Drift Correction Methods for gas Chemical Sensors in Artificial Olfaction Systems: Techniques and Challenges

In this chapter the authors introduce the main challenges faced when developing drift correction techniques and will propose a deep overview of state-of-the-art methodologies that have been proposed in the scientific literature trying to underlying pros and cons of these techniques and focusing on challenges still open and waiting for solution

EVALUATION OF ANTIBIOTIC RESISTANCE PROFILES OF HALOBACTERIA ISOLATED FROM THE FOOD CHAIN

L’insorgenza e la diffusione dell’antibiotico resistenza sta diventando un problema a livello mondiale. Molti sono gli ambienti in cui può avvenire tale diffusione, ma una delle principali vie di trasmissione passa attraverso la catena alimentare. Infatti, l’utilizzo di sostanze antimicrobiche è largamente diffuso negli allevamenti di animali ad uso alimentare e in agricoltura. In particolare, negli allevamenti gli antibiotici non solo vengono usati per trattare eventuali patologie, ma anche come profilassi e come promotori di crescita. Di conseguenza, questo uso a volte sconsiderato ha portato all’insorgenza di batteri resistenti a tali sostanze. Un ruolo fondamentale nella trasmissione e diffusione di tali resistenze a livello alimentare è svolto da batteri non patogeni che sono parte del naturale microbiota degli alimenti. Questi microorganismi infatti, pur non essendo essi stessi nocivi per l’uomo, possono fungere da reservoir di antibiotico resistenze per eventuali batteri patogeni. I batteri che generalmente svolgono questo ruolo sono i batteri lattici. Per questo motivo molto importante è stato identificare e studiare l’antibiotico resistenza anche di tali microorganismi. Negli ultimi anni, tuttavia, c’è stato un crescente interesse per un’altra classe di microorganismi, chiamata Haloarchaea o alobatteri o archaea alofili, poiché la loro presenza è stata rilevata in alimenti particolarmente salati. Dal momento che in letteratura ci sono pochi lavori che studiano i profili di antibiotico resistenza di tali microorganismi e, comunque, tali profili non sono stati studiati su un numero significativo di microorganismi appartenenti alla stessa specie, il presente lavoro di tesi è volto a definire il profilo di antibiotico resistenza del capostipite degli archaea alofili, che è l’Halobacterium salinarum, verificare se ci sono ceppi che presentano antibiotico resistenze e controllare se tali resistenze possono essere trasferite a batteri patogeni.Antimicrobial resistance is now widely acknowledged as a major global public health challenge. There are many environments through which the transmission and diffusion of antibiotic resistance could happen, but one of the main routes of transmission is the food chain. As a matter of fact, antibiotic use is widely spread in animal husbandry and in agriculture. In particular, in animal husbandry antimicrobials have been used both for therapeutic reasons and as growth promoters. As a consequence, a selective pressure on pathogenic and commensal bacteria of animal origin has been exerted during the time, leading to the onset of microorganisms resistant to such compounds. A pivotal role in the spread in the food chain of antibiotic resistance has been played by non-pathogenic bacteria present in food. These microorganisms are not harmful for humans, but they could represent a reservoir of antibiotic resistance for foodborne pathogenic bacteria. Usually lactic acid bacteria play this role, since they are present in all fermented food. For this reason, the antibiotic resistance profile of lactic acid bacteria has been assessed. In recent years, another class of microorganisms called halophilic archaea have raised an increasing scientific interest, since they have been found in the human intestinal mucosa as well as in foods such as salted codfish and fermented Asiatic seafood. As a few papers have studied the antibiotic resistance profiles of halophilic archaea, and the only present do not consider a statistically significant number of microorganisms belonging to the same species, the aim of the present work is to define the antibiotic resistance profile of the major exponent of halophilic archaea, named Halobacterium salinarum, and consequently to verify if some strains present antibiotic resistances and if they can transfer these resistances to bacteria present in the food chain

Towards Drift Correction in Chemical Sensors Using an Evolutionary Strategy

Gas chemical sensors are strongly affected by the so-called drift, i.e., changes in sensors' response caused by poisoning and aging that may significantly spoil the measures gathered. The paper presents a mechanism able to correct drift, that is: delivering a correct unbiased fingerprint to the end user. The proposed system exploits a state-of-the-art evolutionary strategy to iteratively tweak the coefficients of a linear transformation. The system operates continuously. The optimal correction strategy is learnt without a-priori models or other hypothesis on the behavior of physical-chemical sensors. Experimental results demonstrate the efficacy of the approach on a real problem

Increasing pattern recognition accuracy for chemical sensing by evolutionary based drift compensation

Artificial olfaction systems, which mimic human olfaction by using arrays of gas chemical sensors combined with pattern recognition methods, represent a potentially low-cost tool in many areas of industry such as perfumery, food and drink production, clinical diagnosis, health and safety, environmental monitoring and process control. However, successful applications of these systems are still largely limited to specialized laboratories. Sensor drift, i.e., the lack of a sensor's stability over time, still limits real in dustrial setups. This paper presents and discusses an evolutionary based adaptive drift-correction method designed to work with state-of-the-art classification systems. The proposed approach exploits a cutting-edge evolutionary strategy to iteratively tweak the coefficients of a linear transformation which can transparently correct raw sensors' measures thus mitigating the negative effects of the drift. The method learns the optimal correction strategy without the use of models or other hypotheses on the behavior of the physical chemical sensors

Nanostructured metal oxide gas sensors, a survey of applications carried out at SENSOR lab, brescia (Italy) in the security and food quality fields

8partially_openopenPonzoni A. ; Comini E. ; Concina I. ; Ferroni M. ; Falasconi M. ; Gobbi E.; Sberveglieri V. ; Sberveglieri G.Ponzoni, Andrea; Comini, Elisabetta; Concina, Isabella; Ferroni, Matteo; Falasconi, Matteo; Gobbi, Emanuela; Sberveglieri, V.; Sberveglieri, Giorgi

Quantities, determinants, and awareness of households' food waste in Italy: A comparison between diary and questionnaires quantities

Food waste at the household level accounts for a significant share of total food waste in developed economies, according to the Food and Agriculture Organization. Studies have shown that this share varies between 0.3 kg to 4.5 kg per person per week, depending on the definitions and methodologies applied. In Italy, quantities, behaviors, and attitudes regarding food waste have been solely explored through the use of questionnaires, typically leading to discrepant values of food waste. In this study, we estimate and analyse the determinants of food waste over a 388 units' panel spread over the national territory, through a diary and questionnaire study. Moreover, by comparing food waste value that was declared in questionnaires and reported in diaries, we confirm that the awareness of food waste quantities is heavily biased. The results confirm that the average food waste value is significantly higher when gathered through diaries, while questionnaires are able to catch less than one-third of food waste determinants

Tell Me What You Waste and I’ll Tell You Who You Are: An Eight-Country Comparison of Consumers’ Food Waste Habits

Using an original survey conducted in eight countries in 2021 (Canada, China, Germany, Italy, Russia, Spain, the UK, and the USA), this study explored the relationship between household food waste and dietary habits through a cross-country comparative perspective. In total, 8000 questionnaires were recorded from samples representative of the adult population of each country through an online survey conducted between the 13th and the 24th of August. The questionnaires were developed from the Waste Watcher International Observatory on Food and Sustainability, an international study of the social, behavioral, and lifestyle dynamics behind household food waste. The relationships between the per capita self-reported amount of food waste (expressed in kilocalories) and self-declared dietary habits (traditional, healthy and sustainable, vegetarian, smart, and confused) were estimated using multiple linear regression models. The results showed that smart diets are associated with higher values of food waste in Canada, Spain, the UK, and the USA. Vegetarian diets are associated with lower food waste values in China, Germany, the UK, and the USA, but not in Italy, Russia, and Spain. The share of the population adopting a smart diet was, on average, 2.7% of the sample; therefore, interventions for food waste reduction should focus on these specific types of consumers, who are often associated with larger amounts of food waste

Exploring the nexus between social and environmental sustainability within EU organic agriculture : a systematic literature review

The European Union’s Farm-to-Fork Strategy and Green Deal underscore organic farming’s critical role in promoting sustainability and addressing socio-economic issues, including precarious, seasonal, and undeclared labor. The EU’s objective to have at least 25% of the agricultural land dedicated to organic farming by 2030 highlights the need for research into the social implications of organic practices, particularly concerning labor conditions, which remains largely unexplored. While existing literature often focuses on organic agriculture’s job creation potential, the specifics of labor conditions within this sector remain insufficiently examined. Limited attention has been paid to how private certification schemes shape labour processes, or to the effects of increased preventive measures on organic farmworkers’ workloads. This study conducts a systematic review of 41 articles to assess how labor issues are framed within the organic farming sector, identifying three main themes: 1. regulatory frameworks; 2. production practices; 3. farmworkers’ employment conditions. These themes are contextualized within the global agri-food value chain, demonstrating how organic agriculture is embedded in a globalized industry. The findings suggest that the social role of organic agriculture is often framed as an economic opportunity for farmers and rural communities or as a means of promoting rural development and increasing revenues through job creation. However, such perspectives risk overlooking the sector’s potential to improve labor conditions. The review reveals an urgent need for qualitative studies that explore the experiences of marginalized groups, including migrant and female workers, in organic farming. It advocates for future research that incorporates labor issues into policy discourse, aiming to enhance labor standards within organic certification schemes. Empirical research is therefore essential to deepening our understanding of the intersection between social and environmental sustainability, particularly in relation to the varied labor regimes present in organic agriculture. This work offers a foundational basis for future studies on the evolving relationship between organic agriculture and social sustainability in the context of the green transition.202

Clinical neuroscience and neurotechnology: An amazing symbiosis

In the last decades, clinical neuroscience found a novel ally in neurotechnologies, devices able to record and stimulate electrical activity in the nervous system. These technologies improved the ability to diagnose and treat neural disorders. Neurotechnologies are concurrently enabling a deeper understanding of healthy and pathological dynamics of the nervous system through stimulation and recordings during brain implants. On the other hand, clinical neurosciences are not only driving neuroengineering toward the most relevant clinical issues, but are also shaping the neurotechnologies thanks to clinical advancements. For instance, understanding the etiology of a disease informs the location of a therapeutic stimulation, but also the way stimulation patterns should be designed to be more effective/naturalistic. Here, we describe cases of fruitful integration such as Deep Brain Stimulation and cortical interfaces to highlight how this symbiosis between clinical neuroscience and neurotechnology is closer to a novel integrated framework than to a simple interdisciplinary interaction