New Program Abstractions for Privacy

Static program analysis, once seen primarily as a tool for optimising programs, is now increasingly important as a means to provide quality guarantees about programs. One measure of quality is the extent to which programs respect the privacy of user data. Differential privacy is a rigorous quantified definition of privacy which guarantees a bound on the loss of privacy due to the release of statistical queries. Among the benefits enjoyed by the definition of differential privacy are compositionality properties that allow differentially private analyses to be built from pieces and combined in various ways. This has led to the development of frameworks for the construction of differentially private program analyses which are private-by-construction. Past frameworks assume that the sensitive data is collected centrally, and processed by a trusted curator. However, the main examples of differential privacy applied in practice - for example in the use of differential privacy in Google Chrome’s collection of browsing statistics, or Apple’s training of predictive messaging in iOS 10 -use a purely local mechanism applied at the data source, thus avoiding the collection of sensitive data altogether. While this is a benefit of the local approach, with systems like Apple’s, users are required to completely trust that the analysis running on their system has the claimed privacy properties. In this position paper we outline some key challenges in developing static analyses for analysing differential privacy, and propose novel abstractions for describing the behaviour of probabilistic programs not previously used in static analyses

BEHAVIORAL AND PHYSIOLOGICAL DRIVERS OF OBESITY: AN INVESTIGATION USING A SENSORY APPROACH

La patologia dell\u2019obesit\ue0 attualmente pu\uf2 essere considerata una malattia a eziologia multifattoriale. I dati relativi allo studio delle variabili che sono profondamente radicate nella mente umana e che determinano le abitudini, tuttavia, sono relativamente scarsi. Studi recenti hanno ipotizzato che i fattori legati alla percezione sensoriale forniscono informazioni utili per indagare il fenomeno dell\u2019incremento di peso. La percezione e il gradimento del cibo, infatti, sono il risultato di molteplici stimoli sensoriali, visivi, olfattivi, gustativi, e somatosensoriali. In particolare, gli stimuli olfattivi e gustativi giocano un ruolo centrale nella scelta degli alimenti, nell'accettabilit\ue0 e, di conseguenza, nell'assunzione di energia. Nonostante la relazione tra percezione sensoriale e assunzione di cibo sia evidente, gli studi disponibili anche su questo argomento sono limitati, i risultati sono contraddittori e non facilmente confrontabili. L'obiettivo generale di questa tesi di dottorato \ue8 stato quello di studiare le variabili comportamentali e fisiologiche coinvolte nel fenomeno dell\u2019obesit\ue0 utilizzando un approccio sensoriale, attraverso: a) la valutazione della sensibilit\ue0 gustativa, della neofobia alimentare e del gradimento alimentare in soggetti normopeso e obesi; b) lo studio delle interazioni multisensoriali (odore-gusto-consistenza) in un alimento modello (crema dessert) e del gradimento in relazione al sesso e allo stato nutrizionale; c) la valutazione dell'influenza dell'esposizione agli stimoli olfattivi nell\u2019ambiente circostante sulla salivazione, sull\u2019appetito e sull'assunzione di cibo. I risultati hanno dimostrato che i soggetti obesi hanno una distorta sensibilit\ue0 gustativa rispetto ai soggetti normopeso. In particolare, i soggetti obesi coinvolti sono risultati meno sensibili agli stimoli gustativi rispetto ai soggetti normopeso. Queste differenze nella percezione gustativa potrebbero portare i soggetti con un elevato indice di massa corporea (IMC) ad avere diverse preferenze alimentari rispetto ai soggetti normopeso, prediligendo prodotti alimentari ricchi per esempio di zuccheri e grassi, in grado di sopperire alla ridotta sensibilit\ue0. Questa ipotesi \ue8 avvalorata dai punteggi di gradimento significativamente pi\uf9 elevati dati dai soggetti obesi ai prodotti ad alta densit\ue0 energetica rispetto ai soggetti normopeso. Differenze significative non sono state invece riscontrate tra gli indici di neofobia alimentare nei due gruppi di soggetti coinvolti. Le interazioni multisensoriali (odore-gusto-consistenza) si sono dimostrate diverse in relazione all\u2019IMC e, in misura minore, al sesso. Infatti, l\u2019aggiunta di aromi e agenti addensanti a un prodotto modello (crema dessert) ha generato maggiori interazioni sensoriali (odore-gusto, odore-flavor e odore-consistenza) soprattutto nelle donne con elevato IMC rispetto al gruppo di controllo. L\u2019aggiunta di uno stimolo riconducibile a prodotti ad alta densit\ue0 energetica, come per esempio l\u2019aroma di burro, ha infatti modificato la percezione di caratteristiche sensoriali in modo pi\uf9 efficace nei soggetti obesi rispetto al gruppo di controllo. Gli individui obesi hanno, per esempio, percepito l\u2019aumento della dolcezza in seguito all\u2019aggiunta di aroma burro senza una effettiva aggiunta di zucchero al prodotto. Infine, l'esposizione agli odori nell\u2019ambiente circostante ha influenzato sia le risposte comportamentali sia quelle fisiologiche coinvolte nel consumo alimentare. L'esposizione agli odori riconducibili a prodotti ad alta densit\ue0 energetica, in particolare, ha aumentato la quantit\ue0 consumata di un prodotto modello (riso al cioccolato), la salivazione e l\u2019appetito. La capacit\ue0 degli odori di influenzare la quantit\ue0 di cibo ingerito e, quindi, la quantit\ue0 di energia assimilata, potrebbe essere uno strumento utile per prevenire l'eccessivo consumo di cibo da parte degli individui sovrappeso e obesi e guidarli verso scelte pi\uf9 sane. In conclusione, lo studio dell\u2019obesit\ue0 utilizzando un approccio sensoriale risulta interessante e innovativo per una miglior comprensione del fenomeno e per la messa a punto di strategie che ne contrastino lo sviluppo. Gli stimoli sensoriali, infatti, potrebbero essere utilizzati nell\u2019indirizzare i consumatori a una minore assunzione di cibo e verso scelte di prodotti alimentari pi\uf9 salutari. Inoltre, considerando i meccanismi di integrazione degli stimoli sensoriali a livello cerebrale si potrebbero sviluppare nuovi prodotti alimentari a ridotto apporto calorico, soddisfacenti per il consumatore.It is well known that the pathology of obesity is considered a disease with a multifactorial etiology. However, fairly poor data have been reported on the influence of variables which are deeply-rooted in human mind and determine food habits. Recent evidences have suggested that factors related to the sensory perception may explain weigh excess. Indeed, food perception and food liking are the result of multiple sensory modalities, including visual, olfactory, gustatory, and somatosensory inputs. In particular, the odor and taste cues of foods play a pivotal role in food choice, acceptability and, thus, energy intake. Despite the relationship between sensory perception and food intake is evident, the studies available on this topic are very few in number and results are rather contradictory and not easy to compare. The overall aim of this Ph.D. thesis was to study behavioral and physiological variables involved in the phenomenon of obesity using a sensory approach. Specific goals were: 1) the evaluation of taste sensitivity, food neophobia and food liking in normal-weight and obese subjects; 2) the study of multisensory interactions (odor-taste-texture) in a model food (custard dessert) and food liking in relationship with gender and nutritional status; 3) the evaluation of the influence of ambient odor exposure on salivation, appetite and food intake. The results showed that obese subjects differed in terms of taste sensitivity from normal-weight subjects. More specifically, the obese subjects involved were less sensitive to taste stimuli compared to the lean subjects. These differences may lead subjects with higher BMI to prefer foods rich, for example, in sugar and fat in order to compensate their reduced sensitivity. This hypothesis is supported by the liking scores, provided by obese subjects, to the high energy dense food products which were significantly higher compared to the scores given by the normal-weight subjects. No differences in food neophobia scores have been found in the two groups of subjects. The multisensory interactions (odor-taste-texture) occurred differently in relation to BMI and, to a lesser extent, to gender. Indeed, a model food (custard dessert) modified with aromas and thickener agents produced strongest sensory interactions (odor-taste, odor-flavor and odor-texture) in subjects with higher BMI, especially in women, compared to the control group. The addition of a stimulus signaling high-calorie products, such as butter aroma, modified the perception of different sensory characteristics in a more effective way in obese subjects compared to the normal-weight. For example, obese subjects perceived the modified samples, added with butter aroma, as sweater without the addition of sugar. Finally, the ambient odors exposure affected behavioral and physiological responses involved in eating behavior. In particular, the exposure to odor signalling high-energy dense food products increased the total eaten amount of a model food (chocolate rice), the salivation and the appetite. The ability of odors to influence the amount of food ingested, and therefore the amount of energy assimilated by individuals, could be a useful instrument to prevent overeating in obese individuals steering food intake away from high energy unhealthy foods, towards healthier choices. In conclusion, it is evident that investigate the phenomenon of obesity applying an innovative sensory approach is interesting in order to better understand and stem the complex issue of overeating. Indeed, it could be possible to drive food preferences, food choices and food intake focusing on sensory cues. How the mechanism of brain integration occurs in subjects with different nutritional status might be taken in to account in order to develop new food products with a reduced caloric intake but satisfying for the consumer

Exploring perceptive drivers and barriers to the consumption of plant-based alternatives

Nowadays, a major global challenge is to find healthy and sustainable alternative food sources to meet the growing demand for food. One of the strategies adopted to reduce the environmental impact of the food system is the development of plant-based foods used as substitutes for animal products (i.e. plant-based meat analogues, plant-based dairy alternatives). Although consumers are increasingly aware of the environmental impact of their food choices, barriers to the transition towards these products still exist. In this context, the aims of this study were to: a) obtain a sensory mapping of animal product alternatives of the Italian market b) identify the main perceptive drivers of acceptability and rejection of plant-based products.  A sample of adult consumers (n ≥ 100; age > 18 years) balanced according to gender and age was recruited. Consumers were asked to taste and rate their overall liking of commercial plant-based foods and to perform a Check-All-That-Apply (CATA) task to describe the samples. Consumers also completed questionnaires to investigate their food consumption behaviour.  Through this study, a sensory database of plant-based products was defined based on compositional, nutritional and sensory characteristics. This database showed that there is a large diversity within the same food category with reference to the raw ingredients used and the sensory characteristics. Furthermore, through Principal Coordinate Analysis, obtained by linking liking data with CATA descriptions, the drivers of liking and rejection towards these food products were identified. Further analyses are in progress to verify the effect of consumers eating behaviour on the acceptability of these products.  The present study provides useful information for food companies for identifying potential reformulation opportunities and product development. Indeed, the optimization of the sensory and nutritional properties of plant-based food is a key strategy to improve its liking and to promote its consumption with consequent environmental and health benefits

Advantages and pitfalls of the Rate-All-That-Apply method to characterize large and heterogenous wine samples

It is well known that descriptive sensory analysis is the most powerful tool to quantitatively profile products and obtain a complete sensory description. However, conventional descriptive sensory methods have the limitation of being able to describe a small number of similar samples and being time consuming and expensive. The aim of this study was to investigate the suitability and reliability of the Rate-All-That-Apply method (RATA) to characterize a large and heterogeneous Italian wine samples involving a small number of semi-trained judges. Twelve judges evaluated 46 samples including white, red, rosé, and sparkling wines in two replicates. Judges were asked to select from a list of descriptors all the sensations that described the samples and to evaluate their intensity on a 5-point scale. Results showed that the panelists had an adequate performance as a whole and individually. Judges obtained high repeatability index scores (arbitrary cut-off > 0.50), meaning that they were consistent with the descriptors’ selection in the replicates. Panel reliability was further assessed in terms of reproducibility of whole sensory characterization by evaluating the configurational similarity of product spaces obtained from the two separate replicates through a Multi Factor Analysis (MFA). This analysis showed that replicates of all wines were located near in the bidimensional space. MFA results also showed a good discriminatory ability of the method with red wines described by bitterness, astringency, body, alcohol, and specific olfactory stimuli such as red fruits, spicy and roasted, while white wines were salty, sour, and characterized by citrus, tropical fruits and white flowers odors. The RATA method proved to be an adequate, alternative descriptive method for characterizing heterogeneous wines, making it extremely useful for producers and/or small companies to characterize their portfolio of wines. Advantages (user-friendly, rapid) and pitfalls (R.I. too optimistic with large descriptors list) of RATA method were highlighted

Impact of ambient odors on food intake, saliva production and appetite ratings

The aim of this study was to investigate the effect of ambient odor exposure on appetite, salivation and food intake. 32 normal-weight young women (age: 21.4\ua0\ub1\ua05.3\ua0year; BMI: 21.7\ua0\ub1\ua01.9\ua0kg/m2) attended five test sessions in a non-satiated state. Each participant was exposed to ambient odors (chocolate, beef, melon and cucumber), in a detectable but mild concentration, and to a control condition (no-odor exposure). During each condition, at different time points, participants rated appetite for 15 food products, and saliva was collected. After approximately 30\ua0min, ad libitum intake was measured providing a food (chocolate rice, high-energy dense product) that was congruent with one of the odors they were exposed to. A significant odor effect on food intake (p\ua0=\ua00.034) and salivation (p\ua0=\ua00.017) was found. Exposure to odors signaling high-energy dense products increased food intake (243.97\ua0\ub1\ua022.84\ua0g) compared to control condition (206.94\ua0\ub1\ua024.93\ua0g; p\ua0=\ua00.03). Consistently, salivation was increased significantly during chocolate and beef exposure (mean: 0.494\ua0\ub1\ua00.050\ua0g) compared to control condition (0.417\ua0\ub1\ua00.05\ua0g; p\ua0=\ua00.006). Even though odor exposure did not induce specific appetite for congruent products (p\ua0=\ua00.634), appetite scores were significantly higher during odor exposure (p\ua0<\ua00.0001) compared to the no-odor control condition and increased significantly over time (p\ua0=\ua00.010). Exposure to food odors seems to drive behavioral and physiological responses involved in eating behavior, specifically for odors and foods that are high in energy density. This could have implications for steering food intake and ultimately influencing the nutritional status of people

Migliore sensibilità sensoriale nei non vedenti: mito o realtà?

Alcuni studi suggeriscono che la privazione di uno o più sensi (ad esempio, la vista) potrebbe aumentare la sensibilità degli altri sensi. Risultati contrastanti sono stati evidenziati, con alcuni autori che riportano che i soggetti non vedenti e ipovedenti mostrano una maggiore sensibilità olfattiva rispetto ai soggetti vedenti, mentre altri studi hanno mostrato una performance olfattiva comparabile. Non sono presenti in letteratura risultati riguardanti la percezione sensoriale dei soggetti non vedenti per altre modalità sensoriali, come il gusto e il tatto a livello della cavità orale. L'obiettivo è stato quello di confrontare la percezione sensoriale (gustativa, olfattiva e tattile nella cavità orale) tra soggetti non vedenti/ipovedenti e vedenti. Diciotto soggetti vedenti e quindici non vedenti/ipovedenti sono stati testati per la loro: a) capacità di identificare stimoli olfattivi (Test di Identificazione degli Odori con Sniffin' Sticks); b) capacità di riconoscere stimoli gustativi (Test delle Strisce Gustative) e c) valutazione della percezione tattile (filamenti di Von Frey). I risultati preliminari hanno rilevato una capacità comparabile di identificare gli stimoli olfattivi in entrambi i gruppi di soggetti. Allo stesso modo, non sono state riscontrate differenze tra i soggetti non vedenti/ipovedenti e i vedenti nel riconoscimento dei gusti. I soggetti non vedenti/ipovedenti sono risultati confrontabili al gruppo di controllo anche per quanto riguarda la percezione tattile orale. Questi risultati suggeriscono che la privazione visiva sembra non portare a differenze nella percezione sensoriale nell'olfatto, nel gusto e nella percezione tattile. In conclusione, sembra che, contrariamente alle credenze comuni, la compensazione tra i sensi nei soggetti non vedenti/ipovedenti non avvenga per nessuna delle modalità sensoriali indagate

Determinants of obesity in Italian adults : the role of taste sensitivity, food liking, and food neophobia

Recent evidence has suggested that factors related to sensory perception may explain excess weight. The objective of this study was to consider multiple aspects while investigating the phenomenon of obesity. One goal was to compare taste acuity (taste threshold and density of fungiform papillae) in both normal weight and obese subjects. Thresholds for 4 basic tastes and the fat stimulus were investigated. A second research goal was to study the relationship between food neophobia and food liking according to the body mass index and taste sensitivity. The results showed that obese subjects seem to have higher threshold values and a reduced number of fungiform papillae than do normal weight subjects. Food neophobia did not vary with nutritional status, whereas differences were found for food liking, with obese subjects showing significantly higher liking ratings for high energy dense products compared with normal weight subjects

Designing All Graphdiyne Materials as Graphene Derivatives: Topologically Driven Modulation of Electronic Properties

Designing new 2D systems with tunable properties is an important subject for science and technology. Starting from graphene, we developed an algorithm to systematically generate 2D carbon crystals belonging to the family of graphdiynes (GDYs) and having different structures and sp/sp(2) carbon ratios. We analyze how structural and topological effects can tune the relative stability and the electronic behavior, to propose a rationale for the development of new systems with tailored properties. A total of 26 structures have been generated, including the already known polymorphs such as alpha-, beta-, and gamma-GDY. Periodic density functional theory calculations have been employed to optimize the 2D crystal structures and to compute the total energy, the band structure, and the density of states. Relative energies with respect to graphene have been found to increase when the values of the carbon sp/sp(2) ratio increase, following however different trends based on the peculiar topologies present in the crystals. These topologies also influence the band structure, giving rise to semiconductors with a finite band gap, zero-gap semiconductors displaying Dirac cones, or metallic systems. The different trends allow identifying some topological effects as possible guidelines in the design of new 2D carbon materials beyond graphene

The role of nutritional and sustainability information on consumer’s acceptance of gluten-free formulations fortified with pulses

Pulses represent an ingredient for enriching food formulations with beneficial consequences both on human health and sustainability of the agri-food system, since their production requires the exploitation of few natural resources. The aims of this study were to: a) evaluate consumer acceptance and expectations of whole corn-based gluten-free formulations fortified with pulses flour; b) investigate the effect of sustainability and health information on overall liking. A sample of 127 consumers evaluated five food formulations: a whole corn-based gluten-free control sample and four experimental samples fortified with 20% of raw or pre-gelatinized red lentils or chickpea flours, respectively. Consumers were asked to evaluate overall liking under blind (only tasting), expected (only information) and real condition (information + tasting) and to complete a questionnaire about their food behaviour and sustainability commitment. ANOVA results showed that all samples were well accepted in blind condition (M: 57.6–62.7) with no significant differences between samples fortified with pulses and control sample. The information provided during the expected condition led to a general significant increase (p&lt;0.001) in the hedonic ratings compared with the blind ones. An incomplete assimilation effect resulted for pre-gelatinized samples, while it was complete for the raw chickpea sample. In conclusion, new food formulations well accepted by consumers could be developed with pulses flours. Furthermore, information regarding food sustainability and health effects about the use of pulses as new food ingredient may positively influence consumers’ expectations and subsequent liking. Therefore, promoting the benefits of these products can be a powerful strategy to encourage their consumption and encourage consumer choice. Further analyses are in progress to verify the effect of information in consumers’ segments differing for commitment to sustainability, food neophobia and health and taste attitudes

Sweet liking predicts liking and familiarity of some alcoholic beverages, but not alcohol intake: A population study using a split-sample approach

Sweetness has been proposed to be an important quality in the decision to consume alcohol, and strong preferences for sweet tastes have been associated with alcohol abuse. However, alcohol is characterized by a number of other sensory properties, including astringency and bitterness that may drive preference and consumption. Spinelli et al. (2021) classified individuals into three sweet-sensory liking clusters (High Sweet-Liking, Moderate Sweet-Liking, and Inverted-U) that differed in their sweetness optima and sensory-liking patterns (relationship between liking and sweetness, bitterness and astringency perception in a food model). The current paper replicates the sweet sensory-liking clusters in a new set of participants (n = 1976), and extends the predicted value of these clusters examining their relationship to wine and other types of alcoholic beverages by gender using a split-sample approach on a total of over 3000 adults. The sweet sensory-liking clusters had a predictive relationship for the familiarity and liking of some alcoholic beverages characterized by stronger tastes, but not weekly alcohol intake levels. Thus, although sweet sensory-liking clusters may be associated with the type of beverages and frequency with which a person will drink and enjoy a type of alcoholic beverage, they are poor predictors of the quantity of alcohol that a person ingests over the course of a week