoplanetary disk (solar nebula), all of them incorporated at least two types of presolar material: interstellar organic matter and circumstellar grains. The organic matter probably formed in the protosolar molecular cloud. To date, 10 types of circumstellar grain have been found and their isotopic compositions show that they formed around RGB/AGB stars, supernovae and, possibly, novae and WR stars. It has been proposed that interstellar silicates are also present in IDPs, but the evidence for this is less compelling.
The range of isotopic compositions exhibited by the circumstellar grains require a minimum of 35–40 stellar sources, suggesting that they are a fairly representative sample of circumstellar dust production in the Galaxy. In general, the relative abundances of circumstellar grains from different sources are similar to what is expected from astronomical estimates provided that the contribution from supernovae is relatively small. The one exception is graphite grains from AGB stars that are highly depleted.
Collisional erosion, radiation damage and sputtering are all expected to affect grains in the ISM on relatively short timescales. Yet, for reasons that are unclear, examination of the circumstellar grains has found little evidence for any of these processes.
The circumstellar grains also provide information about grain nucleation and growth in stellar winds. For instance, only graphite grains from AGB stars seem to have formed by heterogeneous nucleation. Graphite and SiC grains from AGB stars as large as 10–20 µm have been found in meteorites, probably requiring regions of high gas density rather than the usual assumption of uniformly expanding outflows. However, few graphite and SiC grains have similar C isotopic compositions, suggesting that they tend to form at different stages of AGB evolution.