Time-varying graph representation learning via higher-order skip-gram with negative sampling

Representation learning models for graphs are a successful family of techniques that project nodes into feature spaces that can be exploited by other machine learning algorithms. Since many real-world networks are inherently dynamic, with interactions among nodes changing over time, these techniques can be defined both for static and for time-varying graphs. Here, we show how the skip-gram embedding approach can be generalized to perform implicit tensor factorization on different tensor representations of time-varying graphs. We show that higher-order skip-gram with negative sampling (HOSGNS) is able to disentangle the role of nodes and time, with a small fraction of the number of parameters needed by other approaches. We empirically evaluate our approach using time-resolved face-to-face proximity data, showing that the learned representations outperform state-of-the-art methods when used to solve downstream tasks such as network reconstruction. Good performance on predicting the outcome of dynamical processes such as disease spreading shows the potential of this method to estimate contagion risk, providing early risk awareness based on contact tracing data. Supplementary information: The online version contains supplementary material available at 10.1140/epjds/s13688-022-00344-8

Explainability Methods for Natural Language Processing: Applications to Sentiment Analysis

Sentiment analysis is the process of classifying natural lan-guage sentences as expressing positive or negative sentiments, and it is a crucial task where the explanation of a prediction might arguably be as necessary as the prediction itself. We analysed di fierent explanation techniques, and we applied them to the classification task of Sentiment Analysis. We explored how attention-based techniques can be exploited to extract meaningful sentiment scores with a lower computational cost than existing XAI methods

Genomic approaches to unveil the physiological pathways activated in Arabidopsis treated with plant-derived raw extracts

DNA microarrays can be used to obtain a fingerprint of the transcriptional status of the plant or cell under a given condition and may be useful for characterising which genes respond, either by induction or repression, to novel stimuli or specific treatments. An in-depth bioinformatical analysis of all the data produced by microarrays can further highlight the metabolic or functional pathways most affected by the treatment. This approach has been used to investigate the effects induced by the treatment of different plant-derived raw materials, provided by Valagro SpA, on Arabidopsis seedlings. A clear example is represented by treatment with a raw plant-derived protein extract (VAL-P01). In this case the treatment induced genes related to ABA and osmotic stress treatment. We therefore demonstrated that VAL-P01 was able to mimic in planta the same pattern of responses linked to ABA treatment or osmotic stress, making the plant stronger against possible further stresses. Another plant extract, VAL-P02, was shown to be significantly altering the transcription of senescence genes, making it an ideal candidate adjuvant for the prolonged shelf-life of vegetal products

Mapping urban socioeconomic inequalities in developing countries through Facebook advertising data

Ending poverty in all its forms everywhere is the number one Sustainable Development Goal of the UN 2030 Agenda. To monitor the progress toward such an ambitious target, reliable, up-to-date and fine-grained measurements of socioeconomic indicators are necessary. When it comes to socioeconomic development, novel digital traces can provide a complementary data source to overcome the limits of traditional data collection methods, which are often not regularly updated and lack adequate spatial resolution. In this study, we collect publicly available and anonymous advertising audience estimates from Facebook to predict socioeconomic conditions of urban residents, at a fine spatial granularity, in four large urban areas: Atlanta (USA), Bogotá (Colombia), Santiago (Chile), and Casablanca (Morocco). We find that behavioral attributes inferred from the Facebook marketing platform can accurately map the socioeconomic status of residential areas within cities, and that predictive performance is comparable in both high and low-resource settings. Our work provides additional evidence of the value of social advertising media data to measure human development and it also shows the limitations in generalizing the use of these data to make predictions across countries

Transcript profiling of chitosan-treated Arabidopsis seedlings

In nature, plants can recognize potential pathogens, thus activating intricate networks of defense signals and reactions. Inducible defense is often mediated by the detection of microbe or pathogen associated molecular pattern elicitors, such as flagellin and chitin. Chitosan, the deacetylated form of chitin, plays a role in inducing protection against pathogens in many plant species. We evaluated the ability of chitosan to confer resistance to Botrytis cinerea in Arabidopsis leaves. We subsequently treated Arabidopsis seedlings with chitosan and carried out a transcript profiling analysis using both ATH1 GeneChip microarrays and quantitative RT-PCR. The results showed that defense response genes, including camalexin biosynthesis genes, were up-regulated by chitosan, both in wild-type and in the chitin-insensitive cerk1 mutant, indicating that chitosan is perceived through a CERK1-independent pathway

Gender gaps in urban mobility

Abstract Mobile phone data have been extensively used to study urban mobility. However, studies based on gender-disaggregated large-scale data are still lacking, limiting our understanding of gendered aspects of urban mobility and our ability to design policies for gender equality. Here we study urban mobility from a gendered perspective, combining commercial and open datasets for the city of Santiago, Chile. We analyze call detail records for a large cohort of anonymized mobile phone users and reveal a gender gap in mobility: women visit fewer unique locations than men, and distribute their time less equally among such locations. Mapping this mobility gap over administrative divisions, we observe that a wider gap is associated with lower income and lack of public and private transportation options. Our results uncover a complex interplay between gendered mobility patterns, socio-economic factors and urban affordances, calling for further research and providing insights for policymakers and urban planners

The effect of a complete fertilizer for leafy vegetables production in family and urban gardens

The home vegetables cultivation in family or urban gardens for self -consumption is mainly performed as a hobby but without following the good agricultural practices. Home gardening is often carried out by inexperienced people, which may lead to wrong fertilization. In this work, a fertilizer was evaluated for providing the mineral nutrients required from vegetables and stimulate the nutrient use efficiency in the plant. The commercial product ONE\uae, commercialized by Valagro S.p.A., was tested on two different leafy vegetables, Lactucasativa L. and Cichoriumendivia L. In order to discriminate the nutritional effect from the biostimulant effects, ONE\uae treatments were compared to a control added with the minimum crops requirements and to solutions containing the same concentrations of macro-nutrients as in ONE\uae. Results showed that ONE\uae treatments were able to speed up the growing rate of plants that reached the commercial maturity earlier. The chlorophyll content was higher in ONE\uae treatments, showing a positive effect on the visual appearance of the vegetables. Nitrate content in lettuce was below 500 mg/kg fresh weight, a value much lower than the commercialization law limits. Treatment caused a higher increase of reducing sugars in lettuce respect to endive. In lettuce the sucrose content was higher in outer leaves compared to the inner leaves, while opposite results were found for total sugars. In endive sucrose and total sugar were lower in ONE\uae treatments compared to control. In conclusion, considering yield and quality parameters, ONE\uae was effective in improving the quality of the leafy vegetables tested

The Debrisoft ® monofilament debridement pad for use in acute or chronic wounds: A NICE medical technology guidance

As part of its Medical Technology Evaluation Programme, the National Institute for Health and Care Excellence (NICE) invited a manufacturer to provide clinical and economic evidence for the evaluation of the Debrisoft ® monofilament debridement pad for use in acute or chronic wounds. The University of Birmingham and Brunel University, acting as a consortium, was commissioned to act as an External Assessment Centre (EAC) for NICE, independently appraising the submission. This article is an overview of the original evidence submitted, the EAC’s findings and the final NICE guidance issued. The sponsor submitted a simple cost analysis to estimate the costs of using Debrisoft® to debride wounds compared with saline and gauze, hydrogel and larvae. Separate analyses were conducted for applications in home and applications in a clinic setting. The analysis took an UK National Health Service (NHS) perspective. It incorporated the costs of the technologies and supplementary technologies (such as dressings) and the costs of their application by a district nurse. The sponsor concluded that Debrisoft® was cost saving relative to the comparators. The EAC made amendments to the sponsor analysis to correct for errors and to reflect alternative assumptions. Debrisoft® remained cost saving in most analyses and savings ranged from £77 to £222 per patient compared with hydrogel, from £97 to £347 compared with saline and gauze, and from £180 to £484 compared with larvae depending on the assumptions included in the analysis and whether debridement took place in a home or clinic setting. All analyses were severely limited by the available data on effectiveness, in particular a lack of comparative studies and that the effectiveness data for the comparators came from studies reporting different clinical endpoints compared with Debrisoft®. The Medical Technologies Advisory Committee made a positive recommendation for adoption of Debrisoft® and this has been published as a NICE medical technology guidance (MTG17).The Birmingham and Brunel Consortium is funded by NICE to act as an External Assessment Centre for the Medical Technologies Evaluation Programme