Expert-Augmented Machine Learning

Machine Learning is proving invaluable across disciplines. However, its success is often limited by the quality and quantity of available data, while its adoption by the level of trust that models afford users. Human vs. machine performance is commonly compared empirically to decide whether a certain task should be performed by a computer or an expert. In reality, the optimal learning strategy may involve combining the complementary strengths of man and machine. Here we present Expert-Augmented Machine Learning (EAML), an automated method that guides the extraction of expert knowledge and its integration into machine-learned models. We use a large dataset of intensive care patient data to predict mortality and show that we can extract expert knowledge using an online platform, help reveal hidden confounders, improve generalizability on a different population and learn using less data. EAML presents a novel framework for high performance and dependable machine learning in critical applications

Long-term tillage, straw, and N rate effects on quantity and quality of organic C and N in a Black Chernozemic soil

Non-Peer Reviewe

Influence of long-term application of N and S fertilizers (1980-2002) and liming in 1992 on dry matter yield of grass and soil properties in a Dark Gray Chernozem in north-central Saskatchewan

Non-Peer ReviewedMost soils are deficient in plant-available N in the Prairie Provinces of Canada, and in the Parkland region, many soils are also insufficient in available S for high crop yields. Long-term field experiments, initiated in 1980 and 1996 on a Dark Gray Chernozem loam soil at Canwood in north-central Saskatchewan, were conducted to determine the effects of N, S and lime application and forage removal on forage dry matter yield (DMY) and soil properties. The results indicated that application of N or S alone had only a little effect on DMY, while application of N together with S substantially increased DMY. Decline of soil pH by annual applications of N and S fertilizers mainly happened in the 0-5 cm layer. In layers below 10 cm, soil pH tended to increase with N or NS fertilization. Surface application of granular lime increased soil pH mainly in the 0-5 cm layer, and the high pH was maintained for at least 9 years. The TOC and TN mass in the 0-7.5 cm soil layer increased with annual applications of N and S fertilizers, and the increase was more pronounced with application of N and S together. In the subsoil layers, the N treatment tended to decrease, but the NS treatment tended to increase the TOC and TN. This suggests that application of N and S together was more effective in increasing C and N sequestration in a soil deficient in both N and S

Long-term tillage, straw, and N rate effects on quantity and quality of organic C and N in a Gray Luvisol soil

Non-Peer Reviewe

Photometric Variability in the Ultracool Dwarf BRI 0021-0214: Possible Evidence for Dust Clouds

We report CCD photometric monitoring of the nonemission ultracool dwarf BRI 0021-0214 (M9.5) obtained during 10 nights in 1995 November and 4 nights in 1996 August, with CCD cameras at 1 m class telescopes on the observatories of the Canary Islands. We present differential photometry of BRI 0021-0214, and we report significant variability in the I-band light curve obtained in 1995. A periodogram analysis finds a strong peak at a period of 0.84 day. This modulation appears to be transient because it is present in the 1995 data but not in the 1996 data. We also find a possible period of 0.20 day, which appears to be present in both the 1995 and 1996 datasets. However, we do not find any periodicity close to the rotation period expected from the spectroscopic rotational broadening (< 0.14 day). BRI 0021-0214 is a very inactive object, with extremely low levels of Halpha and X-ray emission. Thus, it is unlikely that magnetically induced cool spots can account for the photometric variability. The photometric variability of BRI 0021-0214 could be explained by the presence of an active meteorology that leads to inhomogeneous clouds on the surface. The lack of photometric modulation at the expected rotational period suggests that the pattern of surface features may be more complicated than previously anticipated.Comment: Accepted for publication in ApJ. 26 pages, 13 figures include

Context and strain-dependent behavioral response to stress

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Enabling the Reuse of Stored Model Transformations Through Annotations

International audienceWith the increasing adoption of MDE, model transformations , one of its core concepts together with metamodeling, stand out as a valuable asset. Therefore, a mechanism to annotate and store existing model transformations appears as a critical need for their efficient exploitation and reuse. Unfortunately, although several reuse mechanisms have been proposed for software artifacts in general and models in particular , none of them is specially tailored to the domain of model transformations. In order to fill this gap, we present here such a mechanism. Our approach is composed by two elements 1) a new DSL specially conceived for describing model transformations in terms of their functional and non-functional properties 2) a semi-automatic process for annotating and querying (repositories of) model transformations using as criteria the properties of our DSL. We validate the feasibility of our approach through a prototype implementation that integrates our approach in a GitHub repository

Support varieties for selfinjective algebras

Support varieties for any finite dimensional algebra over a field were introduced by Snashall-Solberg using graded subalgebras of the Hochschild cohomology. We mainly study these varieties for selfinjective algebras under appropriate finite generation hypotheses. Then many of the standard results from the theory of support varieties for finite groups generalize to this situation. In particular, the complexity of the module equals the dimension of its corresponding variety, all closed homogeneous varieties occur as the variety of some module, the variety of an indecomposable module is connected, periodic modules are lines and for symmetric algebras a generalization of Webb's theorem is true

Characteristics of tropospheric ozone depletion events in the Arctic spring: analysis of the ARCTAS, ARCPAC, and ARCIONS measurements and satellite BrO observations

Arctic ozone depletion events (ODEs) are caused by halogen catalyzed ozone loss. In situ chemistry, advection of ozone-poor air mass, and vertical mixing in the lower troposphere are important factors affecting ODEs. To better characterize the ODEs, we analyze the combined set of surface, ozonesonde, and aircraft in situ measurements of ozone and bromine compounds during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS), the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC), and the Arctic Intensive Ozonesonde Network Study (ARCIONS) experiments (April 2008). Tropospheric BrO columns retrieved from satellite measurements and back trajectory calculations are also used to investigate the characteristics of observed ODEs. In situ observations from these field experiments are inadequate to validate tropospheric BrO columns derived from satellite measurements. In view of this difficulty, we construct an ensemble of tropospheric column BrO estimates from two satellite (OMI and GOME-2) measurements and with three independent methods of calculating stratospheric BrO columns. Furthermore, we select analysis methods that do not depend on the absolute magnitude of column BrO, such as time-lagged correlation analysis of ozone and tropospheric column BrO, to understand characteristics of ODEs. Time-lagged correlation analysis between in situ (surface and ozonesonde) measurements of ozone and satellite derived tropospheric BrO columns indicates that the ODEs are due to either local halogen-driven ozone loss or short-range (∼1 day) transport from nearby regions with ozone depletion. The effect of in situ ozone loss is also evident in the diurnal variation difference between low (10th and 25th percentiles) and higher percentiles of surface ozone concentrations at Alert, Canada. Aircraft observations indicate low-ozone air mass transported from adjacent high-BrO regions. Correlation analyses of ozone with potential temperature and time-lagged tropospheric BrO column show that the vertical extent of local ozone loss is surprisingly deep (1–2 km) at Resolute and Churchill, Canada. The unstable boundary layer during ODEs at Churchill could potentially provide a source of free-tropospheric BrO through convective transport and explain the significant negative correlation between free-tropospheric ozone and tropospheric BrO column at this site