Double transition of young migrants in Luxembourg: vulnerable, resilient and empowering integration trajectories in the period of youth.

Migrant integration trajectories have become more complex, open, uncertain, and continuously changing, over time. For young migrants, their integration endeavour intersects with their process of transition to adulthood, a double transition that poses additional challenges. Recent theoretical perspectives such as "liquid integration" aim at focusing on the dynamic, processual, and temporal nature of migrant integration. The present article focuses on the dynamic interplay of obstacles and enablers that, over time, interact to construct complex, often non-linear, and open-ended integration and coming of age trajectories of young migrants (aged from 18 to 30 years) coming from outside the European Union (EU) to EU countries. Empirical results from the H2020 MIMY (Empowerment through liquid Integration of Migrant Youth in vulnerable conditions) research project in Luxembourg will be presented. In order to address the goal of the research, qualitative data were gathered by means of N = 38 interviews with young migrants with different migratory paths, characteristics and experiences, and specifically included: young migrants from non-EU Portuguese-speaking countries (N = 16), refugees living in reception centres (N = 15), migrants who since arriving in Luxembourg have become publicly visible (N = 7). Content analysis of the interviews allowed a twofold purpose: (1) capturing the unfolding of intersectional integration obstacles that over time play a decisive role in the building of conditions of vulnerability of the double transition under analysis; (2) capturing the multidimensional resources that interactively build up to give rise to resilient and empowering integration and coming of age experiences. The identification of decisive multidimensional obstacles and resources present in the integration endeavour during the process of coming of age allowed us to capture differentiated routes of vulnerability, on the one hand, and resilience/ empowerment on the other. Key ingredients of both vulnerable and more resilient and empowering integration and coming of age trajectories are identified as well as their relational dynamics, enabling to address key challenges for the resilience and empowerment of young migrants in the process of negotiating their transition to adulthood amidst their integration challenges in the Luxembourgish society.

Happiness Maximization Is a WEIRD Way of Living.

Psychological science tends to treat subjective well-being and happiness synonymously. We start from the assumption that subjective well-being is more than being happy to ask the fundamental question: What is the ideal level of happiness? From a cross-cultural perspective, we propose that the idealization of attaining maximum levels of happiness may be especially characteristic of Western, educated, industrial, rich, and democratic (WEIRD) societies but less so for others. Searching for an explanation for why "happiness maximization" might have emerged in these societies, we turn to studies linking cultures to their eco-environmental habitat. We discuss the premise that WEIRD cultures emerged in an exceptionally benign ecological habitat (i.e., faced relatively light existential pressures compared with other regions). We review the influence of the Gulf Stream on the Northwestern European climate as a source of these comparatively benign geographical conditions. We propose that the ecological conditions in which WEIRD societies emerged afforded them a basis to endorse happiness as a value and to idealize attaining its maximum level. To provide a nomological network for happiness maximization, we also studied some of its potential side effects, namely alcohol and drug consumption and abuse and the prevalence of mania. To evaluate our hypothesis, we reanalyze data from two large-scale studies on ideal levels of personal life satisfaction-the most common operationalization of happiness in psychology-involving respondents from 61 countries. We conclude that societies whose members seek to maximize happiness tend to be characterized as WEIRD, and generalizing this across societies can prove problematic if adopted at the ideological and policy level.

The Sense of Belonging in the Context of Migration: Development and Trajectories Regarding Portuguese Migrants in Luxembourg.

The sense of belonging can be defined as a highly subjective and dynamic feeling of acceptance, inclusion, and connectedness to a specific contextual entity. Perceiving belongingness to others is positively related to psychological well-being, happiness, or higher self-esteem. The present contribution examined how the sense of belonging to spatial, social, and cultural entities evolves over the migration process of Portuguese first-generation migrants and their second-generation offspring residing in Luxembourg. The current study drew on the qualitative content analysis of ten semi-structured interviews, carried out with ten Portuguese migrant family dyads (one parent and one adult child per dyad). The results affirmed that the sense of belonging showed to be a complex and multi-faceted concept and highly shaped by specific contexts. The initially unfamiliar Luxembourgish context became a familiar setting and even a "home" over time. While the older generation presented noticeable belongingness to Luxembourg as a homeland, their affiliation to the Luxembourgish community and culture remained rather low. Simultaneously, they preserved a high connectedness to the Portuguese culture as well as to fellow Portuguese migrants living in the Grand Duchy. The younger generation expressed a much more pronounced attachment to Luxembourg, since they perceived belongingness to the Luxembourgish spatial, social, and (multi)cultural milieu. In addition to this, a certain affiliation to the Portuguese culture and language could be discerned. Although some factors, which might have contributed to this evolution, could be identified in the present study, one can assume that there are significantly more that have not been addressed yet.

Subjective age, worry and risk-related perceptions in older adults in times of a pandemic.

During the Covid-19 pandemic, older people have been in the spotlight of the public debate. Given their higher risk of severe outcomes of the disease, they have been described as especially vulnerable and as a burden to others and society. We thus wanted to investigate how older people's perception of their own age, that is their subjective age, as well as their Covid-19 related risks and worries were related during the pandemic and whether these relationships varied according to participants' subjective health. We used data from the longitudinal CRISIS study which was conducted in the Grand-Duchy of Luxembourg in June and October 2020. Participants were aged 60-98 and responded on questionnaires regarding their subjective age, worry of falling ill with Covid-19, perceived risk of contracting the virus, perceived risk of falling seriously ill if they contracted Covid-19, as well as their subjective health and covariates. Three cross-lagged panel models were constructed to explore the longitudinal, bidirectional relationships between the variables. Cross-sectionally, a higher subjective age was related to more perceived risk of a serious course of disease. Longitudinally, subjective age and worry did not show any significant association over time, and neither did subjective age and perceived risk of contracting the virus. However, subjective health significantly moderated the relationship of worry and subjective age, showing different trajectories in the relationship depending on whether subjective health was good or bad. Higher perceived risk of falling seriously ill increased subjective age over time. Again, subjective health moderated this relationship: the perceived risk of falling seriously ill affected subjective age only for those with better subjective health. Our findings show the interactive relationship between subjective age and Covid-19 related cognitions and emotions and provide guidance for identifying older people that are most susceptible for negative age-related communication during the pandemic.

Intergenerationality in the Light of Indeterminacy.

This Special Issue aims to shed light on the undetermined nature of intergenerational trajectories. Indeterminacy has been suggested to the author as an avenue to tackle the dynamic aspect -which entails looking at tensions in an unfolding process- of intergenerationality. We present the paper in this Special Issue by insisting on their main contributions, we identify HOW they define the concept of generation, particularly in reference to indeterminacy.

In vitro assessment of polychlorinated biphenyl bioaccessibility in meat: Influence of fat content, cooking level and consumer age on consumer uptake.

In a risk assessment perspective, this work aims to assess the bioaccessibility of PCBs in meat. A standardised in vitro static digestion protocol was set up and coupled with extraction, clean-up and GC × GC-ToF/MS multianalyte method to monitor the fate of PCBs in meat during digestion. Starting with spiked meat, PCB bioaccessibility in 11% fat medium-cooked meat varied in adults from 20.6% to 30.5% according to congeners. PCB bioaccessibility increased to 44.2-50.1% in 5% fat meat and decreased to 6.2-9.1% and to 14.6-19.4% in digestion conditions mimicking infants and elderly, respectively. Intense cooking also decreased PCB bioaccessibility to 18.0-26.7%. Bioaccessibility data obtained with spiked meat were validated with measurements carried out in incurred meat samples. Finally, mean uptake distributions are obtained from a modular Bayesian approach. These distributions feature a lower mode when the fat content is higher, the meat is well-done cooked, and the consumers are older.

Perceived loneliness and the role of cultural and intergenerational belonging: the case of Portuguese first-generation immigrants in Luxembourg.

The risk of loneliness for migrants, particularly in older age, has been documented across multiple studies. Migration is a life-changing transition. While often retaining links to their country of origin, an important developmental task for migrants is the establishment of bonds in the receiving country. Drawing on recent studies, I will explore the role of cultural and intergenerational belonging in order to identify both protective and risk factors regarding loneliness in middle and older age in a sample of first-generation immigrants from Portugal living in Luxembourg. The sample comprises N = 131 participants (51.9% female) between the ages of 41 and 80 (M = 56.08; SD = 7.80) who have on average spent M = 31.71 years (SD = 8.81) in Luxembourg and raised children in Luxembourg. They took part in the IRMA project ('Intergenerational Relations in the Light of Migration and Ageing') which was funded by the Fonds National de la Recherche Luxembourg. A standardised questionnaire assessed socio-demographic data, aspects of cultural belonging (i.e. cultural attachment to both countries, bicultural identity orientation, acculturative stress), intergenerational belonging (i.e. family cohesion, family conflict, perceived intergenerational value consensus) and perceived loneliness. Results showed that while cultural and intergenerational belonging were protective factors, the strongest predictors for participants' perceived loneliness were cultural identity conflict and, even more so, intergenerational conflict. Our findings suggest that establishing roots and bonds in the host country is a protective factor against loneliness, whereas the feeling of not fitting in is a strong risk factor.

Perceived Ageism During the Covid-19-Crisis Is Longitudinally Related to Subjective Perceptions of Aging.

Ageism in media and society has increased sharply during the Covid-19-crisis, with expected negative consequences for the health and well-being of older adults. The current study investigates whether perceived ageism during the crisis longitudinally affects how people perceive their own aging. In June 2020, N = 611 older adults from Luxembourg [aged 60-98 years, Mage (SD) = 69.92(6.97)] participated in a survey on their perception of the crisis. In October 2020, N = 523 participated in a second measurement occasion. Participants reported on perceived ageism during the crisis in different domains, their self-perceptions of aging and subjective age. In latent longitudinal regression models, we predicted views on aging at T2 with perceived ageism at T1, while controlling for baseline views on aging and covariates. Perceived ageism at T1 increased self-perceptions of aging as social loss and yielded a trend for physical decline, while there were no effects on subjective age and self-perceptions of aging as continued growth. Views on aging are powerful predictors of well-being and health outcomes in later life. Our data suggest that being the target of ageism during the crisis negatively affects older adults' self-perceptions of aging and this impact may be felt beyond the current crisis.

Ageism and older people's health and well-being during the Covid-19-pandemic: the moderating role of subjective aging.

In the Covid-19 pandemic, being older means being in a special focus: Probabilities for severe infections and mortality rise with increasing age and protective measures for this population group have been increased. This was accompanied by public discourse that portrayed older adults stereotypically as vulnerable and frail but also highlighted the hardships younger people have to endure to protect them. Given the possibly detrimental effects of ageism on individuals and societies, we were interested in older adults' perception of ageism in the Corona-crisis and its relation to their health and well-being. Furthermore, we were interested in subjective aging variables as moderators in the ageism-health relationship. In June 2020, N = 611 independently living people aged 60 + from the Grand Duchy of Luxembourg were recruited via a survey research institute and interviewed online or by phone. They reported on perceived ageism in different contexts, their life satisfaction, subjective health, subjective age and self-perceptions of aging. Depending on context, ageism was perceived by around 20% of participants, and overall negatively related to subjective health and life satisfaction after the onset of the pandemic. Moderated hierarchical regressions showed that a younger subjective age buffered the negative effect of ageism on subjective health, while perceiving aging as social loss increased its effect on life satisfaction. We discuss the importance of addressing and reducing ageism (not only) in times of crisis and the consequences for individuals and societies.

Gerontagogy Toward Intergenerationality: Dialogical Learning Between Children and Elders.

This paper aims at overcoming the following limits of gerontagogy -particularly with regard to Lemieux's model: referencing chronological age; delimitating elders' learning in reference to traits (styles, needs, behaviors, etc.) in contrast to children's learning; overlooking the aging aspect. To do so, we propose to integrate aging and intergenerationality into gerontagogy from a sociocultural, dialogical and historical approach. This establishes the basis for an intergenerational and dialogical approach to elders' learning.

"I Feel More Luxembourgish, but Portuguese Too" Cultural Identities in a Multicultural Society.

The present investigation focused on cultural identity and the dealing with the belonging to different cultural frames as a migrant in a highly culturally diverse context by comparing two generations of Portuguese families living in Luxembourg. Quantitative standardized questionnaires complemented by in-depth qualitative interviews with parent-child dyads were used in order to assess possible (dis)similarities between first generation Portuguese immigrant parents and their adult children (i.e. second generation) concerning their cultural identities. Generational differences were found regarding the dealing with several cultural frames, language competences and attachment to both discussed cultures. Adult children were more prone to find themselves in a "compatible" identity orientation, compared to the parental generation. Yet, when focussing specifically on the second generation, qualitative data highlighted some issues regarding the perceived views of others on one's own cultural belonging and the perception of a certain sense of cultural identity denial from others. Our findings contribute to the existing theoretical literature on cultural identity by elucidating some major differences between immigrant parents and their adult children on how they enact the sense of belonging and the dealing with multiple cultural frames on a daily-life basis.

Ranking crop species using mixed treatment comparisons.

The mixed treatment comparison (MTC) method has been proposed to combine results across trials comparing several treatments. MTC allows coherent judgments on which of the treatments is the most effective. It produces estimates of the relative effects of each treatment compared with every other treatment by pooling direct and indirect evidence. In this article, we explore how this methodological framework can be used to rank a large number of agricultural crop species from yield data collected in field experiments. Our approach is illustrated in a meta-analysis of yield data obtained in 67 field studies for 36 different bioenergy crop species. The considered dataset defines a network of comparisons of crop species. We introduce several Bayesian MTC models based on baseline treatment contrasts and evaluate the practical advantages of these models to produce yield ratio estimates. We explore the consistency of some estimates by node-splitting and compare our results to those obtained with a classical two-way linear mixed model. Results reveal that the model showing the lowest deviance information criterion (DIC) includes both study random effects and study-specific residual variances. But all the tested models including study random effects lead to similar yield ratio estimates. The proposed Bayesian framework allows an in-depth analysis of the uncertainty in the species ranking.

Exposure assessment for dioxin-like PCBs intake from organic and conventional meat integrating cooking and digestion effects.

In this paper, exposure to Polychlorinated biphenyls (PCBs) related to bovine meat consumption is assessed based on multiples sources of data, namely data collected within the national research project "SoMeat" that objectively assesses the potential risks and benefits of organic and conventional food production systems in terms of contaminants respective contents. The work focuses on dioxin like PCBs in bovine meat in France. A modular Bayesian approach is proposed including measures after production, effect of cooking, levels and frequency of consumption and effect of digestion. In each module, a model is built and prior information can be integrated through previously acquired data commonly used in food risk assessment or vague priors. The output of the global model is the exposure including both production modes (organic and conventional) for three different cooking intensities (rare, medium, and well-done), before digestion and after digestion. The main results show that organic meat is more contaminated than conventional meat in mean after production stage and after cooking although cooking reduces the contamination level. This work is a first step of refined risk assessment integrating different steps such as cooking and digestion in the context of chemical risk assessment similarly to current microbiological risk assessments.

Family Cultures in The Context of Migration and Ageing.

Intergenerational family relations are embedded in family cultures which influence how families regulate their relations over the whole life span with regard to key issues, such as autonomy and relatedness, or support exchange and reciprocity, and which may vary inter- and intraculturally. Migrant families undoubtedly face a special situation as values and expectations from the culture of origin and from the host cultural context might differ. Not much is known yet about how migrant families adapt their family cultures to the host cultural context. The present article will focus on aspects of intergenerational family regulation by taking into account family cultures of migrant compared to non-migrant families in a life span perspective. We will illustrate our theoretical outline by presenting first results from the IRMA-study comparing Luxembourgish and Portuguese immigrant families living in Luxembourg. We focus on issues of family cohesion, enmeshment and normative expectations regarding adult children's support for their ageing parents, by drawing both on quantitative questionnaire as well as qualitative interview data. Implications for the experience of ambivalence and conflicts as well as well-being of family members from both generations will be discussed.

Added value of experts' knowledge to improve a quantitative microbial exposure assessment model--Application to aseptic-UHT food products.

In a previous study, a quantitative microbial exposure assessment (QMEA) model applied to an aseptic-UHT food process was developed [Pujol, L., Albert, I., Magras, C., Johnson, N. B., Membré, J. M. Probabilistic exposure assessment model to estimate aseptic UHT product failure rate. 2015 International Journal of Food Microbiology. 192, 124-141]. It quantified Sterility Failure Rate (SFR) associated with Bacillus cereus and Geobacillus stearothermophilus per process module (nine modules in total from raw material reception to end-product storage). Previously, the probabilistic model inputs were set by experts (using knowledge and in-house data). However, only the variability dimension was taken into account. The model was then improved using expert elicitation knowledge in two ways. First, the model was refined by adding the uncertainty dimension to the probabilistic inputs, enabling to set a second order Monte Carlo analysis. The eight following inputs, and their impact on SFR, are presented in detail in this present study: D-value for each bacteria of interest (B. cereus and G. stearothermophilus) associated with the inactivation model for the UHT treatment step, i.e., two inputs; log reduction (decimal reduction) number associated with the inactivation model for the packaging sterilization step for each bacterium and each part of the packaging (product container and sealing component), i.e., four inputs; and bacterial spore air load of the aseptic tank and the filler cabinet rooms, i.e., two inputs. Second, the model was improved by leveraging expert knowledge to develop further the existing model. The proportion of bacteria in the product which settled on surface of pipes (between the UHT treatment and the aseptic tank on one hand, and between the aseptic tank and the filler cabinet on the other hand) leading to a possible biofilm formation for each bacterium, was better characterized. It was modeled as a function of the hygienic design level of the aseptic-UHT line: the experts provided the model structure and most of the model parameters values. Mean of SFR was estimated to 10×10(-8) (95% Confidence Interval=[0×10(-8); 350×10(-8)]) and 570×10(-8) (95% CI=[380×10(-8); 820×10(-8)]) for B. cereus and G. stearothermophilus, respectively. These estimations were more accurate (since the confidence interval was provided) than those given by the model with only variability (for which the estimates were 15×10(-8) and 580×10(-8) for B. cereus and G. stearothermophilus, respectively). The updated model outputs were also compared with those obtained when inputs were described by a generic distribution, without specific information related to the case-study. Results showed that using a generic distribution can lead to unrealistic estimations (e.g., 3,181,000 product units contaminated by G. stearothermophilus among 10(8) product units produced) and emphasized the added value of eliciting information from experts from the relevant specialist field knowledge.

Estimation and evaluation of management options to control and/or reduce the risk of not complying with commercial sterility.

In a previous study, a modular process risk model, from the raw material reception to the final product storage, was built to estimate the risk of a UHT-aseptic line of not complying with commercial sterility (Pujol et al., 2015). This present study was focused on demonstrating how the model (updated version with uncertainty and variability separated and 2(nd) order Monte Carlo procedure run) could be used to assess quantitatively the influence of management options. This assessment was done in three steps: pinpoint which process step had the highest influence on the risk, identify which management option(s) could be the most effective to control and/or reduce the risk, and finally evaluate quantitatively the influence of changing process setting(s) on the risk. For Bacillus cereus, it was identified that during post-process storage in an aseptic tank, there was potentially an air re-contamination due to filter efficiency loss (efficiency loss due to successive in-place sterilizations after cleaning operations), followed by B. cereus growth. Two options were then evaluated: i) reducing by one fifth of the number of filter sterilizations before renewing the filters, ii) designing new UHT-aseptic lines without an aseptic tank, i.e. without a storage period after the thermal process and before filling. Considering the uncertainty in the model, it was not possible to confirm whether these options had a significant influence on the risk associated with B. cereus. On the other hand, for Geobacillus stearothermophilus, combinations of heat-treatment time and temperature enabling the control or reduction in risk by a factor of ca. 100 were determined; for ease of operational implementation, they were presented graphically in the form of iso-risk curves. For instance, it was established that a heat treatment of 138°C for 31s (instead of 138°C for 25s) enabled a reduction in risk to 18×10(-8) (95% CI=[10; 34]×10(-8)), instead of 578×10(-8) (95% CI=[429; 754]×10(-8)) initially. In conclusion, a modular risk model, as the one exemplified here with a UHT-aseptic line, is a valuable tool in process design and operation, bringing definitive quantitative elements into the decision making process.

Probabilistic exposure assessment model to estimate aseptic-UHT product failure rate.

Aseptic-Ultra-High-Temperature (UHT) products are manufactured to be free of microorganisms capable of growing in the food at normal non-refrigerated conditions at which the food is likely to be held during manufacture, distribution and storage. Two important phases within the process are widely recognised as critical in controlling microbial contamination: the sterilisation steps and the following aseptic steps. Of the microbial hazards, the pathogen spore formers Clostridium botulinum and Bacillus cereus are deemed the most pertinent to be controlled. In addition, due to a relatively high thermal resistance, Geobacillus stearothermophilus spores are considered a concern for spoilage of low acid aseptic-UHT products. A probabilistic exposure assessment model has been developed in order to assess the aseptic-UHT product failure rate associated with these three bacteria. It was a Modular Process Risk Model, based on nine modules. They described: i) the microbial contamination introduced by the raw materials, either from the product (i.e. milk, cocoa and dextrose powders and water) or the packaging (i.e. bottle and sealing component), ii) the sterilisation processes, of either the product or the packaging material, iii) the possible recontamination during subsequent processing of both product and packaging. The Sterility Failure Rate (SFR) was defined as the sum of bottles contaminated for each batch, divided by the total number of bottles produced per process line run (10(6) batches simulated per process line). The SFR associated with the three bacteria was estimated at the last step of the process (i.e. after Module 9) but also after each module, allowing for the identification of modules, and responsible contamination pathways, with higher or lower intermediate SFR. The model contained 42 controlled settings associated with factory environment, process line or product formulation, and more than 55 probabilistic inputs corresponding to inputs with variability conditional to a mean uncertainty. It was developed in @Risk and run through Monte Carlo simulations. Overall, the highest SFR was associated with G. stearothermophilus (380000 bottles contaminated in 10(11) bottles produced) and the lowest to C. botulinum (3 bottles contaminated in 10(11) bottles produced). Unsurprisingly, SFR due to G. stearothermophilus was due to its ability to survive the UHT treatment. More interestingly, it was identified that SFR due to B. cereus (17000 bottles contaminated in 10(11) bottles produced) was due to an airborne recontamination of the aseptic tank (49%) and a post-sterilisation packaging contamination (33%). A deeper analysis (sensitivity and scenario analyses) was done to investigate how the SFR due to B. cereus could be reduced by changing the process settings related to potential air recontamination source.

Quantitative assessment of the risk of microbial spoilage in foods. Prediction of non-stability at 55 °C caused by Geobacillus stearothermophilus in canned green beans.

Microbial spoilage of canned foods by thermophilic and highly heat-resistant spore-forming bacteria, such as Geobacillus stearothermophilus, is a persistent problem in the food industry. An incubation test at 55 °C for 7 days, then validation of biological stability, is used as an indicator of compliance with good manufacturing practices. We propose a microbial risk assessment model predicting the percentage of non-stability due to G. stearothermophilus in canned green beans manufactured by a French company. The model accounts for initial microbial contaminations of fresh unprocessed green beans with G. stearothermophilus, cross-contaminations in the processing chain, inactivation processes and probability of survival and growth. The sterilization process is modeled by an equivalent heating time depending on sterilization value F0 and on G. stearothermophilus resistance parameter z(T). Following the recommendations of international organizations, second order Monte-Carlo simulations are used, separately propagating uncertainty and variability on parameters. As a result of the model, the mean predicted non-stability rate is of 0.5%, with a 95% uncertainty interval of [0.1%; 1.2%], which is highly similar to data communicated by the French industry. A sensitivity analysis based on Sobol indices and some scenario tests underline the importance of cross-contamination at the blanching step, in addition to inactivation due to the sterilization process.

Potential application of quantitative microbiological risk assessment techniques to an aseptic-UHT process in the food industry.

Aseptic ultra-high-temperature (UHT)-type processed food products (e.g., milk or soup) are ready to eat products which are consumed extensively globally due to a combination of their comparative high quality and long shelf life, with no cold chain or other preservation requirements. Due to the inherent microbial vulnerability of aseptic-UHT product formulations, the safety and stability-related performance objectives (POs) required at the end of the manufacturing process are the most demanding found in the food industry. The key determinants to achieving sterility, and which also differentiates aseptic-UHT from in-pack sterilised products, are the challenges associated with the processes of aseptic filling and sealing. This is a complex process that has traditionally been run using deterministic or empirical process settings. Quantifying the risk of microbial contamination and recontamination along the aseptic-UHT process, using the scientifically based process quantitative microbial risk assessment (QMRA), offers the possibility to improve on the currently tolerable sterility failure rate (i.e., 1 defect per 10,000 units). In addition, benefits of applying QMRA are (i) to implement process settings in a transparent and scientific manner; (ii) to develop a uniform common structure whatever the production line, leading to a harmonisation of these process settings, and; (iii) to bring elements of a cost-benefit analysis of the management measures. The objective of this article is to explore how QMRA techniques and risk management metrics may be applied to aseptic-UHT-type processed food products. In particular, the aseptic-UHT process should benefit from a number of novel mathematical and statistical concepts that have been developed in the field of QMRA. Probabilistic techniques such as Monte Carlo simulation, Bayesian inference and sensitivity analysis, should help in assessing the compliance with safety and stability-related POs set at the end of the manufacturing process. The understanding of aseptic-UHT process contamination will be extended beyond the current "as-low-as-reasonably-achievable" targets to a risk-based framework, through which current sterility performance and future process designs can be optimised.

A meta-analysis accounting for sources of variability to estimate heat resistance reference parameters of bacteria using hierarchical Bayesian modeling: Estimation of D at 121.1 °C and pH 7, zT and zpH of Geobacillus stearothermophilus.

Predicting microbial survival requires reference parameters for each micro-organism of concern. When data are abundant and publicly available, a meta-analysis is a useful approach for assessment of these parameters, which can be performed with hierarchical Bayesian modeling. Geobacillus stearothermophilus is a major agent of microbial spoilage of canned foods and is therefore a persistent problem in the food industry. The thermal inactivation parameters of G. stearothermophilus (D(ref), i.e.the decimal reduction time D at the reference temperature 121.1°C and pH 7.0, z(T) and z(pH)) were estimated from a large set of 430 D values mainly collected from scientific literature. Between-study variability hypotheses on the inactivation parameters D(ref), z(T) and z(pH) were explored, using three different hierarchical Bayesian models. Parameter estimations were made using Bayesian inference and the models were compared with a graphical and a Bayesian criterion. Results show the necessity to account for random effects associated with between-study variability. Assuming variability on D(ref), z(T) and z(pH), the resulting distributions for D(ref), z(T) and z(pH) led to a mean of 3.3 min for D(ref) (95% Credible Interval CI=[0.8; 9.6]), to a mean of 9.1°C for z(T) (CI=[5.4; 13.1]) and to a mean of 4.3 pH units for z(pH) (CI=[2.9; 6.3]), in the range pH 3 to pH 7.5. Results are also given separating variability and uncertainty in these distributions, as well as adjusted parametric distributions to facilitate further use of these results in aqueous canned foods such as canned vegetables.