Aisha Betoko Mph

MD MPH Marie-Aline Charles

MD Régis Hankard

Anne Forhan Mph

Mercedes Bonet Phd

Marie-Josephe Saurel-Cubizolles Phd

PhD Barbara Heude

PhD Blandine De Lauzon-Guillain

Betoko Aisha
email: aisha.betoko@inserm.fr

Infant feeding patterns over the first year of life: influence of family characteristics

Keywords:

Background/Objectives: Early eating patterns and behaviors can determine later eating habits and food preferences and they have been related to the development of childhood overweight and obesity. We aimed to identify patterns of feeding in the first year of life and to examine their associations with family characteristics.

Subjects/Methods: Our analysis included 1004 infants from the EDEN mother-child cohort.

Feeding practices were assessed through maternal self-report at birth, 4, 8 and 12 months.

Principal component analysis was applied to derive patterns from breastfeeding duration, age at complementary food (CF) introduction and type of food used at 1y. Associations between patterns and family characteristics were analyzed by linear regressions.

Results:

The main source of variability in infant feeding was characterized by a pattern labeled 'Late CF introduction and use of ready-prepared baby foods'. Older, more educated, primiparous women with high monthly income ranked high on this pattern. The second pattern, labeled 'Longer breastfeeding, late CF introduction and use of home-made foods' was the closest to infant feeding guidelines. Mothers ranking high on this pattern were older and more educated. The third pattern, labeled 'Use of adults' foods' suggests a less age-specific diet for the infants. Mothers ranking high on this pattern were often younger and multiparous.

Recruitment center was related to all patterns.

Conclusion:

Not only maternal education level and age but also parity and region are important contributors to the variability in patterns. Further studies are needed to describe associations between these patterns and infant growth and later food preferences.

Introduction

Obesity is a worldwide epidemic and numerous studies have focused on the identification of its early determinants. The early postnatal period appears to be a critical window of development. Observational studies showed that rapid infant weight gain increases the risk of overweight and obesity later in childhood [START_REF] Monteiro | Rapid growth in infancy and childhood and obesity in later life--a systematic review[END_REF][START_REF] Botton | Postnatal weight and height growth velocities at different ages between birth and 5 y and body composition in adolescent boys and girls[END_REF][START_REF] Druet | Prediction of childhood obesity by infancy weight gain: an individual-level meta-analysis[END_REF] . Moreover, childhood obesity seems to track into adulthood [START_REF] Reilly | Health consequences of obesity[END_REF] increasing the risk of chronic diseases [START_REF] Morrison | Childhood risk factors predict cardiovascular disease, impaired fasting glucose plus type 2 diabetes mellitus, and high blood pressure 26 years later at a mean age of 38 years: the Princeton-lipid research clinics follow-up study[END_REF] . Early eating patterns and behaviors can determine later eating habits and food preferences [START_REF] Coulthard | Long-term consequences of early fruit and vegetable feeding practices in the United Kingdom[END_REF][START_REF] Beauchamp | Flavor perception in human infants: development and functional significance[END_REF] and they have been related to the development of childhood overweight and obesity [START_REF] Lanfer | Taste preferences in association with dietary habits and weight status in European children: results from the IDEFICS study[END_REF] . It's therefore important to identify feeding patterns that emerge in the early infancy and related factors.

Most of the pediatric societies recommend exclusive breastfeeding until 6 months of age [START_REF] Boland | Exclusive breastfeeding should continue to six months[END_REF][START_REF] Gartner | Breastfeeding and the use of human milk[END_REF][START_REF] Turck | Allaitement maternel : les bénéfices pour la santé de l'enfant et de sa mère[END_REF][START_REF] Agostoni | Complementary feeding : a commentary by the ESPGHAN Comitte on Nutrition[END_REF] .

Further, there is a general consensus on the fact that complementary feeding should not be introduced to infant diet before 4 months or delayed after 6 months. Results from various studies of infant feeding practices have shown high level of non-compliance with these recommendations. Across studies, lower maternal age and education level appeared consistently related to shorter breastfeeding duration and early complementary food (CF) introduction [START_REF] Dubois | Social inequalities in infant feeding during the first year of life. The Longitudinal Study of Child Development in Quebec (LSCDQ 1998-2002)[END_REF][START_REF] Wijndaele | Determinants of Early Weaning and Use of Unmodified Cow's Milk in Infants: A Systematic Review[END_REF][START_REF] Schiess | European Childhood Obesity Project. Introduction of complementary feeding in 5 European countries[END_REF] .

There has been a general cultural shift in eating practices over the last decades. Because more women are working longer hours outside home, there is a decrease in time spent in meal preparations and an increased use of ready-prepared foods [START_REF] Lang | Is there a culinary skills transition? Data and debate from the UK about changes in cooking culture[END_REF][START_REF] Jabs | Time scarcity and food choices: an overview[END_REF] . Much remains to be learned about how these emerging eating habits affect maternal feeding practices.

A few studies showed that dietary patterns emerge in early infancy [START_REF] Robinson | Dietary patterns in infancy: the importance of maternal and family influences on feeding practice[END_REF][START_REF] Smithers | Associations between dietary patterns at 6 and 15 months of age and sociodemographic factors[END_REF] and track into childhood [START_REF] North | Multivariate analysis of diet among three-year-old children and associations with socio-demographic characteristics. The Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) Study Team[END_REF][START_REF] Northstone | Multivariate analysis of diet in children at four and seven years of age and associations with socio-demographic characteristics[END_REF] . None of those studies have undertaken a global approach of food intake over the first year of life by taking into account type and duration of milk feeding, age at CF introduction and type of food used by the mother. Yet, breastfeeding and complementary feeding practices are interrelated [START_REF] Wright | Why are babies weaned early? Data from a prospective population based cohort study[END_REF][START_REF] Scott | Predictors of the early introduction of solid foods in infants: results of a cohort study[END_REF] and there are arguments to suggest that both influence later health [START_REF] Van Rossum | Quantification of health effects of breastfeeding : Review of the literature and model simulation[END_REF][START_REF] Ziegler | Early infant feeding and risk of developing type 1 diabetes-associated autoantibodies[END_REF] . Our aims were to identify feeding patterns over the first year of life, and to examine their associations with parental and infants characteristics.

Material and Methods

Study population

Subjects were participants of the EDEN mother-child prospective cohort (study of pre-and early postnatal determinants of child health and development). Between 2003 and 2006, the study recruited 2,002 pregnant women aged 18-45 years attending their prenatal visit before 24 weeks gestation at Nancy and Poitiers University Hospitals. Exclusion criteria were multiple pregnancies, diabetes history, illiteracy, moving outside the region planned in the next three years. The study received approval from relevant ethics committee. Files have been declared to the 'National Committee for Processed Data and Freedom' (CNIL). Written consents were obtained from each participant.

Infant feeding assessment

Our infant feeding assessment concentrated on qualitative aspects controlled by the parents and did not include amounts of food ingested, which depend for a great part on the infant.

Infant feeding mode at discharge was extracted from medical records. In the 4, 8 and 12month self questionnaires, mothers reported (1)type of milk feeding and when necessary date of breastfeeding cessation, (2)age at CF introduction. Among infants whose questionnaires were returned, reported data at the different ages were combined to estimate any and full breastfeeding duration and age at CF introduction. In EDEN study, ages of CF introduction were not collected beyond 8 months for cereals, fruit, vegetables, potatoes, fruit juice, dairy products, dairy desserts, cheeses, biscuits, or 12 months for the other foods. For infants who were not introduced to a specific food by 8 or 12 months, respectively the values 9 or 13 were attributed in order to analyze the variable quantitatively. For infants with available information on diet in at least one questionnaire, missing data for some of the key variables were imputed as follows: when mothers reported that the considered food was not introduced in the first 4 months and information was missing in the following questionnaires, the median age of introduction among all infants who have been introduced to that food between 4 and 12 months was attributed (n=27, 0.03%). The same rule was applied for those who were not introduced to foods at 8 months with missing information on at least one CF group at 12 months (n=233, 23.2%).

An additional questionnaire on type of food used for the baby at 12 months was added to the 12-month questionnaire during data collection. It collected information on type (readyprepared baby foods, home-made foods, ready-prepared adults' foods) and frequency of use (never, occasionally, regularly, always) of various food and juice groups (dairy products, soups, vegetables and fruit purees, fruit juices, biscuits, cereals, meat and fish). Subjects with >2 missing values on the listed items were excluded (n=183, 15.4%); otherwise modal value of the considered variable was imputed (n=57; 4.8%).

Other data

Between 24-28 weeks gestation, household income, maternal education and pre-pregnancy weight were obtained by interviewing the mother; maternal height was measured in a clinical examination. Paternal anthropometric measurements were collected at some point between mother's inclusion and delivery. Details on measurement protocol have been published elsewhere [START_REF] Regnault | Determinants of early ponderal and statural growth in full-term infants in the EDEN mother-child cohort study[END_REF] . When measurements were unavailable from the father, reported weight by the father (11.3%) was used, and reported height by the father (11.6%) or by the mother (6.3%) was used. Parental BMI(kg/m²) were categorized as : underweight (BMI<18.5), normal weight (18.5-<25), overweight (25-<30) and obese (BMI ≥30). Because of small number of underweight fathers in EDEN cohort (n=19; 1.0%), underweight fathers were grouped in the normal BMI categories.

From obstetrical and pediatric records, parity, infant gender, birthweight and gestational age were collected. In the 4, 8 and 12-month questionnaires, mothers were asked information about employment status and main type of childcare. Types of childcare were (1)childcare center, (2)licensed family childcare home, (3)family member, neighbor and (4)child's own home by a nanny or a regular infant sitter or parents themselves. Infants were categorized according to age of first attendance to types (1) and (2).

Missing data were handled as follows: when percentage of missing values was <5%, we imputed the modal class value (maternal education and BMI, household income, parity), otherwise subjects were grouped into a separate category (paternal BMI, childcare attendance).

Sample

Of the 2,002 recruited women, 96 were excluded because they left the study before or at delivery for personal reasons, 4 because intra-uterine death, 3 because they delivered outside the study hospitals. Birthweight was available for 1,899 newborns. The 4, 8 and 12 monthquestionnaires of 1,445 infants were returned. Because the additional questionnaire on type of food used at 12 months was added to the 12-month questionnaire during data collection, 496 of the recruited families did not receive it. Among the 1,445 families who returned the 4, 8 and 12-month questionnaires 1,187 also returned the additional questionnaire and 183 had more than 2 missing data on type of food used. The final sample consisted of 1,004 infants.

Compared with the 1,004 included, the 895 excluded mothers were younger (29.0 vs. 29.9 years old, p<0.001), less educated (44.6% vs. 59.2% university degree, p<0.001) and often multiparous (58.3% vs. 52.9%, p=0.03). Infants that were not included had lower birthweight and gestational age than that of included infants (3,252g vs. 3,302g, p=0.04; 39.1 vs. 39.4, p<0.001). There was no statistical difference on gender (p=0.18).

Patterns derivation

All the variables described in the infant feeding assessment section were considered for principal component analysis (PCA). PCA is a statistical technique that aggregates variables on the basis of the degree to which they are correlated to one another, producing components that are uncorrelated linear combinations of the initial variables and that maximize the explained variance [START_REF] Joliffe | Principal component analysis and exploratory factor analysis[END_REF][START_REF] Michels | Can dietary patterns help us detect diet-disease associations?[END_REF] . To determine the number of components to retain, we used the Kaiser criterion (eigenvalues>1) in conjunction to scree test (plot of total variance associated with each component) and interpretability of components. The first 3 components were kept from this analysis. We considered that variables with coefficients>|0.3| contribute significantly to the components. Finally, for each participant, a score was calculated as a sum of the products of the values of each of the standardized variables included in the PCA with the corresponding coefficients of the correlation matrix.

Statistical analysis

Infants' scores on the feeding patterns were used as continuous dependent variables.

Unadjusted relations between patterns scores and recruitment centre, parental (maternal education, age at delivery, BMI and employment status, parity, paternal BMI, income) and infant characteristics (gender, birthweight, gestational age, childcare attendance) were performed by Student t-test or ANOVA for categorical variables, and Spearman correlations for quantitative variables (data not shown). Quartiles of the scores were calculated for presentation purpose. Associations between the pattern scores and family characteristics were examined using multiple regression models. Analyses were executed with SAS software (version 9.2; SAS Institute). A p-value<0.05 was considered statistically significant.

Results

Family characteristics are presented in Table1. The mean birthweight was 3,302 g and 4.1% of the infants were born preterm. The mean duration of full breastfeeding since hospital discharge and age at CF introduction were 2 and 4.5 months respectively. Nearly 26% infants were introduced to solid foods before 4 months.

The first pattern (pattern-1) was characterized by high positive coefficients for introduction of all foods and use of ready-prepared vegetables, fruit purees and baby main meals but by high negative coefficients for use of home-made and ready-prepared adults' foods (Table 2). It was labeled 'Late CF introduction and use of baby foods'. The second pattern (pattern-2) was termed 'Longer breastfeeding, late CF introduction and use of home-made foods' since it showed high positive coefficients for breastfeeding duration, age of introduction of meat, fish, vegetables, fruit, potatoes, cereals, dairy products, biscuits and fruit juices and for use of home-made soups, vegetables, fruit purees and fresh meat and fish but high negative coefficients for use of baby foods. The third pattern (pattern-3) was named 'Use of adults' foods' as it was characterized by high coefficients on use of ready-prepared dairy products, soups, fruit purees, fruit juices and biscuits contrasting with lower coefficients on baby dairy products and on home-made fruit and vegetable purees, fish and meat. The patterns explained 14.7, 12.7, and 6.0% of the variation in the original data respectively. PCA properties allow maximization of variance along each pattern, contrasting individuals whose characteristics differ most [START_REF] Joliffe | Principal component analysis and exploratory factor analysis[END_REF] . Thus, for each pattern, scores define the position of each individual along a gradient. To facilitate interpretation of the pattern coefficients, distribution of the original variables within the first and fourth quartiles of the patterns scores have been presented in table 2. The higher the coefficient of a variable on a pattern, the greater is the variability in its distribution across quartiles of the patterns scores.

High scores on pattern-1 were significantly related to high family income, maternal age and education, low parity, tended to be more common in females (Table 3). Mothers of infants with high scores on pattern-2 were more likely to be older, to have high education level, and less likely to be obese. High scores on pattern-3 were significantly associated with low maternal age, being multiparous. None of the patterns was significantly related to paternal BMI and infant's gestational age.

We ran the same multivariate models, excluding premature infants (n=27, 0.03%), then excluding subjects having missing values on parental characteristics (n=88, 5.5%). Results remained similar to those presented above (data not shown). Further analyses were performed excluding infants with missing value on CF introduction between 4-12 months (n=27, 0.03%), between 8-12 months (n=233, 23.2%) and type of food use at 12 months (n=57; 4.8%).

Results were similar to those presented except for centre that was no longer significantly related to pattern-2 (0.10[-0.07, 0.26]) and pattern-3 (-0.16[-0.32, 0.01]).

Discussion

In our study, the main source of variability in infant feeding was characterized by pattern-1 labeled 'Late CF introduction and use of ready-prepared baby foods'. Older, more educated, primiparous women with high monthly income ranked high on this pattern. Pattern-2, labeled 'Longer breastfeeding, late CF introduction and use of home-made was the closest to infant feeding guidelines. Mothers with high scores on this pattern were older and more educated.

Pattern-3, labeled Use of adults' foods suggests a less age-specific diet for the infants.

Mothers ranking high on this pattern were often younger and multiparous.

Recent studies in infants have applied PCA on various food items (from food frequency questionnaires (FFQ)) to derive dietary patterns with a transversal approach [START_REF] Robinson | Dietary patterns in infancy: the importance of maternal and family influences on feeding practice[END_REF][START_REF] Smithers | Associations between dietary patterns at 6 and 15 months of age and sociodemographic factors[END_REF] . Our study is original in its longitudinal aspect: we used breastfeeding duration, age at CF introduction and type of food used at 12 months. This approach enabled us to appreciate the prospective aspect of infant feeding in the first year of life. Although some differences in variables included, our second pattern was similar to the 'infant guidelines' pattern of the Southampton Women Study [START_REF] Robinson | Dietary patterns in infancy: the importance of maternal and family influences on feeding practice[END_REF] and to the 'Breastfeeding' pattern of ALSPAC study [START_REF] Smithers | Associations between dietary patterns at 6 and 15 months of age and sociodemographic factors[END_REF] , both extracted at 6 months and characterized by longer breastfeeding, high frequency of consumption of home-made foods but low frequency of use of baby foods.

In our study, mothers of infants ranking high on pattern-1 and pattern-3, more often recruited in Nancy, were more likely to use ready-prepared foods but in pattern-1, types of food were adapted to infants whereas in pattern-3, types of food were less specific to infants. In patterns 1 and 2, age of introduction of eggs contributed little to the characterization of early or late introducers of CF, showing that the recommendation of late introduction of eggs (see table 2 footnote) is well met by the mothers in our cohort. Higher scores on pattern-1 seem to be explained by awareness of specific nutritional needs for infant, lack time or culinary skills to implement it and income allowing the use of ready-prepared infant foods. Higher scores on pattern-3 were mainly related to low maternal age and increased parity. Young mothers of our study seem to cook less and the presence of older children in the household decreases the likelihood for a specific diet for the infant. Unlike others, mothers ranking high on pattern-2, more often recruited in Poitiers, breastfed longer, introduced CF later and were more likely to cook meals. These mothers may be more aware of infant feeding guidelines and may have more time to spend for meals preparation. These findings are consistent with previous results that showed a negative relation between age, education and household size and readyprepared foods use in general population [START_REF] Brunner | Convenience food products. Drivers for consumption[END_REF][START_REF] Buckley | The convenience food market in Great Britain: Convenience food lifestyle (CFL) segments[END_REF][START_REF] Olsen | Likelihood of buying healthy convenience food: An at-home testing procedure for ready-to-heat meals[END_REF] , which may be explained by lack of time or ability and/or willingness to 'cook from scratch' [START_REF] Lang | Is there a culinary skills transition? Data and debate from the UK about changes in cooking culture[END_REF] . Local culture as well as food availability and prices play a major role in determining where, how and what foods are eaten [START_REF] Mela | Food choice and intake: the human factor[END_REF] . Type of jobs and time spent in transportation, which are likely to differ between the regions of Poitiers and Nancy may also explain the differences in feeding patterns. Nancy region is more urbanized than Poitiers region (population density of their regions in 2009: 100 people/km sq. [START_REF]The Lorraine region : Population structure and evolution[END_REF] vs. 68 people/km sq. [START_REF]The Poitou-Charentes region : Population structure and evolution[END_REF] ). We have to acknowledge that nowadays, ready-prepared foods are widely used and 'home-made' meals sometimes include the help of various readyprepared products [START_REF] Carrigan | Managing routine food choices in UK families: the role of convenience consumption[END_REF] . We were not able to evaluate this aspect in our study.

Longer breastfeeding duration has been positively associated with later CF introduction [START_REF] Wright | Why are babies weaned early? Data from a prospective population based cohort study[END_REF][START_REF] Scott | Predictors of the early introduction of solid foods in infants: results of a cohort study[END_REF] , higher maternal age and education level [START_REF] Dubois | Social inequalities in infant feeding during the first year of life. The Longitudinal Study of Child Development in Quebec (LSCDQ 1998-2002)[END_REF][START_REF] Thulier | Variables associated with breastfeeding duration[END_REF][START_REF] Kristiansen | Factors associated with exclusive breastfeeding and breast-feeding in Norway[END_REF] , parity [START_REF] Thulier | Variables associated with breastfeeding duration[END_REF][START_REF] Bolling | Infant Feeding Survey 2005. The Information Centre Part of the Government Statistical Service[END_REF] . Early CF introduction has been related to lower maternal age and education [START_REF] Dubois | Social inequalities in infant feeding during the first year of life. The Longitudinal Study of Child Development in Quebec (LSCDQ 1998-2002)[END_REF][START_REF] Kristiansen | Factors associated with exclusive breastfeeding and breast-feeding in Norway[END_REF][START_REF] Erkkola | Sociodemographic determinants of early weaning: a Finnish birth cohort study in infants with human leucocyte antigen-conferred susceptibility to type 1 diabetes[END_REF] , higher birthweight [START_REF] Wright | Why are babies weaned early? Data from a prospective population based cohort study[END_REF][START_REF] Schack-Nielsen | Late introduction of complementary feeding, rather than duration of breastfeeding, may protect against adult overweight[END_REF] and infant gender [START_REF] Kristiansen | Factors associated with exclusive breastfeeding and breast-feeding in Norway[END_REF][START_REF] Erkkola | Sociodemographic determinants of early weaning: a Finnish birth cohort study in infants with human leucocyte antigen-conferred susceptibility to type 1 diabetes[END_REF][START_REF] Alder | What influences the timing of the introduction of solid food to infants?[END_REF] . Our findings are consistent with those results. When considering the whole feeding in the first year of life, infants' characteristics were not related to the patterns except for a tendency for earlier CF introduction in boys as already published [START_REF] Kristiansen | Factors associated with exclusive breastfeeding and breast-feeding in Norway[END_REF][START_REF] Erkkola | Sociodemographic determinants of early weaning: a Finnish birth cohort study in infants with human leucocyte antigen-conferred susceptibility to type 1 diabetes[END_REF][START_REF] Alder | What influences the timing of the introduction of solid food to infants?[END_REF] . Early return to employment in the postpartum period has been negatively associated with breastfeeding duration [START_REF] Gielen | Maternal employment during the early postpartum period: effects on initiation and continuation of breast-feeding[END_REF][START_REF] Visness | Maternal employment and breast-feeding: findings from the 1988 National Maternal and Infant Health Survey[END_REF] ; relations with CF introduction have less been examined. Evidences showed that infants cared in non-parental care compared with parental care were shorter breastfed [START_REF] Kim | Association of infant child care with infant feeding practices and weight gain among US infants[END_REF][START_REF] Benjamin | Early child care and adiposity at ages 1 and 3 years[END_REF] and early introduced to CF [START_REF] Kim | Association of infant child care with infant feeding practices and weight gain among US infants[END_REF] . In our study, maternal employment and childcare attendance were not strongly associated with parental feeding practices suggesting that they are not major factors explaining the variability in infant feeding.

In accordance with other studies [START_REF] Robinson | Dietary patterns in infancy: the importance of maternal and family influences on feeding practice[END_REF][START_REF] Smithers | Associations between dietary patterns at 6 and 15 months of age and sociodemographic factors[END_REF] , we found a significant association between the feeding patterns and maternal BMI. Previous analyses suggested that women who are overweight/obese before pregnancy are more likely to discontinue breastfeeding earlier than do normal-weight women [START_REF] Hilson | Maternal obesity and breast-feeding success in a rural population of white women[END_REF][START_REF] Baker | High prepregnant body mass index is associated with early termination of full and any breastfeeding in Danish women[END_REF][START_REF] Amir | A systematic review of maternal obesity and breastfeeding intention, initiation and duration[END_REF][START_REF] Mok | Decreased full breastfeeding, altered practices, perceptions, and infant weight change of prepregnant obese women: a need for extra support[END_REF] . In our results, mothers with high scores on pattern-2 were less likely to be obese in contrast to mothers with high scores on pattern-3 who were more likely to be obese. Paternal BMI, marker of a familial obesogenic environment besides maternal BMI, was not related to the patterns.

Our study had some limitations. The EDEN population is not representative of the general population. Compared to the national perinatal survey carried out on 14,482 women who delivered in France in 2003 [START_REF] Blondel | Trends in perinatal health in metropolitan France between 1995 and 2003: results from the National Perinatal Surveys[END_REF] , women included in EDEN study were slightly older, more educated and more often employed. We were however able to show differences in infant feeding practices according to maternal age, education, household income, and region even if our sample was more homogenous than the general French population according to these criteria. We did not found association regarding employment status although our sample did not lack variability on this criterion (29% of the mothers never worked between 0-12 months).

Therefore, we believe that the relationships observed are of interest for the general population of infants born in France from middle class parents.

Our questionnaire on infant feeding has not been validated as most questionnaires used to assess food habits in infancy (ref JAND). Nevertheless, some questions were repetead in in the 4, 8 and 12-mo questionnaires, which allow to correct for inconsistency in maternal report.

As we did not use a FFQ in our study, we were not able to go into details on qualitative aspects of diet at different ages to reproduce published results. However, interesting patterns emerged from our analyses and we believe that our approach provides complementary information to existing publications on feeding practices in the first year of life. Data on breastfeeding duration and age at CF introduction were missing at some ages between 0-12 months. However we were able to retrieve information by combining data from three questionnaires. Imputations that were performed in infants with incomplete data probably lead to a loss of information in terms of variability of maternal practices but represent a fairly good approximation of early or late CF introduction/breastfeeding discontinuation according to the current guidelines.

In summary, our study allowed the identification of well individualized feeding patterns in the first year of life, which explain a large part of the variability in our samples. It highlighted that not only maternal education level and age but also parity and region are important contributors to the variability in patterns. Our results reflect constraints regarding cooking skills, spendable time on meals preparation, cost and availability of fresh foods in different regions, factors that could be analyzed in depth in future studies.

for important intellectual content. MAC is the guarantor of the study. All authors had full access to all of the data in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.

Members of the EDEN

  Mother-Child Cohort Study Group: MA Charles, A Forhan, M de Agostini, B Heude, P Ducimetière (Inserm, CESP U1018), M Kaminski, MJ Saurel-Cubizolles, P Dargent, X Fritel, B Larroque, N Lelong, L Marchand, C Nabet (Inserm U953), I Annesi-Maesano (Inserm U707), R Slama (Inserm U823), V Goua, G Magnin, R Hankard, (Poitiers University Hospital), O Thiebaugeorges, M Schweitzer, B Foliguet (Nancy University Hospital), N Job-Spira (ANRS).

Table 1 : Characteristics of parents and offspring (n=1,004).

 1

	460
	Variable

Table 2 : Description of infant feeding variables within quartiles (Q) of pattern scores and PCA coefficients, n=1004.

 2

		Pattern 1			Pattern 2			Pattern 3
	Q1	Q4	Coefficients	Q1	Q4	Coefficients	Q1	Q4	Coefficients

Table 3 : Multivariate associations between infant feeding patterns and family characteristics in EDEN cohort study, n=1004.

 3

	Feeding patterns

Acknowledgements:

We thank the heads of the maternity units, the investigators and all the women who participated in the surveys. We acknowledge all funding sources for the EDEN study: Fondation pour la Recherche Médicale (FRM), French Ministry of Research: Federative Research Institutes and Cohort Program, INSERM Human Nutrition National Research Program, and Diabetes National Research Program (through a collaboration with the French Association of Diabetic Patients (AFD)), French Ministry of Health, French Agency for Environment Security (AFSSET), French National Institute for Population Health Surveillance (InVS), Paris-Sud University, French National Institute for Health Education (INPES), Nestlé, Mutuelle Générale de l'Education Nationale (MGEN), French speaking association for the study of diabetes and metabolism (ALFEDIAM), National Agency for Research (ANR non thematic program), National Institute for Research in Public health (IRESP: TGIR cohorte santé 2008 program).

The research leading to these results has received funding from the European Community's Seventh Framework Program (FP7/ 2007-2013) under the grant agreement n°FP7-245012-HabEat.

Aisha Betoko was supported by a research grant from the French Ministry for Higher Education and Research.

Contributors:

The EDEN Study group, coordinated by MAC and BH, was responsible for study design and data collection. MAC and BLG were involved in all aspects from study conception to manuscript writing. AB, AF and MB participated in data management for the present analyses. AB analyzed and interpreted the data and wrote the initial draft of the manuscript. BH, RH, MJSC and all the co-authors critically reviewed all sections of the text


Djamal Benslimane
email: djamal.benslimane@univ-lyon1.fr

Mahmoud Barhamgi
email: mahmoud.barhamgi@univ-lyon1.fr

Frederic Cuppens
email: frederic.cuppens@telecom-bretagne.eu

Franck Morvan
email: franck.morvan@irit.fr

Bruno Defude
email: bruno.defude@it-sudparis.eu

Ebrahim Nageba
email: ebrahim.nageba@univ-lyon1.fr

PAIRSE: A Privacy-Preserving Service-Oriented Data Integration System

Privacy is among the key challenges to data integration in many sectors, including healthcare, e-government, etc. The PAIRSE project aims at providing a flexible, looselycoupled and privacy-preserving data integration system in P2P environments. The project exploits recent Web standards and technologies such as Web services and ontologies to export data from autonomous data providers as reusable services, and proposes the use of service composition as a viable solution to answer data integration needs on the fly. The project proposed new composition algorithms and service/composition execution models that preserve privacy of data manipulated by services and compositions. The proposed integration system was demonstrated

INTRODUCTION

Data integration has been a long-standing challenge for the database community. This is motivated by the number of contexts in which the need for a flexible data integration mechanism has become critical, including Web and enterprise data integration, scientific data exploration, data exchange in government agencies, etc.

Much of the literature on data integration across autonomous data sources has tacitly assumed that data on the side of each data source can be revealed and shared with other sources. In practice, however, data integration scenarios are often hampered by legitimate and widespread data privacy concerns. In the healthcare application domain for example, medical data are subject to many legislations (e.g., [START_REF]Health insurance portability and accountability act of[END_REF][START_REF] Nageba | directive on data protection[END_REF]) around the world that restrict collection, processing, and disclosure of personal data, and hold data holders accountable for any unintended data disclosure or misuse.

The PAIRSE project addresses the challenge of flexible and privacy-preserving data integration in peer-to-peer environments. Driven by the recent trends of using SOA-oriented architectures for data integration in modern enterprises, PAIRSE assumes that data sources are exposed to the data sharing environment as Web services. This type of services is commonly known as data services [START_REF] Carey | Data services[END_REF], where data services provide a well documented, platform (and source) independent, interoperable method of interacting with data. PAIRSE proposes a service composition-based approach for on-demand data integration; i.e., heterogeneous data services from autonomous service providers are selected and composed on the fly to answer users' queries. Data privacy preservation is a key objective of PAIRSE. Users in PAIRSE are allowed only to access the information they are entitled to for a given purpose. PAIRSE focuses on modeling, discovering, selecting and composing data services to efficiently answer users' queries. The contributions of PAIRSE, which was demonstrated at EDBT 2013 [START_REF] Barhamgi | Privcomp: a privacy-aware data service composition system[END_REF] and VLDB 2011 [START_REF] Benouaret | Fudocs: A web service composition system based on fuzzy dominance for preference query answering[END_REF], are summarized as follows:

• Semantic description model for data services:

The semantics of data services should be explicitly represented to automate their discovery, selection and composition. We modeled data services as "RDF Views" over domain ontologies to formally define their semantics [START_REF] Barhamgi | A query rewriting approach for web service composition[END_REF].

The service description files (e.g., WSDLs) are annotated with these RDF views.

• Query resolution by automatic service composition: Queries in PAIRSE are resolved by automatically selecting and composing data services. We exploited mature query rewriting techniques to devise a novel service composition algorithm [START_REF] Barhamgi | A query rewriting approach for web service composition[END_REF][START_REF] Benouaret | Fudocs: A web service composition system based on fuzzy dominance for preference query answering[END_REF]. The algorithm relieves users from having to manually select and com-pose services, tasks that would generally require important programming skills. We proposed also an efficient algorithm to locate relevant services in a P2P environment [START_REF] Ketata | Resource discovery considering semantic properties in data grid environments[END_REF].

• Privacy preservation: We proposed a privacy preserving composition model [START_REF] Barhamgi | Privcomp: a privacy-aware data service composition system[END_REF][START_REF] Barhamgi | Secure and privacy-preserving execution model for data services[END_REF][START_REF] Oulmakhzoune | fquery: Sparql query rewriting to enforce data confidentiality[END_REF]. Our model allows services providers to locally enforce their privacy and security policies when their services are invoked. In addition, it prevents services in a composition from learning any information about the data that each other holds, beyond what is permitted.

The rest of the paper is organized as follows. Section 2 gives an overview of our integration system. Section 3 describes our semantic modeling of data services. Section 4 presents our composition approach. Section 5 presents our techniques to privacy preservation. Section 6 applies our work in two application domains, and summarizes obtained results. Section 7 concludes the paper.

PAIRSE'S ARCHITECTURE

The PAIRSE data integration system has a hybrid peer-to-peer infrastructure [START_REF] Ketata | Resource discovery considering semantic properties in data grid environments[END_REF], where peers form communities of interest, called Virtual Organizations VOs. Each VO has a common domain ontology modeling its expertise, and peer members that may have relations with members from other VOs. Relations between peers exist only if there is a mapping between the ontologies of their respective VOs. PAIRSE does not impose any constraint on the topology graph formed by the ontologies and the different mappings. Peers export their (sharable) data sources as data services.

PAIRSE follows a declarative approach to compose data services (Figure 1). Data services in each peer are modeled as RDF Views over domain ontologies to explicitly define their semantics. Users formulate their queries on domain ontologies using SPARQL query language. Then, our system exploits the defined RDF views (added as annotations to service description files) to select and compose the relevant services using an RDF query rewriting algorithm that we have devised for that purpose. Queries may necessitate the use of remote data services, in which case an efficient P2P service discovery algorithm [START_REF] Ketata | Resource discovery considering semantic properties in data grid environments[END_REF] is used to locate and retrieve the descriptions of relevant services from remote peers. The system generates then an execution plan for the composition and executes it to provide the user with the requested data. As data services may manipulate privacy-sensitive information, PAIRSE proposed new service and composition execution models to preserve privacy.

SEMANTIC MODELING AND SERVICE QUERYING

In this section, we explain our service composition based approach to query resolution.

Semantic Modeling of Data Services

Modeling and explicitly specifying the semantics of data services are the first step towards the automation of service selection and composition.

In PAIRSE, we proposed in [START_REF] Barhamgi | A query rewriting approach for web service composition[END_REF] to model data services as RDF Parameterized Views (RPVs) over domain ontologies. A parameterized RDF view uses concepts and relations whose meanings are formally defined in domain ontologies to define the semantic relationships between input and output parameters sets of a data service. A parameterized view is a technique that has been used to describe content and access methods in Global-as-View (GaV) integration architectures [START_REF] Halevy | Answering queries using views: A survey[END_REF]. Figure 2 shows an RPV of a service returning the personal information (i.e., name and dates of birth) of patients admitted in a given medical center. Note that input parameters are prefixed with the symbol "$" and output parameters are prefixed with the symbol "?".

RDF views may also specify constraints to characterize the data manipulated by their corresponding services. These constraints may have different forms, including simple interval constraints (e.g., X ∈ [a, b], where X is a variable used in an RDF view), and fuzzy constraints interpreted according to a fuzzy membership function (e.g., the medications returned by a service have "High" concentration of hydroxypropy1-β-cyclodextrin; i.e., X is High, where the fuzzy term "High" is interpreted by a membership function specifying for each value of X the degree to which it is high).

We adopted an approach similar to SAWSDL

Service-based Query Resolution

In PAIRSE, users' queries are resolved by composing relevant data services on the fly. Each virtual organization in PAIRSE's hybrid P2P architecture has a DHT (Distributed Hash Table ) to index its published services [START_REF] Ketata | Resource discovery considering semantic properties in data grid environments[END_REF]. Services are indexed according to the ontological concepts used in their RPVs.

When a query is issued at a given peer, relevant services are first sought in the same V O where the query is posed, then the service discovery request is propagated to connected V Os. The descriptions of discovered services are then sent back to the initial peer, where the relevant services will be selected and composed. Furthermore, for each discovered service we return the mapping path between the ontologies associated with the expertise domains (i.e., VOs) of the discovered service and the initial peer. This mapping path allows the translation of RPV views.

We proposed a query rewriting based service composition algorithm to select and compose data services on the fly [START_REF] Barhamgi | A query rewriting approach for web service composition[END_REF][START_REF] Benouaret | Fudocs: A web service composition system based on fuzzy dominance for preference query answering[END_REF]. The algorithm, given a SPARQL query, and a set of data services represented by their RPVs, rewrites the query in terms of calls to relevant services. Our algorithm extends earlier works on query rewriting and data integration [START_REF] Halevy | Answering queries using views: A survey[END_REF] in the following aspects:

Compliance with the RDF/S data models: while most of previous work has focused on relational and XML data integration [START_REF] Halevy | Answering queries using views: A survey[END_REF][START_REF] Yu | Constraint-based xml query rewriting for data integration[END_REF], we considered the case of RDF/RDFS data integration. Specifically, our query rewriting algorithm takes into account RDF schema constraints such as rdfs:subClassOf, rdfs:subPropertyOf, rdfs:domain, and rdfs:range when comparing RPVs to queries. The consideration of RDFS constraints is important as allows our system to infer more results than the previous rewriting techniques. For example, suppose there is a statement in an RDFS ontology specifying that :Medication rdfs:subClassOf :Drug. Given a data service S returning the medications administered to a given patient, and a query Q for the drugs administered to a given patient, our algorithm automatically infers that S can be used to generate rewritings for Q.

Answering parameterized queries: while previous data integration systems have focused on answering specific queries, PAIRSE has focused on answering parameterized queries. The key focus was on constructing compositions of services (i.e., parameterized integration plans) that are independent of a particular input value. For example, assume a parameterized query Q($x, ?y) for the medications y that may interact with a given medication x. Assume also two data services: S 1 ($x,?y), where x ∈ [1, 5] and y ∈ [100,150], S 2 ($x,?y), where x ∈ [6,10] and y ∈ [150,200] If Q was a specific query (Q x=2 ), then S 2 would not be considered in the rewriting (i.e., composition) as x=2 is not covered by S 2 . In contrast, both of S 1 and S 2 are usable for Q, to cover as much as possible of the potential values of x. Our composition algorithm extends the previous ones with: (i ) a probabilistic subsumption test to determine in a polynomial time the minimum number of services required to satisfy the value constraints that may be specified on query's parameters [START_REF] Barhamgi | Optimizing daas web service based data mashups[END_REF], and (ii ) a mechanism to optimize the generated composition plans based on value constraints specified in service descriptions [START_REF] Barhamgi | A query rewriting approach for web service composition[END_REF].

Inclusion of user's preferences: often the number of candidate compositions that may be used to answer the same query is very large. We proposed an approach [START_REF] Benouaret | Fudocs: A web service composition system based on fuzzy dominance for preference query answering[END_REF] to compute the top-k compositions based on user preferences. In our approach, we modeled user's preferences using fuzzy sets. We match the (fuzzy) constraints of the relevant services to those of the query and determine their matching degrees using a set of matching methods from the fuzzy set theory. We then rank-order candidate services based on a fuzzification of Pareto dominance and compute the top-k compositions.

PRIVACY PRESERVATION IN PAIRSE

In this section, we briefly present our models to preserve the privacy of manipulated data at the service and the composition levels.

Privacy-preserving Service Execution Model

Data returned by a data service may be subject to different security and privacy concerns. For example, different people may have different access rights over the same data item; data subjects have different preferences about the disclosure of their data, etc. A common approach in the database field to handle such concerns is to push them to the underlying DBMS by rewriting the query to include these constraints [START_REF] Lefevre | Limiting disclosure in hippocratic databases[END_REF]. However, this may not be applicable to data services as the same service may access a multitude of heterogeneous data sources that may not be necessarily managed by a DBMS. An alternative approach is to enforce privacy and security policies at the application level [START_REF] Ashley | Enforcing privacy within an enterprise using ibm tivoli privacy manager for e-business[END_REF], by modifying, in our case, the source code of data services. However, this may not always be applicable, as most of current data service creation platforms (e.g., AquaLogic [START_REF] Carey | Data services[END_REF]) provide data services as black boxes that cannot be modified. Even if the code was modifiable, this approach often leads to privacy leaks [START_REF] Lefevre | Limiting disclosure in hippocratic databases[END_REF]. We proposed a secure, privacy-preserving execution model for data services allowing service providers to enforce their privacy and security policies without changing the implementation of their data services (i.e., services are seen as black boxes). Our model is inspired by the database approach to "declaratively" handle the security and privacy concerns. It involves the following steps (refer to Figure 3):

Step 1: View rewriting to integrate security and privacy constraints. When a data service is invoked, our model rewrites its corresponding RDF view to take into account applicable security and privacy rules from the service's associated policies, which are expressed using the OrBAC and PrivOrBAC models over domain ontologies and take into account the data recipient (i.e., service consumer), his purpose for requesting the data, and the consents of data subjects [START_REF] Oulmakhzoune | fquery: Sparql query rewriting to enforce data confidentiality[END_REF]. The soundness and correctness of our algorithm are demonstrated in [START_REF] Oulmakhzoune | fquery: Sparql query rewriting to enforce data confidentiality[END_REF][START_REF] Barhamgi | Secure and privacy-preserving execution model for data services[END_REF].

Step 2: Rewriting the extended view in terms of data services. The extended RDF view v extended may include additional data items (denoted by ∆v = v extended -v original ) required to enforce security and privacy constraints. In this step, we find the data services covering ∆v, and rewrites v extended in terms of these services along with the initial service.

Step 3: Enforcing security and privacy constraints. Services selected in the previous step are composed and executed using the conventional service execution process. The composition returns (i ) the data items returned by the invoked service along with (ii ) the data items necessary to evaluate the security and privacy constraints. We defined a privacy filter that evaluates the privacy constraints of the different items that are subject to privacy constraints in the view. Null values will be returned for items whose privacy constraints evaluate to False.

We demonstrated the validity of our model by extending the architecture of the famous service container AXIS 3 2.0 with a new module implementing our privacy-preserving service execution model.

Privacy-preserving Composition Execution Model

Executing compositions may disclose confidential information to component services. Assume, for example, a composition of two services: S 1 returns HIV patients in a given city, and S 2 checks whether a given patient has been treated for psychiatric disorders. Such composition could be needed (by a pharmaceutical researcher) to investigate the connection between a chemical component present in HIV medicines and the development of severe psychiatric disorders. Assume also Bob is a common patient to S 1 and S 2 . If S 2 is invoked with Bob's identifier, and the provider of S 2 has an access to the composition plan (i.e., he knows that Bob was outputted by S 1 ), then he will infer that Bob is an HIV patient. On the other hand, if the data returned by S 1 were completely privacy-sanitized (e.g., by removing identifiers and sensitive information), then the composition could not be executed.

We proposed a privacy-preserving composition execution model in [START_REF] Barhamgi | Privcomp: a privacy-aware data service composition system[END_REF] that limits the information disclosed to services in a composition about the data that each other holds. Our model distinguishes between the following entities: (i ) the services in the composition, (ii ) the execution engine, and (iii ) the recipient of final results. It relies on two key ideas: First, data services use the same order-preserving encryption scheme OPES [START_REF] Agrawal | Order-preserving encryption for numeric data[END_REF] to encrypt the identifier attributes that are needed to connect data subjects across the different services. They are still free to protect non-identifier attributes with their own techniques (e.g., anonymization, etc.). This way the execution engine has only access to protected data and can still link data subjects across services using the encrypted identifier attributes (note that OPES allows for applying equality queries on encrypted data). By the end of the composition execution, it removes from the final results the encrypted identifier attributes before returning them to the recipient, who will thus get only privacy-sanitized data. Second, we proposed a algorithm to allow the execution engine to generalize the encrypted value v e received from a service S i before proceeding with the invocation of the subsequent service S j in the composition, such that the generalized value Gen(v e ) corresponds to k input encrypted values for which S j has outputs; e.g., the identifier of Bob is generalized to cover k -1 other patients for which S 2 has an output (i.e., S 2 will not be able to distinguish between Bob and k -1 other patients).

IMPLEMENTATION AND EVALUATION

We evaluated our different techniques and algorithms in the healthcare and bioinformatics application domains. These domains have widely embraced Web standards, such as XML and Web services [START_REF] Dogac | Interoperability in ehealth systems[END_REF][START_REF] Bhagat | Biocatalogue: a universal catalogue of web services for the life sciences[END_REF], and are characterized by the need for a flexible and privacy-preserving data integration approach.

The cardiology hospital of Lyon provided us with access to two medical databases. The identities of patients in these databases were changed. We also generated synthetic medical data about the same patients. We implemented about /400/ data Web services on top of our real and synthetic data. Services were all deployed on an extended version of AXIS 2.0 implementing our service execution model. We built a medical ontology based on the building blocks and the data types defined in the HL7 standard, and used it for the annotation of service description files. To evaluate our techniques in the bioinformatics domain, we used a set of /300/ services from the BioCatalogue registry 4 .

Figure 4 (part a) shows the query interface to PAIRSE. Users are assisted in formulating their SPARQL queries over domain ontologies. The figure shows (in part b) also the composition plan of a selected composition, along with the privacy-sanitized results (part c).

We conducted exhaustive experiments to evaluate the performance of our integration system. We summarize below obtained results5 : Composition construction and execution : Our experiments in [START_REF] Barhamgi | A query rewriting approach for web service composition[END_REF] showed that our composition algorithm can handle hundreds of data services in a reasonable time. For example, for chain queries [START_REF] Halevy | Answering queries using views: A survey[END_REF] and RPVs with a length of 3 or 4 object properties the algorithm was able to handle up to 400 services in less than 4 seconds.In the context of parameterized queries, our experiments in [START_REF] Barhamgi | Optimizing daas web service based data mashups[END_REF] showed that our algorithm to find the minimum set of services introduced only a small cost at the composition construction time (i.e., in all experiments the algorithm required less than 10% of the time needed to rewrite the query), and improved substantially the composition execution time (i.e., in all experiments the composition execution time was reduced to less than 0.75% of the time needed without optimization), as it removes redundant services. In the context of preferences queries, our experiments in [START_REF] Benouaret | Fudocs: A web service composition system based on fuzzy dominance for preference query answering[END_REF] considered that services can be grouped in classes. The experiments showed that the top-k compositions can be computed efficiently. For instance, for classes containing about 400 services, the top-k compositions are computed in less than 4 seconds.

Security and privacy preservation : The conducted experiments in [START_REF] Barhamgi | Secure and privacy-preserving execution model for data services[END_REF] showed that our secure and privacy preserving service execution model added only a small increase to the service execution time. In all experiments, the cost incurred in the enforcement of security and privacy constraints did not exceed 10% of the time required to execute the service with ignoring these security and privacy constraints altogether. The conducted experiments for the evaluation of our composition execution model [START_REF] Barhamgi | Privcomp: a privacy-aware data service composition system[END_REF] showed that the time required to execute the composition with privacy preservation is at most three orders of magnitude of the time required without privacy preservation (K i was set to 4 in all tests). We were able to cut down that cost to two orders of magnitude by reusing the values of the protocol parameters that were computed in past invocations of the same services (and during the same composition execution).

CONCLUSION

The goal of the PAIRSE project was to develop new methods and techniques for flexible and privacypreserving data integration. We have evaluated our composition-based approach in the healthcare and the bioinformatics domains. The obtained results [START_REF] Barhamgi | Privcomp: a privacy-aware data service composition system[END_REF][START_REF] Benouaret | Fudocs: A web service composition system based on fuzzy dominance for preference query answering[END_REF][START_REF] Barhamgi | A query rewriting approach for web service composition[END_REF][START_REF] Ketata | Resource discovery considering semantic properties in data grid environments[END_REF][START_REF] Barhamgi | Secure and privacy-preserving execution model for data services[END_REF][START_REF] Oulmakhzoune | fquery: Sparql query rewriting to enforce data confidentiality[END_REF][START_REF] Barhamgi | Optimizing daas web service based data mashups[END_REF] are promising.

ACKNOWLEDGMENTS

PAIRSE is funded by the French National Research Agency under the grant number ANR-09-SEGI-008

ADDITIONAL AUTHORS

Michael Mrissa (Lyon 1 University, michael.mrissa @univ-lyon1.fr), Francois Paulus (Semsoft Company, francois.paulus@semsoft-corp.com), Stephane Morucci (Swid Company, stephane.morucci@swid.fr), Nora Cuppens (Telecom-Bretagne, nora.cuppens@telecombretagne .eu), Chirine Ghedira (Lyon 3 University, chirine.ghedira -guegan@univ-lyon3.fr), Riad Mokadem (Paul Sabatier University, Riad.Mokadem@irit.fr), Said Oulmakhzoune (Telecom-Bretagne, said.oulma khzoune@swid.fr) and Jocelyne FAYN (INSA-Lyon, Jocelyne.Fayn@insa-lyon.fr).

Figure 1 :

 1 Figure 1: Peer Structure

Figure 2 :

 2 Figure 2: (a) a parameterized RDF view; (b) its graphical representation associate data services with their RPVs. We exploited the extensibility feature of the WSDL standard to annotate the WSDL files with RPVs.

Figure 3 :

 3 Figure 3: A Privacy-preserving Service Execution Process

Figure 4 :

 4 Figure 4: (a) Query interface; (b) The selected composition; (c) Obtained results

Service-based Query Processing

	Peer Structure
	P2P Service Discovery		RDF Query Rewriting			SPARQL Query	Client
						Results
			Composition
		Plan Generation
	Service Registry		Composition
	WSDL-S				Privacy-preserving
					Composition Execution
	Annotated WS
	descriptions
	Modeling Services as RDF views over Domain Ontologies + Annotating the Service Descriptions	S a	S b	S i	S n	Data Services
	with the Defined Views
	Ontologies
		DB	DB	DB	DB	Data Sources

  2 may

	Si's conventional	execution	Si's RDF View Rewriting Security & Privacy Enforcement Security & Privacy policies p Si's RDF View Composition Service-based View Rewriting Service Registry Si invocation extended with S&P constraints Results S S i request Privacy-sanitized response
			S i 's privacy-preserving execution

We use the term data subject to mean the individual whose information is manipulated by data services.

http://www.biocatalogue.org/

For detailed information about the considered settings in each cited experiment, please refer to the corresponding paper.