Measurements of methane flux from northern peatlands to the atmosphere are complicated by high spatial and temporal variability. We quantified the variability of methane flux from two subarctic fens near Schefferville, northern Quebec, using a static chamber technique. Within the seasonal pattern of increasing fluxes associated with the warming of the peat profile, episodic fluxes of methane were observed. One set of episodic events occurred during the spring thaw of the upper layers of the peat, which released methane stored in ice over the winter. The second set, generally of short duration (< 2 d), occurred in mid-summer and appeared to be related primarily to the lowering of the water table. In four of six subjectively-identified, episodic fluxes during the 1990 summer the flux during the episodic event was equal to or greater than the upper 95% confidence level of the three fluxes before and after the event (t-statistic probabilities ranged from < 0.001 to 0.038). Mechanisms to account for these episodic fluxes of methane include increased methane diffusivity, removal of overburden pressure and reduced rates of methane consumption in the surface layers of the peat. Omission of these episodic fluxes could lower estimates of seasonal methane emissions by 7–22%. Key words: Peatlands, fens, methane

We present WISEA J114724.10−204021.3, a young, low-mass, high probability member of the TW Hya association. WISEA J114724.10−204021.3 was discovered based on its red AllWISE color (W1−W2 = 0.63 mag) and extremely red 2MASS J − K S color (> 2.64 mag), the latter of which is confirmed with near-infrared photometry from the VISTA Hemisphere Survey (J − K S = 2.57±0.03). Follow-up near-infrared spectroscopy shows a spectral type of L7 ± 1 as well as several spectroscopic indicators of youth. These include a peaked H-band shape and a steeper K-band slope, traits typically attributed to low surface gravity. The sky position, proper motion, and distance estimates of WISEA J114724.10−204021.3 are all consistent with membership in the ∼10 Myr old TW Hya association. Using the age of the TW Hya association and evolutionary models, we estimate the mass of WISEA J114724.10−204021.3 to be 5−13 M Jup , making it one of the youngest and lowest mass free-floating objects yet discovered in the Solar neighborhood.

Young brown dwarfs share many properties with directly imaged giant extrasolar planets. They therefore provide unique laboratories for investigating the full range of temperature and mass encompasses by the growing collection of planets discovered outside our Solar System. Furthermore, if they can be tied to a particular group of coeval stars, they also provide vital anchor points for low-mass empirical isochrones. We have developed a novel procedure for identifying such objects based on their unique 2MASS and AllWISE colors. Using our search criteria, we have identified 50 new, late-type L dwarf candidates, 47 of which are spectroscopically confirmed as L dwarfs with follow-up near-infrared spectroscopy. We evaluate the potential membership of these objects in nearby, young moving groups using their proper motions, photometric distance estimates, and spectroscopic indicators of youth, and find seven likely L-type members belonging to the β Pictoris moving group, the AB Doradus moving group, the Tucana-Horologium association, or the Argus association, in addition to several lower probability members. Also found are two late-type (L5 and L6) potential members of the nearby Hyades cluster (WISEA J043642.75+190134.8 and WISEA J044105.56+213001.5).

This paper will describe the benefits of incorporating software Time and Space Partitioning (TSP), based upon the aeronautic IMA concept, into the spacecraft avionics architecture to manage the growth of mission functions implemented in the on-board software. The paper addresses how TSP can be used to safely integrate applications of different criticality and security classifications, and how incremental validation is supported to control the impact of software modifications to the system.

The ARINC 653 specification defines the functionality that an Operating System (OS) must guarantee to enforce robust spatial and temporal partitioning as well as an avionics application programming interface for the system.The standard application interface -the ARINC 653 Application Executive (APEX) -is defined as a set of software services a compliant OS must provide to avionics application developers. The ARINC 653 specification defines the interfaces and the behavior of the APEX but leaves implementation details to OS vendors. This paper describes an OS independent design approach of a Portable APEX interface. POSIX, as a programming interface available on a wide range of modern OS, will be used to implement the APEX layer. This way the standardization of the APEX is taken a step further: not only the definition of services is standardized but also its interface to the underlying OS. Therefore, the APEX operation does not depend on a particular OS but relies on a well defined set of standardized components. Inter-partition communication Interfaces:This module implements the communication means between processes in different partitions. All inter-partition communication is conducted via messages. When sent by user applications, messages are copied into local buffers. The underlying PMK is then responsible for actually transferring a given message to the corresponding buffer in the target partition, providing the physical means to activate message exchange between the source process and the outer destination.