Valorization of mullet roe by-products for the production of polyunsaturated fatty acids rich oils

This work examines the potential valorization of mullet roe by-products for the production of mullet roe oil using mild processes. Three different extraction methods with potential of scale-up for the food industry, namely pressure (PE), supercritical fluid extraction (SFE), and solvent extraction (SE) are examined. Mild temperature conditions to prevent oil oxidation and (wherever applicable) food-grade solvents are used. The oil yield, the composition of oils in fatty acids by GC-FID, the level of oil oxidation (peroxide value (PV), p-anisidine value (AV), K₂₃₂ K₂₆₈, TOTOX)) and the antioxidant activity (DPPH, ABTS) are determined. SE provided the highest oil recovery, followed by SFE and PE (68%, 28% and 10% respectively). The extracted oils had a high concentration of EPA and DHA and a total of 20.7%–24.3% of identified PUFAs among the fatty acids. Oxidation was the lowest in the SFE extracted oil followed by PE, PV was <2.5 meq_O2, AV≤10 and TOTOX <15 in all examined oil samples. Further research is needed to optimize processing conditions for the increase in oil recovery.     

Working in the sky: A diary study on work engagement among flight attendants.

This study aims to gain insight in the motivational process of the Job Demands-Resources (JD-R) model by examining whether daily fluctuations in colleague support (i.e., a typical job resource) predict day-levels of job performance through self-efficacy and work engagement. Forty-four flight attendants filled in a questionnaire and a diary booklet before and after consecutive flights to three intercontinental destinations. Results of multilevel analyses revealed that colleague support had unique positive effects on self-efficacy and work engagement. Self-efficacy did not mediate the relationship between support and engagement, but work engagement mediated the relationship between self-efficacy and (in-role and extra-role) performance. In addition, colleague support had an indirect effect on in-role performance through work engagement. These findings shed light on the motivational process as outlined in the JD-R model, and suggest that colleague support is an important job resource for flight attendants helping them reach their work-related goals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Migration of styrene from plastic packaging based on polystyrene into food simulants

Migration of potentially toxic substances from plastic packaging materials is very important in the food industry since it determines the suitability of polymers when used in food packaging. In this work, results are presented on the migration of styrene monomer from plastic packaging based on either rigid or foamed polystyrene. Water, ethanol/water solution and isooctane (resembling oil) were considered as food simulants. Experiments were carried out at various temperatures and migration was tested from 30 min to 30 days. Measurements were carried out using gas chromatography with external calibration and styrene standard solutions. No styrene was measured in water, except at high temperatures and long time periods, while the amount in ethanol/water was always grater than that in isooctane. Finally, the styrene diffusion coefficients for all the various experimental conditions were estimated using a rigorous model based on the Fick diffusion equation and the partitioning of the monomer between the two phases and consequently the activation energy of the migration process was evaluated. Copyright © 2011 Society of Chemical Industry     

Job resources boost work engagement, particularly when job demands are high.

This study of 805 Finnish teachers working in elementary, secondary, and vocational schools tested 2 interaction hypotheses. On the basis of the job demands-resources model, the authors predicted that job resources act as buffers and diminish the negative relationship between pupil misbehavior and work engagement. In addition, using conservation of resources theory, the authors hypothesized that job resources particularly influence work engagement when teachers are confronted with high levels of pupil misconduct. In line with these hypotheses, moderated structural equation modeling analyses resulted in 14 out of 18 possible 2-way interaction effects. In particular, supervisor support, innovativeness, appreciation, and organizational climate were important job resources that helped teachers cope with demanding interactions with students. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A profile of information systems research in the Mediterranean region

Drawing data from the Mediterranean Conference on Information Systems (MCIS), we build a profile of Mediterranean information systems (IS) research and compare the emerging research landscape with recent reviews in European and international contexts. We report on research topics addressed, research methodologies employed, local empirical contexts and the composition of the related community of authors. On the basis of this data, we problematize on the meaningfulness and nature of a regional profile for IS research. Together with the six papers selected for this special issue, we aspire to contribute to the broader discourse on the diversity of IS research orientation, methodologies and agendas across different parts of the world.     

Stakeholder analysis as a front-end to knowledge elicitation

Knowledge elicitation is one of the more problematic phases of knowledge based systems development. Two specific problems that have received inadequate attention in the literature are the process of expert selection and the use of a broader, socially and politically informed, frame of reference for knowledge elicitation. This paper builds on the few attempts to consider these problems. It contributes to a novel interpretation of the broader knowledge acquisition context using the powerful notion of stakeholders. More specifically, it proposes the application of an interpretive stakeholder analysis approach previously developed in information systems research. It is argued that the identification of knowledge based systems’ and knowledge elicitation stakeholders and the investigation of their viewpoints not only enriches the knowledge elicitation process, it also contributes to a broader understanding of knowledge based systems development.     

Evaluating the Role of Probiotics in the Prevention and Management of Age-Related Diseases

The human lifespan has been significantly increased due to scientific advancements in the management of disease; however, the health span of the aging population does not follow the same trend. Aging is the major risk factor for multimorbidity that is derived from the progressive loss of homeostasis, immunological and stem cell exhaustion, as well as exacerbated inflammation responses. Age-related diseases presenting with high frequencies include neurodegenerative, musculoskeletal, cardiovascular, metabolic diseases and cancer. These diseases can be co-morbid and are usually managed using a disease-specific approach that can eventually lead to polypharmacy, low medication adherence rates and undesired drug-drug interactions. Novel studies suggest targeting the shared biological basis of age-related diseases to retard the onset and manage their manifestations. Harvesting the anti-inflammatory and immunomodulatory capacity of probiotics to tackle the root cause of these diseases, could pose a viable alternative. In this article, a comprehensive review of the effects of probiotic supplementation on the molecular pathogenesis of age-related diseases, and the potential of probiotic treatments as preventative or alleviatory means is attempted. Furthermore, issues on the safety and efficiency of probiotic supplementation, as well as the pitfalls of current clinical studies are discussed, while new perspectives for systematic characterization of probiotic benefits on aged hosts are outlined.