Dependability of Alternative Computing Paradigms for Machine Learning: hype or hope?

Today we observe amazing performance achieved by Machine Learning (ML); for specific tasks it even surpasses human capabilities. Unfortunately, nothing comes for free: the hidden cost behind ML performance stems from its high complexity in terms of operations to be computed and the involved amount of data. For this reasons, custom Artificial Intelligence hardware accelerators based on alternative computing paradigms are attracting large interest. Such dedicated devices support the energy-hungry data movement, speed of computation, and memory resources that MLs require to realize their full potential. However, when ML is deployed on safety-/mission-critical applications, dependability becomes a concern. This paper presents the state of the art of custom Artificial Intelligence hardware architectures for ML, here Spiking and Convolutional Neural Networks, and shows the best practices to evaluate their dependability

Biotic and abiotic predictors of potential N2O emissions from denitrification in Irish grasslands soils: A national-scale field study

Publication history: Accepted - 18 March 2022; Published - 25 March 2022.Large-scale information regarding nitrous oxide (N2O) emissions is needed as an evidence base to underpin land use policy and mitigation approaches. However, the highly variable rates of denitrification make the prediction of N2O emission demanding. Here, we evaluated the role of abiotic and biotic factors on the potential denitrification of Irish soils, in order to identify the key factors regulating potential N2O emissions at a large scale. To do so, we collected 136 soil samples from 32 sites across Ireland, and characterised the soil physico-chemical properties, the prokaryotic and fungal community composition, the abundance of N-cycling genes and evaluated the soil potential nitrification, denitrification and end product N2O/(N2O + N2). We found large differences in soil potential denitrification between sites (up to 41.5 mg N2O–N kg 1 soil day 1) with most of the emissions released in the form of N2O rather than N2. Soils with highest potential nitrification rates also exhibited the highest potential denitrification rates, and similar parameters were linked to both processes. The factors most predictive of soil potential denitrification were soil physico-chemical properties and the prokaryotic community composition. Soil phosphorus content was as important for predicting potential denitrification as was pH and total nitrogen. Soil microbial community structure, rather than denitrifier abundance, was an important predictor of the potential denitrification and the end-product N2O/(N2O + N2). The prokaryotic community composition was more strongly associated with denitrification rates and the resulting end-products than fungal communities. Increased relative abundance of the prokaryotic phyla Actinobacteriota and Crenarchaeota, were positively correlated to complete denitrification. Altogether, these results lay the foundation for a better understanding of the key factors regulating the potential denitrification in soils and identify important properties that enhance prediction of the potential denitrification at larger scales.This research and CD, JR and PRP were financially supported under the National Development Plan, through the Research Stimulus Fund, administered by the Irish Department of Agriculture, Food and the Marine (Grant number 15S655: MINE project)

Linking long‑term soil phosphorus management to microbial communities involved in nitrogen reactions

The influence of soil phosphorous (P) content on the N-cycling communities and subsequent effects on N2O emissions remains unclear. Two laboratory incubation experiments were conducted on soils collected from a long-term (est. 1995) P-addition field trial sampled in summer 2018 and winter 2019. Incubations were treated with a typical field amendment rate of N as well as a C-amendment to stimulate microbial activity. Throughout both incubations, soil subsamples were collected prior to fertiliser amendment and then throughout the incubations, to quantify the abundance of bacteria (16S rRNA), fungi (ITS) and Thaumarcheota (16S rRNA) as well as functional guilds of genes involved in nitrification (bacterial and archaeal amoA, and comammox) and denitrification (nirS, nirK, nosZ clade I and II) using quantitative PCR (qPCR). We also evaluated the correlations between each gene abundance and the associated N2O emissions depending on P-treatments. Our results show that long-term P-application influenced N-cycling genes abundance differently. Except for comammox, overall nitrifiers’ genes were most abundant in low P while the opposite trend was found for denitrifiers’ genes. C and N-amendments strongly influenced the abundance of most genes with changes observed as soon as 24 h after application. ITS was the only gene correlated to N2O emissions in the low P-soils while microbes were mostly correlated to emissions in high P, suggesting possible changes in the organisms involved in N2O production depending on soil P-content. This study highlights the importance of long-term P addition on shaping the microbial community function which in turn stimulates a direct impact on the subsequent N emissions

Myristate and the ecology of AM fungi : significance, opportunities, applications and challenges

A recent study by Sugiura and coworkers reported the nonsymbiotic growth and spore production of an arbuscular mycorrhizal (AM) fungus, Rhizophagus irregularis, when the fungus received an external supply of certain fatty acids, myristates (C:14). This discovery follows the insight that AM fungi receive fatty acids from their hosts when in symbiosis. If this result holds up and can be repeated under nonsterile conditions and with a broader range of fungi, it has numerous consequences for our understanding of AM fungal ecology, from the level of the fungus, at the plant community level, and to functional consequences in ecosystems. In addition, myristate may open up several avenues from a more applied perspective, including improved fungal culture and supplementation of AM fungi or inoculum in the field. We here map these potential opportunities, and additionally offer thoughts on potential risks of this potentially new technology. Lastly, we discuss the specific research challenges that need to be overcome to come to an understanding of the potential role of myristate in AM ecology

Long-term actuation demonstration of RF-MEMS switches for space applications

International audienc

Biotic and abiotic predictors of potential N2O emissions from denitrification in Irish grasslands soils: A national-scale field study

International audienc