Navigating Explanatory Multiverse Through Counterfactual Path Geometry

Counterfactual explanations are the de facto standard when tasked with interpreting decisions of (opaque) predictive models. Their generation is often subject to algorithmic and domain-specific constraints -- such as density-based feasibility, and attribute (im)mutability or directionality of change -- that aim to maximise their real-life utility. In addition to desiderata with respect to the counterfactual instance itself, existence of a viable path connecting it with the factual data point, known as algorithmic recourse, has become an important technical consideration. While both of these requirements ensure that the steps of the journey as well as its destination are admissible, current literature neglects the multiplicity of such counterfactual paths. To address this shortcoming we introduce the novel concept of explanatory multiverse that encompasses all the possible counterfactual journeys. We then show how to navigate, reason about and compare the geometry of these trajectories with two methods: vector spaces and graphs. To this end, we overview their spacial properties -- such as affinity, branching, divergence and possible future convergence -- and propose an all-in-one metric, called opportunity potential, to quantify them. Implementing this (possibly interactive) explanatory process grants explainees agency by allowing them to select counterfactuals based on the properties of the journey leading to them in addition to their absolute differences. We show the flexibility, benefit and efficacy of such an approach through examples and quantitative evaluation on the German Credit and MNIST data sets.Comment: Workshop on Counterfactuals in Minds and Machines at 2023 International Conference on Machine Learning (ICML

Livestock overgrazing disrupts the positive associations between soil biodiversity and nitrogen availability

8 páginas.- 4 figuras.- 1 tabla.- 64 referencias.- Additional supporting information may be found online in the Supporting Information sectionLivestock overgrazing influences both microbial communities and nutrient cycling in terrestrial ecosystems. However, the role of overgrazing in regulating the relationship between soil biodiversity and nitrogen availability remains largely unexplored.We performed long-term grazing exclusion experiments across eight sites along precipitation gradient covering three major types of grassland in northern China to compare the linkage between soil microbial diversity and N availability in overgrazed versus non-grazed conditions.We found a significantly positive association between fungal diversity and soil available N in non-grazed grasslands. However, the positive association was absent in overgrazed environments. Bacterial diversity is not related to soil available N in either non-grazed or overgrazed grasslands. Moreover, in bacterial community, we found a positive link between the relative abundance of Actinobacteria with soil available N in non-grazed, but not overgrazed, grasslands. Instead we found the links between relative abundance of Bacteroidetes and Acidobacteria with soil available N in overgrazed grasslands, but not non-grazed, grasslands.Synthesis. Our work provides evidence that the relationships between microbial diversity and ecosystem functions are context-dependent, and so microbial community diversity is likely not the major driver of soil N mineralization in overgrazed grasslands. Our study suggests that high intensity anthropogenic activities in grasslands restrains the capacity of diverse soil microbial communities to sustain ecosystem function, and more broadly the capacity of entire ecosystems to maintain important ecosystem processes such as plant production. Our study also indicates that the fundamental microbial communities associated with N availability change with differing land management strategies (e.g. livestock grazing).National Natural Science Foundation of China, Grant/Award Number: 31772652, U1603235, 31660679 and 31770500; National Key Research and Development Program of China, Grant/Award Number: 2016YFC0500602; Program for Introducing Talents to Universities, Grant/Award Number: B16011; Ministry of Education Innovation Team Development Plan, Grant/Award Number: 2013-373; Innovative Team of Grassland Resources from the Ministry of Education of China, Grant/Award Number: IRT_17R59; Horizon 2020 Framework Program, Grant/Award Number: H2020-MSCA-IF-2016Peer reviewe

Effects of livestock overgrazing on the relationships between plant and microbial diversity across the temperate steppes in northern China

11 páginas.- 3 figuras.- 3 tablas.- 57 referencias.-Livestock overgrazing has led to worldwide grassland degradation, posing a significant threat to plant and soil microbial diversity. However, little is known about whether livestock overgrazing influences plant and soil microbial diversity linkages. We examined relationships between plant and soil microbial beta diversity in eight pairs of ungrazed and overgrazed sites across temperate steppes in northern China. Our results revealed a positive correlation between plant and microbial beta diversity across ungrazed grasslands, and overgrazing did not change this relationship. However, different mechanisms underlay the correlations between plant and microbial beta diversity in ungrazed and overgrazed grasslands. In ungrazed grasslands, plant and microbial diversity associations were maintained mainly due to their similar responses to the shared environmental factors. While in overgrazed grasslands, the maintenance of plant and microbial diversity associations was primarily due to their functional associations. Furthermore, the positive links between plant species and microbial taxa increased in overgrazed grasslands, indicating that more soil microbial taxa form close associations with plant species in overgrazed grasslands. Our work provides new insights regarding the mechanisms of plant and microbial communities that associate under different ecological contexts, ultimately suggesting that the functional associations of plant and microbial communities are tighter as grazing intensifies in grasslands.The work was made possible by the National Natural Science Founda-tion of China (No. 32271642, 32061143027). M.D-B. acknowledges support from the Spanish Ministry of Science and Innovation for the I+D+i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033. M.D-B. is also supported by a project of the Fondo Europeo de Desarrollo Regional (FEDER) and the Consejería de Transformación Económica, Industria, Conocimiento y Universidades of the Junta de Andalucía (FEDER Andalucía 2014-2020 Objetivo temático“01 - Refuerzo de la investigación, el desarrollo tecnológico y la innovación”) associated with the research project P20_00879 (ANDABIOMA).Peer reviewe

Comprehension is a double-edged sword: Over-interpreting unspecified information in intelligible machine learning explanations

Automated decision-making systems are becoming increasingly ubiquitous, which creates an immediate need for their interpretability and explainability. However, it remains unclear whether users know what insights an explanation offers and, more importantly, what information it lacks. To answer this question we conducted an online study with 200 participants, which allowed us to assess explainees’ ability to realise explicated information – i.e., factual insights conveyed by an explanation – and unspecified information – i.e, insights that are not communicated by an explanation – across four representative explanation types: model architecture, decision surface visualisation, counterfactual explainability and feature importance. Our findings uncover that highly comprehensible explanations, e.g., feature importance and decision surface visualisation, are exceptionally susceptible to misinterpretation since users tend to infer spurious information that is outside of the scope of these explanations. Additionally, while the users gauge their confidence accurately with respect to the information explicated by these explanations, they tend to be overconfident when misinterpreting the explanations. Our work demonstrates that human comprehension can be a double-edged sword since highly accessible explanations may convince users of their truthfulness while possibly leading to various misinterpretations at the same time. Machine learning explanations should therefore carefully navigate the complex relation between their full scope and limitations to maximise understanding and curb misinterpretation.ISSN:1071-5819ISSN:1095-930

Biome regulates the effects of long‐term grazing on soil microbial diversity

Abstract Introduction Livestock overgrazing represents one of the most destructive uses of land in terrestrial ecosystems and threatens biodiversity. However, understanding the effects of livestock overgrazing on below‐ground soil microbial diversity is limited, despite soil microbes representing the majority of biodiversity and determining ecosystem functioning. Materials and Methods To investigate the effects of overgrazing on soil microbial richness, a long‐term grazing exclusion experiment was conducted at six sites including three meadow steppes and three typical steppes in northern China. Results Our results revealed that overgrazing decreased bacterial and fungal richness across temperate steppes in northern China, and the biome could regulate the overgrazing effects, especially for fungal richness. Specifically, the negative effects of overgrazing on microbial richness were highly significant in typical steppes while not significant in meadow steppes that contained higher plant diversity and precipitation. Partial least‐squares path model showed that overgrazing affected soil microbial richness in highly complex ways, and the affected pathways were different in meadow steppes and typical steppes. The direct negative effects of grazing and their indirect negative effects via soil properties resulted in a significant decrease in microbial richness in typical steppes. In meadow steppes, the indirect beneficial effects via plant attributes offset the direct negative effects of grazing. Consequently, the soil microbial community in meadow steppe resisted overgrazing disturbance. Conclusion Our study illuminates the complex and highly biome‐dependent grazing effects and pathways on soil microbiota and indicates that meadow steppe may be more resistant or resilient to human disturbance than typical steppe. These findings suggest that different grasslands might be managed differently considering their intrinsic characteristics to help biodiversity conservation. Moreover, future research should focus on the underlying mechanisms of grazing effects on soil microbial richness. Besides grazing‐induced plant and soil traits changes, other potential pathways could strongly influence soil microbial diversity

Exosome-derived circ_0001785 delays atherogenesis through the ceRNA network mechanism of miR-513a- 5p/TGFBR3

Abstract Purpose Endothelial cell dysfunction is a major cause of early atherosclerosis. Although the role of extracellular vesicles in stabilizing atherosclerotic plaques is well established, the effect of circulating exosomes on plaque formation is still unknown. Here, we explored the effect of exosomes on atherosclerosis based on the function that exosomes can act on intercellular communication. Patients and methods: We extracted serum exosomes from the blood of CHD patients (CHD-Exo) and healthy individuals (Con-Exo). The obtained exosomes were co-cultured with human umbilical vein endothelial cells (HUVECs) in vitro. In addition, we determined that circ_0001785 functions as a competing endogenous RNA (ceRNAs) in coronary artery disease by dual luciferase reporter gene analysis. The protective effect of circ_0001785 against endothelial cell injury was also verified using over-expression lentiviral transfection functional assays. In vivo experiments, we injected over-expressed circ_0001785 lentivirus into the tail vein of mice to observe its therapeutic effect on a mouse model of atherosclerosis. Results The vitro co-cultured results showed that the amount of plasma-derived exosomes have an increase in patients with coronary artery disease, and the inflammation and apoptosis of endothelial cells were exacerbated. Over-expression of circ_0001785 reduced endothelial cell injury through the ceRNA network pathway of miR-513a-5p/TGFBR3. Quantitative reverse transcription-polymerase chain reaction identified that the expressed amount of circ_0001785 was reduced in the circulating peripheral blood of CHD patients and increased within human and mouse atherosclerotic plaque tissue. The results of in vivo experiments showed that circ_0001785 reduced aortic endothelial cell injury and the formation of intraplaque neo-vascularization, and enhanced left ventricular diastolic function, thereby delaying the development of atherosclerosis in mice. Conclusion Our results demonstrated a new biomarker, exosome-derived circ_0001785, for atherogenesis, which can reduce endothelial cell injury and thus delay atherogenesis through the miR-513a-5p/TGFBR3 ceRNA network mechanism, providing an exosome-based intervention strategy for atherosclerosis.</jats:p