Making Neural Networks Interpretable with Attribution: Application to Implicit Signals Prediction

Explaining recommendations enables users to understand whether recommended items are relevant to their needs and has been shown to increase their trust in the system. More generally, if designing explainable machine learning models is key to check the sanity and robustness of a decision process and improve their efficiency, it however remains a challenge for complex architectures, especially deep neural networks that are often deemed "black-box". In this paper, we propose a novel formulation of interpretable deep neural networks for the attribution task. Differently to popular post-hoc methods, our approach is interpretable by design. Using masked weights, hidden features can be deeply attributed, split into several input-restricted sub-networks and trained as a boosted mixture of experts. Experimental results on synthetic data and real-world recommendation tasks demonstrate that our method enables to build models achieving close predictive performances to their non-interpretable counterparts, while providing informative attribution interpretations.Comment: 14th ACM Conference on Recommender Systems (RecSys '20

Water Mass Analysis of the 2018 US GEOTRACES Pacific Meridional Transect (GP15)

A water mass analysis is a tool for interpreting the effect of ocean mixing on the distributions of trace elements and isotopes (TEI\u27s) along an oceanographic transect. The GEOTRACES GP15 transect along 152°W covers a wide range in latitude from Alaska to Tahiti. Our objective is to present the nutrients and hydrography of GP15 and quantify the distributions of water masses to support our understanding of TEI distributions along GP15. We used a modified Optimum Multiparameter (OMP) analysis to determine the distributions of water masses with high importance to nutrient and hydrographic features in the region. In the thermocline, our results indicated the dominance of Pacific Subarctic Upper Water (PSUW) in the subpolar gyre, Eastern North Pacific Central Water (ENPCW) in the northern subpolar gyre, and Equatorial Subsurface Water (ESSW) in the equatorial region. South Pacific Subtropical Water (SPSTW) dominated the top of the thermocline in the southern subtropical gyre, while South Pacific Central Water (SPCW) dominated the lower thermocline. Antarctic Intermediate Water (AAIW), Equatorial Intermediate Water (EqIW), and North Pacific Intermediate Water (NPIW) in the southern hemisphere, equatorial region, and northern hemisphere, respectively, occupied waters just below the thermocline. Dominant water masses in the deep waters of the southern hemisphere include Upper Circumpolar Deep Water (UCDW) and Lower Circumpolar Deep Water (LCDW) with minimal contributions from Antarctic Bottom Water (AABW). Pacific Deep Water (PDW) dominated the deep water in the northern hemisphere. Our results align well with literature descriptions of these water masses and related circulation patterns

Transcriptional Reversion of Cardiac Myocyte Fate During Mammalian Cardiac Regeneration

Rationale: Neonatal mice have the capacity to regenerate their hearts in response to injury, but this potential is lost after the first week of life. The transcriptional changes that underpin mammalian cardiac regeneration have not been fully characterized at the molecular level. Objective: The objectives of our study were to determine whether myocytes revert the transcriptional phenotype to a less differentiated state during regeneration and to systematically interrogate the transcriptional data to identify and validate potential regulators of this process. Methods and Results: We derived a core transcriptional signature of injury-induced cardiac myocyte (CM) regeneration in mouse by comparing global transcriptional programs in a dynamic model of in vitro and in vivo CM differentiation, in vitro CM explant model, as well as a neonatal heart resection model. The regenerating mouse heart revealed a transcriptional reversion of CM differentiation processes, including reactivation of latent developmental programs similar to those observed during destabilization of a mature CM phenotype in the explant model. We identified potential upstream regulators of the core network, including interleukin 13, which induced CM cell cycle entry and STAT6/STAT3 signaling in vitro. We demonstrate that STAT3/periostin and STAT6 signaling are critical mediators of interleukin 13 signaling in CMs. These downstream signaling molecules are also modulated in the regenerating mouse heart. Conclusions: Our work reveals new insights into the transcriptional regulation of mammalian cardiac regeneration and provides the founding circuitry for identifying potential regulators for stimulating heart regeneration. Keywords: cardiac myocyte; gene expression; growth factors/cytokines; myogenesis regenerationNational Institutes of Health (U.S.) (Grant F32HL104913)National Institutes of Health (U.S.) (Grant K99HL122514)National Institutes of Health (U.S.) (Grant U01HL098179)Natioanal Science Foundation (U.S.) (Grant CBET-0939511

Transcriptional reversion of cardiac myocyte fate during mammalian cardiac regeneration

Rationale: Neonatal mice have the capacity to regenerate their hearts in response to injury, but this potential is lost after the first week of life. The transcriptional changes that underpin mammalian cardiac regeneration have not been fully characterized at the molecular level. Objective: The objectives of our study were to determine whether myocytes revert the transcriptional phenotype to a less differentiated state during regeneration and to systematically interrogate the transcriptional data to identify and validate potential regulators of this process. Methods and Results: We derived a core transcriptional signature of injury-induced cardiac myocyte (CM) regeneration in mouse by comparing global transcriptional programs in a dynamic model of in vitro and in vivo CM differentiation, in vitro CM explant model, as well as a neonatal heart resection model. The regenerating mouse heart revealed a transcriptional reversion of CM differentiation processes, including reactivation of latent developmental programs similar to those observed during destabilization of a mature CM phenotype in the explant model. We identified potential upstream regulators of the core network, including interleukin 13, which induced CM cell cycle entry and STAT6/STAT3 signaling in vitro. We demonstrate that STAT3/periostin and STAT6 signaling are critical mediators of interleukin 13 signaling in CMs. These downstream signaling molecules are also modulated in the regenerating mouse heart. Conclusions: Our work reveals new insights into the transcriptional regulation of mammalian cardiac regeneration and provides the founding circuitry for identifying potential regulators for stimulating heart regeneration.Stem Cell and Regenerative Biolog