Qiviut cortisol reflects hypothalamic-pituitary-adrenal axis activity in muskoxen (Ovibos moschatus).

Muskoxen (Ovibos moschatus) are increasingly exposed to a broad diversity of stressors in their rapidly changing Arctic environment. There is an urgent need to develop validated tools to monitor the impact of these stressors on the hypothalamic-pituitary-adrenal (HPA) axis activity of muskoxen to help inform conservation actions. Here, we evaluated whether muskox qiviut (dense wooly undercoat) cortisol accurately reflects changes in HPA axis activity. Two repeated pharmacological challenges, involving weekly administrations of saline (control group) or adrenocorticotropic hormone (ACTH) during five consecutive weeks, were done on captive muskoxen, in winter (no hair growth) and summer (maximum hair growth). Pre-challenge qiviut cortisol levels were significantly higher in the shoulder than in the neck, but neither differed from rump concentrations. Qiviut cortisol levels significantly increased (p < 0.001) in response to the administration of ACTH during the hair growth phase, but not in the absence of growth (p = 0.84). Cortisol levels in the qiviut segment grown during the summer challenge increased significantly over a six-month period in the ACTH-injected muskoxen with a similar trend occurring in the control animals. Finally, cortisol levels in shed qiviut were significantly higher and not correlated to those of fully grown qiviut shaved three months earlier. Our results show that cortisol is deposited in qiviut during its growth and that qiviut cortisol can thus be used as an integrated measure of HPA axis activity over the period of the hair's growth. Differences in qiviut cortisol across body regions, significant differences in qiviut segments over time, and differences between shed qiviut versus unshed qiviut, highlight the importance of consistent design and methodology for sample collection and analyses in order to account for sources of variation when using qiviut cortisol as a biomarker of HPA axis activity in muskoxen.

Far-infrared observations of a massive cluster forming in the Monoceros R2 filament hub⋆.

We present far-infrared observations of Monoceros R2 (a giant molecular cloud at approximately 830 pc distance, containing several sites of active star formation), as observed at 70 µm, 160 µm, 250 µm, 350 µm, and 500 µm by the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) instruments on the Herschel Space Observatory as part of the Herschel imaging survey of OB young stellar objects (HOBYS) Key programme. The Herschel data are complemented by SCUBA-2 data in the submillimetre range, and WISE and Spitzer data in the mid-infrared. In addition, C18O data from the IRAM 30-m Telescope are presented, and used for kinematic information. Sources were extracted from the maps with getsources, and from the fluxes measured, spectral energy distributions were constructed, allowing measurements of source mass and dust temperature. Of 177 Herschel sources robustly detected in the region (a detection with high signal-to-noise and low axis ratio at multiple wavelengths), including protostars and starless cores, 29 are found in a filamentary hub at the centre of the region (a little over 1% of the observed area). These objects are on average smaller, more massive, and more luminous than those in the surrounding regions (which together suggest that they are at a later stage of evolution), a result that cannot be explained entirely by selection effects. These results suggest a picture in which the hub may have begun star formation at a point significantly earlier than the outer regions, possibly forming as a result of feedback from earlier star formation. Furthermore, the hub may be sustaining its star formation by accreting material from the surrounding filaments.

Comet-like mineralogy of olivine crystals in an extrasolar proto-Kuiper belt.

Some planetary systems harbour debris disks containing planetesimals such as asteroids and comets. Collisions between such bodies produce small dust particles, the spectral features of which reveal their composition and, hence, that of their parent bodies. A measurement of the composition of olivine crystals (Mg(2-2x)Fe(2x)SiO(4)) has been done for the protoplanetary disk HD 100546 (refs 3, 4) and for olivine crystals in the warm inner parts of planetary systems. The latter compares well with the iron-rich olivine in asteroids (x ≈ 0.29). In the cold outskirts of the ß Pictoris system, an analogue to the young Solar System, olivine crystals were detected but their composition remained undetermined, leaving unknown how the composition of the bulk of Solar System cometary olivine grains compares with that of extrasolar comets. Here we report the detection of the 69-micrometre-wavelength band of olivine crystals in the spectrum of ß Pictoris. Because the disk is optically thin, we can associate the crystals with an extrasolar proto-Kuiper belt a distance of 15-45 astronomical units from the star (one astronomical unit is the Sun-Earth distance), determine their magnesium-rich composition (x = 0.01 ± 0.001) and show that they make up 3.6 ± 1.0 per cent of the total dust mass. These values are strikingly similar to those for the dust emitted by the most primitive comets in the Solar System, even though ß Pictoris is more massive and more luminous and has a different planetary system architecture.

Frequency noise of free-running 4.6 µm distributed feedback quantum cascade lasers near room temperature.

The frequency noise properties of commercial distributed feedback quantum cascade lasers emitting in the 4.6 µm range and operated in cw mode near room temperature (277 K) are presented. The measured frequency noise power spectral density reveals a flicker noise dropping down to the very low level of <100 Hz(2)/Hz at 10 MHz Fourier frequency and is globally a factor of 100 lower than data recently reported for a similar laser operated at cryogenic temperature. This makes our laser a good candidate for the realization of a mid-IR ultranarrow linewidth reference.

Cerebral amyloid angiopathy-related inflammation: an emerging disease.

Three elderly patients with, respectively: mild cognitive impairment, severe and progressive neurologic involvement, and focal neurologic deficit, were observed. MRI showed multiple areas of white matter edema, at times partially involving the cortex, in the first two patients, and a single area in the third. Treatment with steroids determined the disappearance of the lesions and clinical amelioration. The key to the diagnosis of cerebral amyloid angiopathy-related inflammation (CAA-ri) was the demonstration, with appropriate MRI sequences, of microbleeds consistent with cerebral amyloid angiopathy (CAA). This diagnosis was supported by genetic analysis of APOE with demonstration of ε4/ε4 genotype, found in about 80% of CAA patients who develop inflammatory changes. In the appropriate clinical setting, MRI demonstration of microbleeds supported by results of genetic analysis of APOE may strongly support the diagnosis of CAA-ri thus avoiding cerebral biopsy.